Docstoc

dvc

Document Sample
dvc Powered By Docstoc
					DENT 430, eportfolio Assignemt #4, DBV prep/resto, J. Ghahremani




     Direct Bond Veneer
    Preparation and Restoration

                                      Javiid Ghahremanii
                                      Jav d Ghahreman
                                              DMD 2010
                                              DMD 2010

                                      UBC Faculltty off Denttiisttrry
                                      UBC Facu y o Den s y




1
DENT 430, eportfolio Assignemt #4, DBV prep/resto, J. Ghahremani




Introduction

    Composite veneers can be used to correct size, shape, color and surface texture of the tooth.

Direct composite veneers have advantages over indirect ceramic veneers. These advantages include

reparability, one visit appointment, less cost and more conservation (Roberson, Heymann, & Swift

2006). However, maintaining the esthetic appearance of direct restorations is not as good as indirect

porcelain veneers (Summit, Robbins, Hilton, & Schwartz, 2006). To achieve optimal esthetic results,

case selection, material selection and meticulous attention to details in preparation and restoration

are crucial.




2
DENT 430, eportfolio Assignemt #4, DBV prep/resto, J. Ghahremani




                              Preparation




1. facial tooth reduction:( 0.3 mm at gingival to 0.5 mm at mid body)

Tooth and material considerations:

     Preservation of the health of the pulp and the integrity of the tooth structure are the primary

objectives during operative procedures. Conservative intra-enamel preparation is indicated to

3
 DENT 430, eportfolio Assignemt #4, DBV prep/resto, J. Ghahremani

 achieve more esthetic, sound physiologic and better-bonded restoration by removing superficial

 fluoride rich layer of the enamel (Summit, Robbins, Hilton, & Schwartz, 2006). Various depth of

 facial reduction is indicated to provide a balance between thickness of the enamel and adequate

 thickness of composite required for esthetic.

  Since the preparation should be ended in the enamel for better and reliable bonding to the tooth

 structure and preventing microleakage, the depth of the preparation is dependent on the enamel

 thickness. Average thickness of the enamel is 0.3-0.5 mm in gingival third, 0.6-1.0 mm in middle and

 1.2-2 mm in incisal area (Ferrari et al, 1992), therefore the depth of the preparation should be less in

 the gingival third (0.3 mm) compare to the middle third (0.5 mm). By creating more space for

 composite in the middle and especially in the incisal third, the esthetic result of the final

 restoration will be significantly improved.



                                  Different facial tooth reduction




0.3 mm                                                                                             0.5 mm




 4
DENT 430, eportfolio Assignemt #4, DBV prep/resto, J. Ghahremani




How to do that:

     To create a chamfer margin, it is better to use a chamfer bur. To be sure about the correct

reduction, it is better to use a chamfer bur with proper thickness and confirm it by measuring its

diameter from tip to the base. By using a chamfer bur with 1mm diameter at the tip, the reduction

will be half of its diameter at the mid-facial part and one third at the gingival. I found that by

cutting half of the facial surface first, mesial or distal, the unprepared part could be used as a guide

to prepare the surface in such a way that follows the profile of the tooth. The final preparation

should have three different planes from gingival to incisal when looking from proximal, following

outer contour of the tooth. Using mirror and looking at the preparation from the proximal are very

helpful.



2. Incisal chamfer:

Tooth and material considerations:

    Meanwhile incisal chamfer exposes enamel rods and provides adequate space for the

composite; it eliminates unnecessary removing of the incisal edge. Preparing a chamfer at the

incisal margin will preserve palatal half of the incisal edge, which can protect the restoration from

occlusal forces especially during lateral and protrusive excursions (Roberson, Heymann, & Swift

2006).




5
DENT 430, eportfolio Assignemt #4, DBV prep/resto, J. Ghahremani




                     Incisal chamfer




How to do that:

    By using tip of the chamfer bur and moving it mesio-distally while the bur is parallel to the long

axis of the tooth.


3. Dog leg into the embrasure:
Tooth and material considerations:

    The purpose of the dog leg preparation into the embrasures is to hide margins of the

restoration in invisible areas for two different reasons: If the purpose of the veneer is to change the

6
DENT 430, eportfolio Assignemt #4, DBV prep/resto, J. Ghahremani

color of the tooth, dog leg hides the margin between two different colors of the tooth and the

restoration. The other reason is to hide the possible margin discoloration of the restoration as time

passes.




            Dog leg preparation




How to do that:

    By using narrow chamfer bur to prevent nicking the adjacent tooth. To avoid over preparation

in interproximal areas (hourglass shape), bur should move in sweeping motion and parallel to the

proximal surface and removing even thickness of the enamel.




7
DENT 430, eportfolio Assignemt #4, DBV prep/resto, J. Ghahremani

4. Exactly to the proximal contact but not through it (no untouched tooth
should be visible):

Tooth and material considerations:

       Preserving proximal contacts conserves tooth structure and integrity. Moreover, when

tooth structures are in contact in proximal areas, instead of composite and adjacent tooth, the risk

of proximal attrition will be considerably reduced. Proximal attrition (which occurs at contact areas)

can cause a reduction of the dental arch (Grippo , J.O., Simring, M., Schreiner, S. 2004)




                              Preserved proximal contact area




How to do that:

    By determining the proximal contact areas first and trying to preserve them by using tip of the

narrow chamfer bur cautiously.


