A Comparative Evaluation of Shear Bond Strength of by xgl15815

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									  A Comparative Evaluation of Shear Bond Strength of
Integracem with Fuji-Ortho-Lc on Unetched Enamel and
 Scanning Electron Microscopic Study of the Debonded
         Enamel Surface - An In-Vitro Study

               Dissertation submitted to
    THE TAMILNADU DR. M.G.R. MEDICAL UNIVERSITY
         in partial fulfillment of the degree of



          MASTER OF DENTAL SURGERY




                   BRANCH – V

                 ORTHODONTICS

                  FEBRUARY 2005
                           CERTIFICATE
     THIS IS TO CERTIFY THAT DR. S.M. KAYALVIZHI, POST GRADUATE
STUDENT (2002-2005) IN THE DEPARTMENT OF ORTHODONTICS, TAMIL
NADU GOVT. DENTAL COLLEGE & HOSPITAL, CHENNAI-03 HAS DONE
THIS DISSERTATION TITLED “A COMPARATIVE EVALUATION OF
SHEAR BOND STRENGTH OF INTEGRACEM with                FUJI-ORTHO-LC ON
UNETCHED ENAMEL AND SCANNING ELECTRON MICROSCOPIC
STUDY OF THE DEBONDED ENAMEL SURFACE - AN INVITRO STUDY”
UNDER OUR DIRECT GUIDANCE AND SUPERVISION IN PARTIAL
FULFILLMENT OF THE REGULATIONS LAID DOWN BY THE TAMILNADU
DR. M.G.R. MEDICAL UNIVERSITY, CHENNAI, FOR M.D.S., (BRANCH – V
ORTHODONTICS) PART - II DEGREE EXAMINATION.


Dr. L. MUTHUSAMY, M.D.S.,
                                         Dr. W.S. MANJULA, M.D.S.,
       Professor & Head
                                             Additional Professor
     Dept. of Orthodontics
                                             Dept. of Orthodontics
Tamil Nadu Govt. Dental College
                                        Tamil Nadu Govt. Dental College
          & Hospital,
                                         & Hospital, Chennai – 600 003.
       Chennai – 600 003.




                    Dr. T.R. SUDARSAN, M.D.S.,
                             PRINCIPAL
              Tamil Nadu Govt. Dental College & Hospital,
                          Chennai – 600 003.
                       CONTENTS



S.No.        TITLE


1.      INTRODUCTION

2.      AIMS AND OBJECTIVES

3.      REVIEW OF LITERATURE

4.      MATERIALS AND METHODS

5.      RESULTS

6.      DISCUSSION

7.      SUMMARY AND CONCLUSION

8.      BIBLIOGRAPHY
                               INTRODUCTION


      The quality of orthodontic treatment is constantly being improved with
increasing sophistication of techniques and orthodontic bonding materials that
benefits both the patient and the clinician.
      Buonocore13 opened a new horizon in dentistry when he discovered acid
etching in 1955. Newman63 heralded the onset of direct bonding in orthodontics by
combining acid–etching with composite resins for improving their mechanical
retention.
      Acid etching produces selective dissolution of enamel leading to surface
micro – porosities which permitted the resin to penetrate and form tags thereby
enhancing mechanical retention. Significant enamel loss occurred during acid
etching and in an average it was between 10µm to 30µm, the resin tags penetrated
and extended upto 50µm. After debonding and adhesive clean up procedures, a
possibility of loss of upto 55.6µm of surface enamel was evident.85
      The iatrogenic effects of acid etching on enamel requires special attention. It
includes enamel fractures and cracks following debonding, discolouration of
enamel due to retention of resin tags, rough enamel surface and decalcified white
spots around the bracket. 54
      The advantages of acid–etching technique like adequate bond strength, ease
of application and low bond failure rate overshadowed the disadvantages and still
remains as the principal enamel conditioning technique.
      Various alternative procedures to acid–etching have been proposed. Crystal
Growth or Crystal Bonding54,55 involved application to enamel 40% polyacrylic
acid with 3.8% sulphate ions for 4 minutes which caused the growth of calcium
sulphate dihydrate (CaSO42H2O) crystals on enamel. These crystals in turn retain
the adhesives and since the bond strength was relatively low, it is not considered as
a practical technique6.
      Air abrasion or sand–blasting or micro–etching is a technique in which
particles of aluminum oxide are propelled against the surface of enamel by high air
pressure causing abrasion of the surface. Bond strength was found to be only 50%
of the acid-etch technique and surface irregularity was more.112
      Laser Etching involves application of laser energy to enamel surface which
cause localized melting and ablation, removal of enamel resulted primarily from
micro–explosion of the entrapped water in the enamel and melting of some
hydroxyapatite crystals. Thermal effects of laser etching on enamel sub-structure is
iatrogenic and required further research. 92
      Since all the surface conditioning procedures have some disadvantages,
refinements in orthodontic bonding, has formulated the production of a new dental
adhesive INTEGRACEM or High–Q–Bond (BJM laboratories,                            Or-
Yehuda, Israel) which is a fourth generation dentin bonding agent, capable of
bonding to UN-ETCHED ENAMEL, along with an enamel bonding agent –
INTEGRABOND. This saved the chair–side time during routine strap–up plus it
was easy and convenient for the patient and the operator.
      A study on IntegraCem on un-etched enamel was undertaken by Doron
Harari, Immanuel and Gillis28 (2002). They reported that IntegraCem had
adequate shear bond strength (SBS) for bonding orthodontic brackets and bond
failures occurred at enamel – adhesive interface enabling more efficient enamel
clean up, thereby preventing any potential enamel loss or crack propagation
following de-bonding.
       The present study was undertaken to evaluate the efficacy of IntegraCem in
bonding orthodontic brackets to un-etched enamel and to determine the mode of
bond failure following debonding.
                     REVIEW OF LITERATURE


       Acid etching of enamel has been a pre-requisite for successful bonding of
orthodontic attachments inspite of its hazards. It is one of the most effective ways
of improving marginal seal and mechanical bonding of the resin.
       A clear trend has emerged to reduce the enamel loss and save chair – side
bonding time without affecting clinical performance. Maintaining a sound,
unblemished enamel surface after debonding the bracket is also a primary concern
to the clinician.
       The literature is thus reviewed with an attempt to highlight the effects of
various enamel conditioning techniques with special importance to adhesive
materials that have been used on unetched enamel.


       Bounocore M.G.13 (1955) revolutionized the field of bonding with a major
break through by introducing the technique of acid etching. He demonstrated that
pre-treatment of enamel with orthophosphoric acid increased the surface area of
enamel and produced mechanical interlocking of resin to enamel.
       Newman G.V.63 (1965) introduced the technique of direct bonding by
combining acid – etching with composite resins for bonding orthodontic brackets.
He used Bis-GMA resins instead of epoxy resins which had a disadvantage of
prolonged setting time.
      Bounocore and Gwinett et al14 (1968) conducted a study to determine the
penetration pattern of resins on etched enamel surface and demonstrated that prism
like tags of range 25 µm in length were projecting from the resin into the enamel.
      Wei and Lee110 (1971) using microprobe X–ray spectrometry demonstrated
that enamel lost during etching was completely remineralised.
      Gwinett39 (1971) studied the morphological changes produced on the enamel
by etching. Three basic etching patterns were observed.
Type – 1→ Prism core material was resolved leaving the prism peripheries
             relatively intact giving a “honey comb” appearance.
Type – 2 → Peripheral regions were dissolved leaving the prism– cores intact.
Type–3→Surface loss occured without exposing the underlying enamel prisms.


      Cadwell and Johannessen16 (1971) studied the possibility of using citric
acid as an etching agent. It was proven to be useful in conditioning tooth surface
prior to the placement of Glass – ionomer cement.
                              9
      Brauer and Termini          (1972) reported that Lactic Acid, a monohydroxy
carboxylic acid was an effective adhesion promotor.
      Silver Stone94 (1974) showed that etching the enamel surface with
phosphoric acid resulted in a superficial etched zone and underlying porous zones.
Depth of etched zone depended on the acid concentration, duration of etching and
chemical composition of surface enamel.
      Reynolds79 (1975) in a review of orthodontic bonding proposed that a
maximum bond strength of 60 – 80kg/cm2 (5.9 – 7.8 MPa) would be required for
successful clinical bonding. Adhesives with an invitro bond strength of 50kg/cm2
was found to be sufficient.
                                                   47
      Kaizeres, Tencate J.M. and Arends J               (1976) investigated a number of
resin systems and their adhesiveness to enamel as well as to the bracket. The
maximum bond strength to enamel was found to be 121 kg / cm2 and the same for
bracket was 53 kg / cm2. This revealed that the attachment of adhesive to bracket
was the bottleneck of the direct bonding procedure.
                          61
      Moin and Dogon           (1977) found that the most consistent and uniform
etching was obtained with solution of 30 – 40% Phosphoric acid range. A 37%
unbuffered phosphoric acid solution applied for 60 seconds led to a surface enamel
loss of 2 – 3µm. Higher concentrations of acid removed more surface enamel in
some areas than others.
                                    59
      Martin Brannstorm et al            (1977) in their study on the effect of acid
etching on enamel and dentin had shown that etching with 37% phosphoric acid for
a variable time of 15 seconds or 2 minutes gave no apparent difference in the
microscopic appearance of enamel and dentin.
                          54
      Maijer and Smith         (1979) determined the use of crystalline interface to
increase the bond strength of adhesives to orthodontic brackets with polyacrylic
acid. It involved the application of 40% polyacrylic acid solution for 4 minutes
containing 3.8% sulphate ions. The sulphate reacted with calcium and formed a
dense growth of small needle shaped crystals. Those crystals inturn retained the
adhesive.
      Rezk Lega et al 80 (1979) evaluated the tensile bond force of Glass Ionomers
in direct bonding of orthodontic brackets in an invitro study and found that the
composite resin had a significantly higher bond force (15.25 N) than Glass
ionomers (5.5 to 27.53 N).
                                           41
      Hormati, Fuller and Denehy                (1980) studied the effects of saliva
contamination on the quality of acid etched enamel and its effect on shear bond
strength of the resin. The bond strength reduced by 50% and that simple drying of
the saliva was not sufficient. Scanning electron micrographs (SEM) demonstrated
the etched enamel with porosities to be plugged with moisture. Consequently, the
resin tag depth was insignificant for adequate retention.
                         64
      Nordenvall et al        (1980) observed no difference in etching effect between
15 and 60 seconds in deciduous teeth with 37% weight phosphoric acid whereas in
young permanent teeth 15 seconds of etching was sufficient. The old permanent
teeth often required 60 seconds of etching procedure for more retention.
      Jassem and Retief 43 (1981) conducted a study on the effects of temperature
cycling variations that occurred in the bond strength and found that it did not have
any significant differences in tensile and shear bond strength.
                                             15
      Buzzita, Hallgren and Powers                (1982) evaluated three direct bonding
cement-bracket systems invitro and found that unfilled acrylic cements gave the
highest values of bond strength for both the plastic and ceramic brackets and
highly filled diacrylate cements gave the highest values of bond strengths for metal
brackets.
                                6
      Artun and Bergland            (1984) used a solution of dilute sulphuric acid and
sodium sulphate to produce crystals. In the next step, 10% phosphoric acid was
added to the above solution. When compared with the acid etch technique, the
failure rate was found to be significantly higher with the first solution than that
with the second and also the second solution was found to have less strength than
phosphoric acid. The crystals produced were blunt.
      Artun J and Bergland 6 (1984) introduced more complex means of defining
the site of bond failure by adhesive remnant index (ARI). The score ranged
between 0 – 3 and the criteria for scoring are as follows:
      Score 0 –    No adhesive left on the tooth
      Score 1 –    Less than half of the adhesive left on the tooth.
      Score 2 –    More than half of the adhesive left of the tooth.
      Score 3 –    All the adhesive left of the tooth with distinct impression
                   of the bracket mesh.
                               7
      Barkmeirer et al             (1985) showed the retentive character of the etched
surface which was similar for both 15 or 60 seconds application timings. He
advocated short acid etching for clinical orthodontics to reduce the enamel loss.
      Maijer and Smith 55 (1986) listed the iatrogenic after effects of acid etching.
          1. Fracture and cracking of enamel during debonding
          2. Loss of acquired fluoride in the outer 10 µm of enamel surface.
          3. Discoloration of enamel due to retention of resin tags.
          4. Decalcification around brackets
                  111
      White LW          (1986) illustrated the method of bonding bracket with Glass
Ionomer Cement which had the advantage of bonding to unetched enamel and also
had the disadvantage of less bond strength when compared to composite resins.
Early saliva contamination and use of light archwire immediately were to be
avoided as the material needed 24 hours for the final setting reaction.


      Farquahar RL 34 (1986) compared crystal bonding with acid etch technique.
Shear bond strength for polyacrylic acid was found to be approximately one third
of the phosphoric acid. Total enamel loss was minimal.
                         73
      Pretorius et al      (1988) compared the etching effect of 25% pyruvic acid
with 37% phosphoric acid and found no significant clinical difference.
                          96
      Smith GA et al           (1988) evaluated the bond strength of two orthodontic
adhesives (Concise) and (System-1) to treated porcelain surfaces and assessed the
effects of thermocycling. Surface roughening and silane treatment achieved bond
strengths that were clinically successful. The effects of thermocycling were not
significant.
                         114
      Yamada et al             (1988) studied the effects of a sealant resin and the filler
content on shear and tensile bond strength of six direct bonding orthodontic
adhesives. Results indicated that the bond strength was not directly related to the
filler content. Scanning electron microscopic (SEM) observations of the debonded
mesh surfaces showed no difference between those with and without sealant for the
microfilled group where as for the heavily filled resin group, the irregular fissured
surface with microvoids got reduced with the sealant.
                 26
      Diedrich         (1989) concluded from his study that 10% of enamel was lost
during etching, bracket removal and clean up after debonding. He believed that an
orthodontic adhesive that could eliminate the need for acid etching may be
desirable in future.
                                    81
      Rod Green Law et al                (1989) compared the shear bond strength of visible
light cured system with the chemically cured composites. Bond strength was
significantly high and enamel loss following debonding was less with visible light
cured system than the heavily filled chemical cure composites.