8
DENT 430, eportfolio Assignemt #4, DBV prep/resto, J. Ghahremani

5. Smooth labial surface:

Tooth and material considerations:

    In this way composite will adapt better to the tooth surface and adhesion will be improved.

Furthermore, preparing facial surface in five different planes from mesial to distal insures that the

even amount of tooth structure is removed and therefore even thickness of composite will be

placed which helps to achieve better esthetic results.




                                Uniform space for composite




How to do that:

    By using fine diamond chamfer bur and in lower speed than usual preparation for better control

of the instrument.



9
DENT 430, eportfolio Assignemt #4, DBV prep/resto, J. Ghahremani




6. Line angles should be in ideal position (i.e. as on original labial
surface):

Tooth and material considerations:
     Unless we want to change the position of the facial line angles to create scotoma or illusion,

the goal is to recreate the original location of them. For this reason and to have uniform thickness

of the composite, facial line angles should be placed in their original position.



                                 Position of the original tooth
                                  & preparation line angles




How to do that:

     By looking at the original contour of the facial surface from incisal view first and then during

preparation by considering the adjacent tooth anatomy as a guide.



10
DENT 430, eportfolio Assignemt #4, DBV prep/resto, J. Ghahremani



7. Atraumatic gingival management:
     To prevent any bleeding that can jeopardize bonding process, gingival tissue should not be

traumatized during preparation or restoration by any reason including using 212 retainer or

touching gingival tissue by the bur.


How to do that:

 By avoiding the using of retainer on that particular tooth. To prevent gingival laceration
throughout preparation, pulling the dam away from the tooth and looking at the gingival crest,
especially during margin preparation, are very helpful.


8. Extension of the preparation exactly to the gingival crest:
Tooth and material considerations:

 To finish the gingival margin on the sound enamel, for reliable bonding and hiding gingival margin

of the restoration, this margin is made equigingival.




                                    Equigingival chamfer margin




11
DENT 430, eportfolio Assignemt #4, DBV prep/resto, J. Ghahremani




How to do that:

     By considering gingival crest during preparation. For better control of the preparation, it is

better to pull the dam away from the tooth during the placement of the gingival margin.




                                  Restoration




1. No monochromatic:

Tooth and material consideration:

For appearance reconstruction of an anterior tooth, all of the elements of the esthetic should be

provided, including color, in such a way that it can mimic the expression of a natural tooth
12
       DENT 430, eportfolio Assignemt #4, DBV prep/resto, J. Ghahremani

       (Goldstien R.E , 1998). Natural teeth are polychromatic with transition from a darker and more

       saturated color in the gingival area to a lighter and more translucent color toward the middle and

       incisal area. Furthermore, by moving from proximal area to the mid-facial region, tooth

       translucency will decreased. By reproduction of the color, restoration will blend with surrounding

       structures and will look more natural.

             B3

              B2

              B1

     Translucent



Different layers of the composite




                                                                                  Gradient of translucency from
                                                                                        gingival to incisal
       How to do that:

       There are different ways for color selection but to achieve the best result, basic rules should be

       followed. Some of these rules consist of: color selection before preparation and tooth desiccation,

       using shade guide just as a “guide” and using selected colors on unprepared tooth surface with

       desired thickness before preparation to confirm the selection. In this case, I used B3 for the

       gingival, B2 for middle and B1 for incisal third. For the incisal and half of the middle third, I overlaid

       the dentin shades (B2 & B1) with translucent shade. Thickness of this translucent layer increased

       from the middle third to the incisal. I also tried to use more translucent shade in proximal areas.



       13
DENT 430, eportfolio Assignemt #4, DBV prep/resto, J. Ghahremani

Each layer of basic shades (B1, B2 & B3) was thinned toward the incisal to be covered by the next

layer. In this way, different layers blend with each other much better.




2. Has surface texture:
Tooth and material consideration:

Surface texture is another esthetic element that should be reproduced in the restoration. It causes

reflection of the light and induces natural appearance. Pattern and extension of the surface texture

is dictated by adjacent natural teeth.



                                   Light reflection due to surface texture




How to do that:
Diamond finishing burs are very useful to achieve this purpose. To make the vertical mesial and

distal depressions, I used the larger tapered diamond polishing burs because thinner burs tend to




14
DENT 430, eportfolio Assignemt #4, DBV prep/resto, J. Ghahremani

create dents and grooves in the surface instead of shallow depressions. I tried to reproduce the

texture of the adjacent tooth on the restoration.

3. Line angles in the correct position:
Tooth and material Consideration:

     Proper positioning of the line angles is very important in the perception of the tooth width

     (Roberson, Heymann, & Swift 2006). Depending on the purpose of the restoration (reproducing

     the existing dimensions, decreasing or increasing them), position of the line angles will be

     determined. If the line angles are too close together, the restored tooth will appear narrower

     and if they are far apart, it will appear wider.