                                                              8
      Bowen RL, Eichmiller FC, Marjenhoff WA                      (1989) had discussed about
several enamel and dentin bonding systems, noting differences in chemical
components and instructions for use. They had reported that enamel bonding
agents had no adhesion to enamel but were capable of promoting optimum resin
tag formation.
                 23
      Cook PA          (1990) compared the shear bond strength of no mix composite
resin with Glass Ionomers. The results indicated that the bond strength of Glass
Ionomers were not as good as composite resin. He stated that drying of teeth
before Glass ionomer use was not necessary but cotton rolls were required for
isolating the field of operation.
                       109
      Wei Nan Wang           (1991) compared the tensile bond strength, debonding
interface distribution and enamel surface detachment of various concentrations of
phosphoric acid from 2% to 80% applied for 15 seconds. The results showed that
10% - 30% concentrations of phosphoric acid applied for 15 seconds had adequate
bond strength with minimal enamel detachment.
      Hitt and Frigal RJ 40 (1992) conducted an invitro comparison of shear bond
strength of Scotch-Bond (Dual cure) on saliva contaminated and uncontaminated
enamel. The results were similar for both groups and the bond strength were
comparable to other conventional adhesives.
                        45
      John P Fricker         (1992) reported a 12 month clinical trial for Glass
Ionomer Cement for the direct bonding of orthodontic brackets and compared it
with a standard composite bonding adhesive. The failure rates were found to be
20% for Glass Ionomer Cement and 5% for composite resins.
                                   5
      Anne M. Compton et al            (1992) assessed the shear bond strength of
stainless steel brackets to enamel using a light cured glass ionomer cement and
rapidly setting chemically cured Glass Ionomers. The results showed increased
mean shear bond strength for light cured Glass Ionomers at 1 hour and 24 hours.
There was a faster setting reaction for light cured Glass Ionomers and its higher
initial and sustained bond strength made it more attractive for use in orthodontic
bonding.
                                  25
      Der. Horng Sheen et al           (1992) analysed the bond strength of young
permanent and other permanent teeth with various etching times and concluded
that 15 seconds etching was optimal.
      Triolo105 (1993) compared the use of maleic acid to phosphoric acid as an
etching agent. Their results indicated that 10% maleic acid provided bond strength
essentially equal to that of 37% phosphoric acid. Scanning Electron Microscopic
studies of enamel surface treated with maleic acid revealed similar morphological
pattern but the depth of etched surface was significantly less with maleic acid.
      Smith RT et al 97 (1993) compared the various dual cements with chemically
cured and light cured composites for bonding stainless steel brackets. It was
reported that the shear bond strength of dual cements were adequate to withstand
orthodontic forces and increased control of setting time allowed the clinician to
position the bracket precisely. It also permitted to remove the excess resin before
curing.
      William A. Witlshire112 (1994) compared the shear bond strength of stainless
steel brackets bonded with Glass Ionomers with and without etching and it was
compared with a no mix composite bonding resin. No mix adhesive had a higher
shear bond strength than Glass Ionomers. Enamel etching with 37% phosphoric
acid increased the magnitude of adhesion of Glass Ionomers to enamel and
improved the bond strength.
                              107
      Wasundhara A et al            (1995) studied the shear bond strength of metallic
brackets with 5% and 37% phosphoric acid. Their results showed that there was
no significant difference in the shear bond strength when the enamel surface was
etched with 5% and 37% phosphoric acid.


      Elliot Silverman et al 31 (1995) measured the tensile bond strength of Glass
Ionomers that bonded brackets to teeth without etching in the presence of saliva. It
exhibited enough resistance to forces that were needed to move the teeth. The
debonding procedures were also completely undamaging to the underlying enamel
surfaces. No decalcification was observed as glass ionomer releases fluoride.
Thus it saved time during routine strap up and made it easy for the operator.
      Redlich M, Harari D, Shoshan S 78 (1996) compared superbond crown and
bridge adhesive and High-Q bond in dogs to assess the bio-compatibility of
cementing materials. Buccal Class V cavities with sub-gingival margins were
restored with super bond and High-Q-Bond. Inflammatory resorption in gingiva
was observed after superbond but not with High-Q-Bond.
      Zachrisson et al 115 (1996) evaluated the effects of various porcelain surface
treatments (sandblasting, silane application, intermediate resin or etching with
hydrofluoric acid) on the tensile strength of orthodontic brackets bonded to
feldspathic metal ceramic porcelain using Bis-GMA resin (Concise) and 4 –
META resin (MCP – Bond). Samples were thermocycled 1000 times from 5° to
55° and then tested under tension. It revealed significantly lowered mean shear
bond strength of both the resins to feldspathic porcelain.
                                        20
      Ching Lang Meng et al                  (1997) compared the bond strength and
debonding interface distribution of adhesive with and without the use of
fluoridated etch on enamel before bonding. They concluded that the fluoridated
etch containing 1.23% sodium fluoride on enamel for 15 seconds, displayed
fluoride content on the enamel surface and did not affect the bond strength or
debonding interface analysis.

                    66
      Oslen et al        (1997) evaluated the effects of scotch bond multipurpose on
maleic acid as alternative methods of bonding orthodontic brackets to minimize
enamel surface damage. The results indicated that the use of 10% maleic acid
produced bond failure at the enamel adhesive interface.
                            62
      Neme and Kohn              (1997) investigated the claim of multipurpose dental
adhesives to increase the bond strength of amalgam and composite to tooth
structure using seven contemporary adhesive systems. The highest bond strength
was observed with Clearfil Liner Bond – 2 to enamel and dentin to be 26.4 MPa
and 24.51 MPa to amalgam.
                          72
      Pramod K Sinha           (1997) compared the potential of matrix bound fluoride
releasing adhesive with commercially available orthodontic adhesive. Matrix
bound fluoride adhesive had the potential to prevent the initiation or progression of
decalcification to frank caries and could be used successfully for the entire
duration of orthodontic treatment and shear bond strength was also adequate.
      Sussenberger et al 98 (1997) evaluated the shear bond strength of light cured
Glass Ionomers with various enamel conditioners like 10% salicylic acid, 10%
benzoic acid, air polishing with sodium hydrogen carbonate followed by
polyacrylic acid, 10% polyacrylic acid, 37% phosphoric acid and one group was
kept as a control without conditioning. The group conditioned with polyacrylic
acid attained the highest mean shear strength of 28 MPa. Conditioning the enamel
surface with the weak organic acid improved the bond strength of Glass Ionomers
and the enamel loss was negligible.
                         53
      Lippitz SJ et al        (1998) compared the shear bond strength of three resin
modified glass ionomer cement (Advance, Fuji Duet, Fuji-Ortho LC) with a
composite resin (Concise) 24 hours and 30 days after debonding. The hybrid with
one exception, had bond strength similar to those of the composite resin at 24
hours and 30 days. Fuji-Ortho-LC had significantly lower bond strength than other
adhesives when it was bonded to unetched, water moistened enamel. Mean shear
bond strength of Fuji Ortho LC at 24 hours was 5.9 MPa and after 30 days was
12.1 MPa whereas others achieved a mean of shear bond strength of around 16
MPa in 24 hours and between 16 – 19 MPa in 30 days.
                         70
      Peter V Flower          (1998) conducted a 12 month clinical trial of comparing
bracket failure rates of LC resin modified glass ionomer adhesive (Fuji–Ortho–LC)
and acid etched chemical cured composite (CONCISE). Failure rates were 6.1%
for Resin Modified Glass Ionomer adhesive and 5.4% for chemical cured
composite, which were not satisfactorily significant. The relative ease of use and
reduced risk of decalcification around brackets were in favour of resin modified
Glass ionomers.
       Immanuel Gillis and Meir Redlich 42 (1998) evaluated the efficacy of three
conditioning techniques with three different adhesives on porcelain brackets. Shear
bond strength of High-Q-Bond was significantly lower than Silane Plus Right–On
and Silane Plus Concise Group. Study revealed that diamond roughening and
micro etching produced only a surface peeling pattern whereas hydrofluoric acid
conditioning produced in depth penetration. However the shear bond strength
achieved by High-Q-Bond was enough to sustain full orthodontic treatment.
       Samir E Bishara et al 86 (1998) compared the shear bond strength following
the use of acidic primers and phosphoric acid with lightly filled adhesive (Clearfil
Liner) and heavily filled adhesive (Panavia -21). Scanning electron microscopic
(SEM) pictures showed thin, uniform resin tags with acidic primers and thick
uniform resin tags following 37% phosphoric acid etching. Results indicated that
clinically optimal shear bond strength was obtained with acidic primer when used
with heavily filled adhesive       (Panavia – 21). The advantage of acid primer was
that it left less adhesive on the tooth.

                                   2
       Ana Rosa Flores et al           (1999) compared the shear bond strength and
debonded enamel surface of photopolymerizable resin modified glass ionomer
cement to etched (Group-2) and unetched enamel (Group-1) with a conventional
light cured composite (Group-3). Scanning electron microscopic (SEM)
photographs showed a porous surface with minimal enamel loss for Group -1. In
Group -2, no change was observed on the enamel surface.           Group-3 showed
greater scratches with evidence of maximum enamel removal. It was concluded
that resin modified glass ionomers (Group-1) had optimal strength with minimal
enamel loss.
                      88
      Sargisson AE         (1999) compared the shear debonding force and mode of
bond failure to sandblasted and acid-etched enamel. The results indicated that 15
seconds etching was clinically significant and at the same time bond strength was
not compromised with minimal enamel loss.
                            18
      Cerehli and Attay          (2000) evaluated the effects of different acid etching
solutions on the etch patterns of human enamel and concluded that regardless of
the treatment time, etching with 37% phosphoric acid resulted in irreversible
damage to enamel surface.
                                       17
      Canay, Kocadereli et al               (2000) found that sandblasting with a micro-
etcher alone resulted in significantly lower bond strength and should not be
advocated for clinical use as an alternative to acid etching.
                                  85
      Samir E Bishara et al            (2000) observed that surface layer of enamel lost
during etching varied between 10 µm and 30 µm, resin tags penetrated upto 50µm
and after debonding and adhesive clean up procedures may remove upto 55.6 µm
of surface enamel.
                                                     110
      Wenedela L, Van Waveran et al                        (2000) quantified the enamel loss
following acid etching and air abrasion and estimated the shear bond strength of
composite (Concise) and glass ionomers (Fuji-Ortho-LC). Sand blasting with a
longer exposure time or high pressure (0.3 MPa) resulted in higher enamel loss.
Pretreatment with aluminium oxide (50µm) sand blaster resulted in significantly
lower bond strength than 37% phosphoric acid etching. Sand blasting obviously
cannot be regarded as an alternative for acid etching.
                                              67
      SE Owens Jr. and BH Miller                   (2000) evaluated the shear bond strength,
site of bond failure of two visible light cured composites (Transbond XT Enlight)
and resin modified glass ionomer cement (Fuji–Ortho LC). Results demonstrated
that light cured composites had a higher shear bond strength than the resin
modified glass ionomer cement. Mean adhesive remnant index scores were two for
the composites which indicated that more than half of the adhesive remained in the
tooth. Fuji Ortho LC had a score of three, which indicated that the entire adhesive
remained on the tooth.
                                                                            27
      Doron Harari, Elias Aunni, Immanuel Gillis, Meir Redlich                   (2000)
evaluated the compatibility of High-Q-Bond adhesive and Right-On adhesive on
etched enamel and roughened old amalgam restorations. Results showed similar
bond strength to enamel. However after debonding, High-Q-Bond left no adhesive
on the enamel. When bonding to amalgam, High-Q-Bond had a significantly higher
shear bond strength than Right-On.
      Shinchi et al 93 (2000) reported that there was no significant difference in the
tensile bond strength of photo – cured resin after pretreating enamel with various
concentrations of phosphoric acid. Scanning electron microscopic (SEM) study
demonstrated that the resin tag depth decreased significantly from 22µm for 35%
phosphoric acid to 5µm for 3% phosphoric acid. It was concluded that length of
resin tags contributed little to the bond strength and the adhesive’s strength was
mainly due to the resins ability to penetrate between enamel crystallites and rods.

                      90
      Sazak H et al        (2001) compared the effects of Nd:YAG laser, air abrasion
and acid etching on human enamel and dentin. Their studies showed that Nd:YAG
laser and air abrasion systems created more surface irregularity in less time than
acid etching when applied to enamel and dentin.
                                  82
      Ross SS, Hobson et al            (2002) evaluated the relationship between acid-
etch pattern and bond survival. Ideal pattern associated with bond strength was
Type A and B.
      A – Well developed conventional etch pattern with well defined prisms.
      B – Prisms apparent but poorly defined.
      C – Pitted enamel surface with no prism definition.
      D – No discernible change in enamel surface (mainly in posterior teeth).
      Decreased bond strength occurred with type C and type B.
                            87
      Samir E Bishara            (2002) compared the effects of time on shear bond
strength of cyanoacrylate system and composite adhesive system. They evaluated
the shear bond strength after half an hour and 24 hours. Bond strength of both the
adhesives did not vary significantly. Both had clinically adequate bond strength.
      Doron Harari et al 28 (2002) studied the shear bond strength of a new dental
adhesive (IntegraCem) which can be used to bond brackets to unetched enamel.
Their results showed that it can be effectively used in orthodontic treatment. Bond
failures occurred at enamel – adhesive interface enabling more efficient enamel
clean up.
      David J. Hegarty and Tatiana V. Macfarlane 84 (2002) – A clinical trial was
performed comparing resin modified glass ionomers with a no-mix resin based
adhesive (control) over a 12-month period. Bracket failure rate was 10% for resin
modified glass ionomers and 4% for resin based adhesive. Resin modified glass
ionomers showed no enamel loss, less enamel demineralization and faster adhesive
removal.

                                      83
      Rudolfo M. Valente et al             (2002) evaluated the tensile bond strength of
resin modified glass ionomers (Fuji – Ortho – LC) using various acid etchants for
enamel preparations. The enamel conditioners were:
            1. 37% phosphoric acid with silica
            2. 37% phosphoric acid (silica free)
            3. 10% phosphoric acid (silica free)
            4. 10% polyacrylic acid
            5. Unetched enamel.
      The different etchants used with resin modified glass ionomers did not affect
the tensile bond strength. Significant lower bond strength were observed when
glass ionomers were bonded to unetched enamel but can bond effectively to etched
enamel in moist environment.
                        92
      Serdar Usumez          (2002) reported that recently introduced Er-Cr: YSGG
hydro - kinetic laser system as an alternative to acid etching. The laser produced
more surface irregularity in lesser time.
                             57
      Mark David Crane            (2003) measured the realiability of orthodontic bond
strength testing. He tested the bonded teeth samples for failure under shear, tensile
and torsional loading. Brackets bonded to teeth and debonded by shear force
exhibited the least variability. He showed that shear testing appears to be the most
consistent method to measure bond strength.
                             1
      Aljubouri YD et al         (2003) compared the mean bonding time, shear bond
strength and survival time of bracket for a self etch primer and a conventional
adhesive system. Mean bonding time and shear bond strength of a self etch primer
was less than two stage bonding of conventional system, whereas the survival time
of brackets were similar for both.

                                                22
      Clark SA, Gorden PH and McCabe                 (2003) assessed the shear peel bond
strength and mode of bond failure for 4-META based adhesive (MCP Bond) and a
composite adhesive (Right On) to acid etched and sand blasted enamel. MCP bond
containing 4-META which is an adhesion promoter seemed to show good shear
bond testing on sand blasted enamel and efficient debonding characters.
      Mavropoulos et al 58 (2003) conducted a clinical evaluation of two moisture
resistant orthodontic adhesive systems (1) special moisture insensitive primer
(Transbond - MIP) (2) a fluoride releasing light cure compomer (Assure). The
results indicated a higher bond failure of 13.8% for fluoride releasing LC
compomer and 7.3% for moisture in sensitive time primer.
                                    106
      Vittorio Cacciafesta et al          (2003) evaluated the effects of 3 different
enamel conditioners (10% polyacrylic acid, 37% phosphoric acid and self etching
primer) on the shear bond strength and site of bond failure of resin modified glass
ionomers (Fuji – Ortho – LC) bonded onto dry, water moistened and saliva
moistened enamel. Fuji- Ortho- LC produced the highest shear bond strength
under all circumstances with self etching primer, except when Fuji Ortho LC was
used in combination with 37% phosphoric acid on dry enamel.
                               4
      Andrew summers et al         (2004) found no significant invivo survival rates
between resin modified glass ionomer (Fuji-ortho-LC) and conventional adhesive
(Light bond) which were followed for 1.3 years. The invitro study showed
increased bond strength for conventional resin (18.46 ± 2.95 MPa) against 9.56 ±
1.85 MPa for resin – modified glass ionomer. Scanning electron microscopic
(SEM) study of 10% polyacryclic acid conditioned enamel surface prior to resin
reinforced glass ionomer revealed minimal surface irregularities with smooth
precipitates in some areas. 37% phosphoric acid etched enamel exhibited rough
and a porous surface with dissolution of prism cores. It was concluded that Fuji –
Ortho-LC had adequate bond strength to withstand occlusal stresses.

                              84
      Samir E Bishara et al        (2004) evaluated the shear bond strength of two
self etch primer / adhesive systems in which one self etch primer adhesive system
was supplied as two components that has to be mixed (Transbond Plus – 3m
Unitek). The other was a no mix adhesive system (Ideal-1: GAC International).
The shear bond strength of new Ideal -1 component (no mix) self etch primer
performed well, as the two component system but saved a step in bonding
procedure.
                                 102
      Timothy Swanson et al            (2004) Shear bond strength of orthodontic
brackets bonded with light emitting diodes (LEDs) were found to be greater than 8
MPa even with 10 seconds cure. They are capable of delivering higher intensities,
thereby reducing the polymerization time. Transbond self etching primer was used
along with Adhesive Pre Coated (APC) brackets.
      Maria Francesca et al56 (2004) assessed the effect of blood contamination
on shear bond strength and bond failure site of conventional primer (Transbond
XT) and self etching primer (Transbond Plus) on adhesive precoated (APC)
brackets.     Non contaminated enamel had the highest bond strengths for both
conventional and self etching primer. Blood contaminated conditioners reduced the
bond strength considerably to such an extent that it became clinically inadequate.
Bond failure occurred at the enamel adhesive interface in blood contaminated
conditions.
                               101
      Theodore Eliades et al         (2004) evaluated the enamel surface roughness
following debonding by using two grinding methods (i.e.) eight bladed carbide bur
and ultra fine diamond bur. No significant difference was noted in the enamel
surface but resin removal with diamond bur required only half the time as that
required by the carbide bur.

                 SUMMARY AND CONCLUSION
      The present study was undertaken to evaluate and to compare the shear bond
strength of IntegraCem – a fourth generation dentin bonding agent on unetched
enamel with an already established resin modified glass ionomer - Fuji Ortho LC
and to determine the mode of bond failure.
      The samples for the study consisted of 75 premolar teeth, which were
mounted on coloured acrylic blocks and divided into 5 equal groups of 15 each.
Group I :     IntegraCem and Integrabond were used with stainless steel
              brackets and bonded to unetched enamel.


Group II:     IntegraCem and Integrabond were used with stainless steel
              brackets and bonded to unetched enamel. The samples were
              later thermocycled in Fisons’s Climatic Chamber from 6oc
              to 60oc for 2500 cycles.
Group III: IntegraCem and Integrabond were used with ceramic
              brackets and bonded to unetched enamel.
Group IV: Fuji Ortho LC was used with stainless steel brackets and
              bonded to unetched enamel.
Group V:      Acid etching was done with 37% phosphoric acid for 15
              seconds. Stainless steel brackets were bonded with
              IntegraCem to the etched enamel surface.
        Universal Testing Machine – INSTRON was used in the study, to record the
shear bond strength. After debonding, the bond – failure interface of the samples
were examined under the STEREOMICROSCOPE and ARI scores were tabulated.
The results were subjected to statistical analysis. The debonded enamel surface of
three    samples   were    examined      under   the   SCANNING      ELECTRON
MICROSCOPE.
The following inferences were made from the study
   Adequate shear bond strength for orthodontic purposes was achieved when
   stainless steel or ceramic brackets were bonded with IntegraCem to unetched
   enamel.
   When the samples were thermocycled, the shear bond strength got reduced
   considerably, but was still within the optimal range.
     When compared with the already established Fuji – Ortho LC on unetched
     enamel, IntegraCem had higher bond strength values.
     The bond failure was located at the Enamel – Adhesive Interface for the
     unetched groups, thereby leaving minimal or no residual adhesive on the
     debonded enamel surface.
     The bond failure was located at the Bracket - Adhesive interface for the etched
     groups.
     The SEM study of the debonded enamel surface of unetched IntegraCem
     revealed minimal surface irregularities whereas the etched group revealed the
     entire adhesive to be remaining on the debonded enamel surface.
The advantages of bonding IntegraCem on unetched enamel were:
     1. Eliminated the enamel loss following acid etching.
     2. Total removal of the resin during debonding left the enamel free from any
        iatrogenic damage.
     3. Prevented the discolouration of enamel due to retention of resin tags
        following etching.
     4. Permitted easier debonding of ceramic brackets without any undue effects
        on enamel.
     5. Saved significant chair-side time, as etching and rinsing were eliminated.
               On the basis of this invitro evaluation, it may be concluded that,
        IntegraCem can be used to bond both stainless steel and ceramic brackets to
        unetched enamel, but invivo tests should be performed before introducing
        IntegraCem into routine clinical practice.
                              BIBLIOGRAPHY

1.    Aljubouri YD, Millet DT and Gilmour WH : Laboratory evaluation of a self –
      etching primer for orthodontic bonding. Eur J Orthod 2003: 25; 411 – 415.
2.   Ana Rosa Flores, Gebrial Saz E, Federico Barulo : Metallic bracket to
     enamel bonding with a photo – polymerizable resin reinforced glass ionomer.
     Am J Orthod & Dentofac Orthop 1999; 116: 514 – 517.
3.   Andreas Karamouzous, Athanasiou, Dent and Papdoupoulos : Clinical
     Characteristics and Properties of ceramic brackets: A Comprehensive review.
     Am J Orthod and Dentofac Orthop 1997 ; 112; 3 4 – 40.
4.   Andrew Summers, Elizabeth Kao, Jefrey Hilman: Comparison of bond –
     strength between conventional resin adhesive and resin modified glass
     ionomer cement – An invitro and invivo study. Am J Orthod & Dentofac
     Orthop 2004; 126: 200 – 6.
5.   Anne M. Compton, Charles E. Meyers, Steven O. Humdrum.: Comparison of
     shear bond strength of a light cured glass ionomer and a chemically cured
     glass ionomer for use as an orthodontic bonding agent. Am J Orthod &
     Dentofac Orthop 1992.
6.   Artun J. and Bergland. S.: Clinical trials with crystal growth conditioning as
     an alternative to acid etch enamel pre-treatment.
     Am. J. Orthod 1984 : 84; 333 – 340.
7.   Bark Meirer W., Guinnett A. J. and Schaffer S.E.: Effects of enamel etching
     on bond strength and morphology. J. Clin. Orthod – 1985; 19: 36 – 38.
8.   Bowen RL., Eichmiller F.C, Marjenhoff W.A. and Rupp N.W.: Adhesive
     bonding of composites. J. Am. Coll. Dent 1989; 56 : 10.
9.   Brauer G.M. and Termini D.J.: Bonding of bovine enamel to restorative
     resin. Effect of pre – treatment of enamel. Journal of Dental Research 1972;
     51: 151 – 160.
10. Bronwen Vorhies.A, Kevin J. Donly, Robert N. Staley & James S.: Enamel
    demineralization adjacent to orthodontic brackets bonded with hybrid GIC –
    An invitro study. Am.J. Orthod & Dentofac Orthop 1998; 114: 668 – 74.
11. Brown WS. Jacobs HR, Thompson RE. Thermal fatigue in teeth.                  J.
    Dent Res 1972; 51; 461 – 7.
12. Bryant S. Retief. H., Carl M. Russell., Denys. E.R.: Tensile bond strength of
    orthodontic bonding resins and attachment to etched enamel. Am J Orthod
    1987; 92: 225 – 31.
13. Buonocore M.G., Gwinett A.I.: Penetration of resin dental materials into the
    enamel surface with reference to bonding. Archives of Oral Biol 1968; 13: 16
    – 70.
14. Buonocore M.G.: A Simple method of increasing the adhesion of acrylic
    filling materials to enamel surface J.Dent Res.1955; 34:849 – 53.
15. Buzzita, Hallgren and Powers. : Bond strength of orthodontic direct bonding
    cement and bracket system. Am. J. Orthod 1982 ; 81 : 87 – 92.
16. Cadwell D.E. and Johannessen B. : Adhesion of restorative materials to teeth.
    J. Dent Res. 1971: 50: 1517 – 1525.
17. Canay S, Kocadereli I and Akea E. : The effect of enamel air abrasion and
    retention of bonded metallic orthodontic brackets. Angle Orthod 2000; 69:
    351 – 356.
18. Cerehli C, Altay.: Effect of a non-rinse conditioner and 17% EDTA on the
    etch pattern of intact human permanent enamel. Angle Orthod    2000; 70:
    22 – 27.
19. Charuphan Oonsomtat, Samir Bishara, Raed, Ajlouni.: The effect of blood
    contamination on shear bond strength of orthodontic brackets with a use of a
    new self etch primer. Am J Orthod and Dentofac Orthop 2003; 123: 547 – 50.
20. Ching Hiang Meng, Wei Nan Wang, Sung Yeh. : Fluoridated etching on
    orthodontic bonding. Am J Orthod and Dentofac Orthop 1997;112: 259– 62.
21. Chung Hsi Chung, Blair W. Faden, Hawey Lerit, Francis Mente:. Effects
    of two adhesive boosters on shear bond strength of new and rebonded
    orthodontic brackets. Am J Orthod and Dentofac Orthop 2000; 118; 295 –
    299.
22. Clark SA, Gordon PH, McCabe JF.: An exvivo investigation to compare
    orthodontic bonding using 4 - META based adhesive on a composite adhesive
    to acid etched and sand blasted enamel. J. of Orthod. 2003; 30: 51 – 58.
23. Cook PA. : Direct bonding with glass ionomer cement. J. Clin Orthod. 1990;
    24: 509 – 511.
24. David J. Hegarty, Tatiana V, Mactarlane. : Invivo bracket retention -
    Comparison of resin modified glass ionomer cement (RMGIC) and a resin
    based bracket adhesive system after a year. Am J Orthod and Dentofac Orthop
    2002; 121: 496 – 501.
25. Der Horng Sheen.: Bond strength of young and older permanent teeth with
    various etching times. Angle Orthod 1992; 63: 225 – 230.
26. Diedrich P.: Enamel alterations from bracket bonding and debonding – A
    Scanning Electron Microscopic study. Am J Orthod and Dentofac Orthop
    1989; 79: 500 – 22.
27. Doron Harari, Elias Aunni, Immanuel Gillis, Meir Redlich.: A new
    multipurpose dental adhesive for orthodontic use – An invitro bond strength
    study. Am J Orthod Dentofac & Orthop 2000;118:307 – 10.
28. Doron Harari, Immanuel Gillis, Meir Redlich.: Shear bond strength of a
    new dental adhesive used to bond brackets to unetched enamel. Eur J. Orthod
    2002; 24; 519 – 23.
29. Elham S, Abu Alhaju and Ahed M.S. Wahadin.: Evaluation of shear bond
    strength with different enamel pre – treatment. Eur J. Orthod – 2004; 26: 179
    – 184.
30. Eliades T, Eliades G, Brantley W.A, Johnston W.M.: Residual monomer
    leaching from chemically cured and visible light cured orthodontic adhesives.
    Am J Orthod and Dentofac Orthop 1995; 108: 316 – 21.
31. Elliot Silverman, Mortan Cohen, Richard S Demake.: A new light cured GIC
    that bonds brackets to teeth without etching in the presence of saliva. Am J
    Orthod & Dentofac Orthop 1995; 108: 231 – 236.
32. Evans & Powers.: Invitro bond strength of no mix orthodontic cements.Am J
    Orthod 1985; 86: 508 – 512.
33. Eversol D.K, Moore R.N.: Bonding orthodontic acrylic resin to enamel.Am J
    Orthod and Dentofac Orthop 1988; 93: 477 – 485.
34. Farquachar R.B.: Direct bonding comparing a polyacrylic acid and a
    phosphoric acid technique. Am J Orthod 1986; 90: 187 – 194.
35. Fritz, Finger, Uno.: Resin modified glass ionomer cements and their bond
    strength. Dent. Material 1996; 12 (1): 161 – 166.
36. Gale M.S, Darvell B.W.: Thermocycling procedures for laboratory testing of
    dental restorations. Journal of Dentistry 1999; 27: 89 – 99.
37. George V. Newman, Richard A. Newman, Ajit K. Sengupta.: Comparative
    assessment of light cured resin modified glass ionomer and composite resin
    adhesive. An invitro study of a new adhesive system.        Am J Orthod
    &Dentofac Orthop 2001 – 119: 256 – 262.
38. Gorden V.V, Vargas M.A., Cobb D.S.: Effectiveness of acidic primers with
    and without etching in the adhesion to enamel and dentin. J. Dent Res. 1997;
    76 : 408.
39. Gwinett A.J.: Histological changes in human enamel following treatment with
    acidic adhesive conditioning agents. Archives of Oral Biology 1971; 12: 1615
    – 1620.
40. Hitt J. and Fregal R.J.: Use of bonding agent to reduce sealent sensitivities to
    moisture contamination – An Invitro study. Journal of Pediatric Dentistry
    1992 ; 14: 14 – 46.
41. Hormati A.A, Fuller I.L, Denely G.E.: Effects of contamination and
    mechanical disturbance on the quality of acid – etched enamel. Journal of
    America Dental Association 1980; 100: 34 – 38.
42. Immanuel Gillis and Meir Redlich.: The Effect of different porcelain
    conditioning techniques on shear bond strength of stainless steel brackets. Am
    J Orthod and Dentofac Orthop 1998; 114: 387 – 92.
43. Jassem and Retief.: Tensile and shear strength of bonded and rebonded
    orthodontic attachment. Am J Orthod 1981; 79: 661 – 68.
44. Jefferey W. James, Barbara H. Miller, Jeryl Eafise, Larry P. Jadlock and
    Peter H. Buscharg.: Effect of high speed cutting devices on shear bond
    strength and microleakage of orthodontic brackets. Am J Orthod and Dentofac
    Orthop 2003; 123 : 555 – 562.
45. John. P. Fircker.: A twelve month clinical evaluation of a glass polyalkeonate
    cement for direct bonding of orthodontic bracket. Am J Orthod and Dentofac
    Orthop 1992: 101; 381 – 84.
46. Jose Augusto Mendes Migeul, Marc Antonio Almedia, Oriando
    Cheritarese.: Clinical comparison between GIC and a composite for direct
    bonding of orthodontic brackets. Am J Orthod and Dentofac Orthop 1995.
47. Kaizere S., Tencate J.M., Arends J.: Direct bonding of orthodontic brackets
    Am J Orthod 1976; 69: 328 – 337.
48. Krejei I, Lutz E. Mixed class V restoration – the potential of a dentin
    bonding agent J. Dent : 1990: 18; 263 – 270.
49. Krishnan P.H., Taylor and Arend.: Direct bonding of orthodontic brackets.
    Am J Orthod 1976; 69:318 – 327.
50. Larmour C.J. and Stirups D.R.: An exvivo assessment of a bonding
    technique using self– etching primer. J of Orthod.-2003; 30: 225 – 28.
51. Larry J. Oesteile, Craig Shellhart W.: Bracket Bond strength with trans-
    illumination of a light activated orthodontic adhesive. Angle Orthod 2001; 71:
    307 – 311.
52. Lawrence R. Gerbo, William R. Zace Field, Bobby R. Wells, Carl M.
    Russell.: The effect of enamel preparation on the tensile bond strength of
    orthodontic composite resin. Angle Orthod 1992; 4: 57 – 62.
53. Lippitz S.J., Staley R.N. Jakobsen J.R.: Invitro study of 24 hour and 30 day
    shear bond strength of three resin modified – GIC used to bond orthodontic
    brackets. Am J Orthod & Dentofac Orthop 1998;113:620-4.
54. Maijer – R, Smith D.C.: A new surface treatment for bonding. J. Biomed
    Matter Res 1979; 13: 975 – 85.
55. Maijer R, Smith DC.: Crystal growth on the outer enamel surface – An
    alternative to acid etching. Am J Orthod – 1986; 89: 183.
56. Maria Frances Ca Sfondrini, Vittoria Cacciafesta, Andrea Scribante,
    Marco-De-Angels and Catherine Klessy.: Effect of blood contamination on
    shear bond strength of brackets bonded with conventional and self etching
    primer. Am J Orthod and Dentofac Orthop 2004; 125: 357 – 360.
57. Mark David Crane: Reliability of orthodontic bond strength testing. Am J
    Orthod and Dentofac Orthop 2003; 124: 100 -101.
58. Marropoulos A., Karamouzos. A, Kolokithas Athanasious.: Invivo evaluation
    of two new moisture resistant orthodontic adhesive system – a comparative
    clinical trial. J of Orthod – 2003; 30: 139 – 147.
59. Martin Branstrom., Kail Johan Nordenvali. : The effect of acid etching on
    enamel dentin and the inner surface of the resin restoration. A SEM
    investigation. J. Dent Res. 1977; 56: 917 – 923.
60. Millet D.T: Laboratory evaluation of a compomer and resin modified GIC for
    orthodontic bonding. Angle Orthop 1999; 69: 1.
61. Moin Dogon IL.: Indirect bonding of orthodontic attachments. Am J Orthod
    1977; 72: 261 – 274.
62. Neme and Kohn: Evaluation of bond strength to amalgam and composite to
    tooth structure using seven adhesive system. J. dent. Res. 1977; 76: 432.
63. Newman G.V. : Epoxy adhesives for orthodontic attachments – A progress
    report. Am J Orthod Dentofac Orthop 1965; 51: 901 – 72.
64. Nordenrall K.J. Brannstrom M., Malmgreno: Etching of deciduous teeth,
    young and old permanent teeth. Am J Orthod 1980; 78: 99 – 108.
65. Ortendahl T.N. and Ortengren W. : A new orthodontic bonding adhesive. J.
    Clin. Orthod. 2000; 50 – 54.
66. Oslen M.I., Bishara S.E, Damen P. : Evaluation of scotch bond multipurpose
    and maleic acid as an alternative methods of bonding orthodontic brackets. Am
    J Orthod and Dentofac Orthop 1997; 111(5); 498 – 501.
67. Owen S.E., Miller B.H., : A comparison of shear bond strength of visible light
    cured orthodontic adhesives. Angle Orthod 2000; 70 (5).
68. Paul Alexander Young, Sandrik and Bowman. : Bond strength of three
    orthodontic adhesives. Am J Orthod 1981; 79: 653 – 660.
69. Paul Surmont, Luc Dermant, Luc Martens and Michael Moors.: Comparison
    of shear bond strength of an orthodontic bracket between five bonding systems
    related to different etching times – An invitro study.      Am J Orthod and
    Dentofac Orthop 1922; 105 (5): 414 – 419.
70. Peter V. Fowler : A twelve month clinical trial comparing the bracket failure
    rates of light cured resin – modified GI adhesive and acid – etch chemical
    cured composite. Aust. J. Orthod 1998 ; 15 : 186 – 190.
71. Peterson EA, Philips RW, Swartz ML. : A comparison of the physical
    properties of 4 restorative resins. J. Am Dent Assoc 1996: 73: 1324 – 36.
72. Pramod K. Sinha, Rama Nandha, Manville G, Duncanson, Michael J.
    Hosier : Invitro evaluation of matrix bound fluoride releasing orthodontic
    bonding adhesive. Am J Orthod and Dentofac Orthop 1997; 111: 276 – 282.
73. Pretorius L.M. Duplessis L.S.: Comparison of etch efficacy of pyruvic acid
    and phosphoric acid. J. Dent Res. 1988; 67 : 776 – 780.
74. Ram Kumar Grandhi, Edward Charles Cambe, Thomas Micheal Speidel.:
    Shear bond strength of stainless steel orthodontic brackets with moisture
    insensitive primer. Am J Orthod and Dentofac Orthop 2001; 119: 251 – 255.
75. Rangaswamy Rajagopal, Sridevi, Janakirama Gnanamani.: A Comparison
    of shear bond strength and debonding characteristics of Conventional,
    Moisture insensitive primer (MIP), Self etching primer (SEP). An invitro
    study. Angle Orthod – 2004; 74: 264 – 268.
76. Rashid Ahmed Chamda; Errol Stein.: Time related bond strength of light
    cured and chemically cured bonding system. An invitro study. Am J Orthod
    and Dentofac Orthop 1996; 110: 378 – 382.
77. Reads K.D, O’Brien, Sandison R.J.: A visible light activated direct bonding
    material – An invivo comparitive study. Am J Orthod and Dentofac Orthop
    1989; 95: 348 – 351.
78. Redlich M, Hararay D, Shoshan S.: Gingival response to a new multipurpose
    dental adhesive. A histological study in dogs. J. Prosth Dent 1996; 76: 379 –
    85.
79. Reynolds I.R : A review of direct orthodontic bonding : An invitro study Br. J
    Orthod. 1975; 2: 171 – 178.
80. Rezk Hega and Ogaard.: Tensile bond strength of brackets bonded with Glass
    Ionomers Cement. Angle Orthod 1979; 119: 1 – 10.
81. Rod Green Law, David C. Way, Khadry A. Galil : An invitro evaluation of a
    visible light cured resin as an alternative to conventional resin bonding
    systems. Am J Orthod & Dentofac Orthop 1989; 96: 214 – 220.
82. Ross. S. Hobson: The relationship between acid etch pattern and bond
    survival invivo. Am J Orthod & Dentofac Orthop 2002; 121: 502 – 526.
83. Rudolfo M . Valente, Waldemar G. de Rijk James L, Drummond and Carla
    A. Evans : Etching conditions for resin modified glass ionomer cement (Fuji
    Ortho LC) for orthodontic brackets. Am J Orthod and Dentofac Orthop 2002;
    121: 516 – 521.
84. Samir E. Bishara, Charupan Oonsomtat, Raed Ailounisa, John F. Laffoon.:
    Comparison of shear bond strength of two self – etch primer adhesive systems.
    Am J Orthod & Dentofac Orthop 2004; 125:348 – 50.
85. Samir E. Bishara, Leigh Vonwald, John F. Laffon and Jane R. Jakobsen.:
    Effects of Changing enamel conditioner concentration on shear bond strength
    of a resin modified glass ionomer (RMGIC) adhesive. Am J Orthod and
    Dentofac Orthop 2000; 118: 311 – 16.
86. Samir E. Bishara, Valeria V. Gordon, Leigh Von Wald Marc E. Olson.:
    Effect of acidic primer on shear bond strength of Orthodontic Bracket. Am J
    Orthod and Dentofac Orthop 1998; 114 : 243 – 7.
87. Samir E. Bishara.: Effect of time on shear bond strength of cyanoacrylate and
    composite orthodontic adhesive. Am J Orthod and Dentofac Orthop 2002; 121
    : 297 – 300.
88. Sargisson and Mc Cabe.: A laboratory investigation to compare enamel
    preparation by sand – blasting or acid etching prior to bracket bonding. J of
    Orthod – 1999; 26 (2); 141 – 146.
89. Sargisson E., John F. McCabe., Peter H. Gordon.: An Exvivo study of self,
    light and dual cured composites for orthodontic bonding. J of Orthod – 1994;
    22(4) : 319 – 323.
90. Sazak. H., Turkmen. C., Gunday H.: Effect of Nd – YAG laser, air – abrasion
    and acid etching on human enamel and dentin. Oper dent 2001; 26: 476 – 481.
91. Sejal B. Jobalia, Rudolfo M. Valente, Waldemar Ellen A. Begole and Carlo
    A. Evans.: Bond strength of visible light cured glass ionomer orthodontic
    cement. Am J Orthod & Dentofac Orthop 1997;112:205 – 8.
92. Serdar Usumez, Metin Orhan, Aslihan Usumez.: Laser etching of enamel for
    direct bonding with Er, Cr: YSGG hydrokinetic laser system. Am J Orthod
    and Dentofac Orthop 2002; 122: 649 – 56.
93. Shinchi M.J, Soma K, Nakabayashi. N.: The effect of phosphoric acid
    concentration on resin tag length and bond strength of a photocured resin to
    acid – etched enamel. Dental Materials 2000; 16: 324 – 329.
94. Silver Stone: An invivo study of enamel after etching with different
    concentrations. J. Dent Res – 1974. ; 52: 967 – 68.
95. Smith DC and Maijer R. Improvement in bracket base design, Am J. Orthod
    1983 : 83 : 277 – 81.
96. Smith G.A., Ledoux P.M. Ledoux W.R., Roger Weinburg.: Orthodontic
    bonding to porcelain – Bond strength and refinishing. Am J Orthod &
    Dentofac Orthop 1988; 94: 245 – 52.
97. Smith R.T. Shiva Priya P.K.: The Evaluation of dual cement resins in
    orthodontic bonding Am J Orthod & Dentofac Orthop 1993;103:448 – 51.
98. Sussenberger. U., Cacciafesta. V, Jost P.G. Brinkman.: Lightcured GIC as a
    bracket adhesive with different types of enamel conditioners. Journal of
    Orofacial orthopedics 1997; 58: 174 – 80.
99. Swartz MI : Ceramic brackets. J. Clin Orthod 1988; 22; 83 - 88.
100. Tawas and Watts: Bonding of othodontic brackets by transillumination of
     light activated composite – An invitro study. Br J Orthod – 1979; 6: 207 –
     208.
101. Theodore Eliades, Christiana Gioka, George Eliades: Enamel Surface
     following debonding using two resin grinding methods. Eur. J Orthod 2004;
     26; 333 – 338.
102. Timothy Swanson, William J. Dunn, Darrel E.Childers and Louis J.
    Taloumis. Shear bond strength of orthodontic bracket bonded with light
    emitting diode (LED) curing units at various polymerization times. Am J
    Orthod and Dentofac Orthop 2004; 125: 337 – 341.
103. Todd Kimura, William J. Dunn, Louis J. Tolenis: Effect of Fluoride Varnish
     on invitro bond strength of orthodontic bracket using self – etching primer
     system. Am J Orthod and Dentofac Orthop – 2004; 125 : 311 - 356.
104. Tole M Dano, Raquel Osorio, Estrella Osoria. Alejandro Romeo, Blanca de
     la Higuera, Franklin Garlia – Godoy. : Bond strength of orthodontic bracket
     using different light and self – curing cements. Angle Orthod – 2003; 73: 56 –
     63.
105. Triolo P.T.: Effects of etching time on enamel bond strength. Am J Orthod
     and Dentofac Orthop. 1993; 18 302 – 304.
106. Vittorio Cacciafesta. Maria Francesca, Lucia Baluga, Andrea Scribante
     Catherine Klersy: Use of self etching primer in combination with a resin –
     modified glass – ionomer. Effect of water and saliva contamination on shear
     bond strength. Am J Orthod and Dentofac Orthop – 2003; 124: 420 – 26.
107. Wasundhara. A, Bhad and Pushpha V. Hazarer.: Scanning Electron
     Microscopic (SEM) study and shear bond strength measured with 5% and
     37% phosphoric acid. Am J Orthod and Dentofac Orthop 1995; 108: 410-
     414.
108. Wei and Lee.: Electron Microprobe analysis of re-mineralisation of enamel.
     Journal of dental research 1971; 49: 621 – 625.
109. Wei Nanwang and Tzchan L.V.: Bond strength with various etching times on
     young permanent teeth. Am J Orthod and Dentofac Orthop 1991; 72 – 79.
110. Wendela L. Van Waveran Hogervorst, Albert J. Feilzer, Birte Prahl –
     Andersen.: The air abrasion technique versus the conventional acid – etching
     technique. A quantification of enamel loss and a comparison of shear bond
     strength. Am J Orthod & Dentofac Orthop 2000; 117:20 – 26.
111. White L.W.: Glass ionomer cement. J Clin Orthod– 1986: 20; 387 – 391
112. Wright AB, Leek T, Lynen E, Young KA : Clincal and microbiological
     evaluation of resin modified GIC for orthodontic bonding. Am J Orthod &
     Dentofac Orthop 1996; 110:469 – 75.
113. William A. Witlshire: Shear bond strength of a glass ionomer for direct
     bonding in orthodontics. Am J Orthod and Dentofac Orthop 1994; 106: 127 –
     130.
114. Yamada T, Smith D.C. Maijer R. Tensile and shear bond strength of
     orthodontic direct bonding adhesive. Dental Materials 1988;4:243 – 250.
115. Zachrisson Y.O. Zachrisson B.U. Buyukyilmaz. T.: Surface preparation for
     orthodontic bonding to porcelain. Am J Orthod and Dentofac Orthop 1996;
     106: 420 – 43.
116. Zarrinnia.K, Kehoe.MJ : The effect of different debonding techniques on the
     enamel surface. An invitro qualitative study. Am J Orthod Dentofac orthop
     1995; 108 : 284 - 93

								
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