                                 Correct position of the line angles




How to do that:
I tried to duplicate the size and position of the line angles of the adjacent tooth by measuring their

width, their distance from each other and from proximal surfaces by a probe.

15
DENT 430, eportfolio Assignemt #4, DBV prep/resto, J. Ghahremani

4. Correct incisal length:

Tooth and material Consideration:
The length of the incisal edge is dictated by esthetic and functional requirements. To provide a

pleasing appearance, incisal length of the restored tooth should be in harmony with adjacent teeth

and surrounding tissues. To achieve a proper occlusion, especially in lateral and protrusive

excursions, and avoiding hyper-occlusion, the incisal edge should be placed in its correct position

(Okeson, J.P, 2008).




                         Incisal edges of the central incisors are at the same height




How to do that:

In this case, the incisal length of the tooth should be the same as the adjacent central incisor. By

looking at the tooth in different angles and especially from the front and using the adjacent central

incisor as a reference, it is not difficult to achieve the proper length.



16
DENT 430, eportfolio Assignemt #4, DBV prep/resto, J. Ghahremani

5. Smooth contact:

Tooth and material Consideration:

Proximal contact and contour of the restoration should be in such a way that provides periodontal

health, tooth arch integrity and esthetic. Any proximal over hang, ragged or open contact and tight

or wide gingival embrasure should be avoided.




                                     Proper proximal contours & contacts




How to do that:

Most of the contouring should be done before curing the composite by proper using of gold

composite instrument (Felt 6 composite PPI). After polymerization for adjusting the final contour,

hand instruments, finishing strips and finishing burs are effective.




17
DENT 430, eportfolio Assignemt #4, DBV prep/resto, J. Ghahremani




6. No gingival trauma:

Tooth and material consideration:

Preserving the health of surrounding tissues during preparation or restoration is crucial (Newman,

M.G, Takei, H.H 2006). Gingival trauma can induce bleeding that will jeopardize the bonding

process between the restoration and tooth structures. Moreover, gingival trauma may result in

gingival recession and exposure of the margin or discoloration of the composite, which are all

esthetically unpleasant.

How to do that:

By careful attention to the gingival tissue during all stages of treatment from isolation (not using

212 retainer) to preparation (avoiding touching the gingival tissue with the bur) to restoration (not

using wedge) to finishing and polishing (avoiding gingival trauma by finishing burs or strips and

hand instruments).

7. Proper contour (gingival/incisal and mesial/distal):

Tooth and material consideration:

To recreate natural dental anatomy in the restoration, considering facial contour from gingival to

incisal and from mesial to distal is very important. Besides esthetic, proper facial contouring is

important for gingival health and patient’s comfort. From gingival to incisal, there are three

different planes start from emergence profile at gingival and end at incisal edge with gentle curve.

From mesial to distal there are five planes, one in mid-facial two at line angles and two at proximal

(Ash, M., Nelson, S., 2002).

18
DENT 430, eportfolio Assignemt #4, DBV prep/resto, J. Ghahremani




                                                       3
                                     2                                  4

                             1                                              5




                                             Mesial/Distal contour




                                         1




                                 2




                                 3



                                             Incisal/Gingival contour




How to do that:

Visualization of the tooth in different angles is a great help and guide to follow the profile of

adjacent tooth. Be careful not to create distinct and sharp planes instead of blended and gentle

curves.

19
DENT 430, eportfolio Assignemt #4, DBV prep/resto, J. Ghahremani




1. Where did I have the most problems? What did I do to solve these problems?

Using different colors of composite to produce a natural appearance and choosing which color is

suitable for each part was confusing at first. By working with different shades and translucencies

and trying them on unprepared tooth, I learned how to use them and to avoid “over-

characterization”.


2. How will this help you in defining yourself as a dentist?

After doing posterior composite and learning how to use an esthetic material, applying the same

concept in more esthetic zone of the mouth was challenging. I learned that knowing the anatomy,

texture, color and contour of a tooth before doing any esthetic treatment is a crucial prerequisite

that a dentist should learn.




20
   DENT 430, eportfolio Assignemt #4, DBV prep/resto, J. Ghahremani


                                              References:

1. Ash, M., Nelson, S. (2002) Wheeler's Dental Anatomy, Physiology and Occlusion. Saunders Pub Co

2. Ferrari M, Patroni S, Balleri P (1992). Measurement of enamel thickness in relation to reduction for

   etched laminate veneers. Int J Periodont Rest Dent 23:407-413.


3. Goldstien , R.E.(1998): Esthetic in dentistry. Vol 1. B.C. Decker INC


4. Grippo , J.O., Simring, M., Schreiner, S.(2004) Attrition, abrasion, corrosion and abfraction revisited

   A new perspective on tooth surface lesions. J Am Dent Assoc, Vol 135, No 8, 1109-1118

5. Newman, M.G, Takei, H.H (2006): Carranza’s Clinical Periodontology. Saunders Pub Co

6. Okeson, J.P (2008): Management of temporomandibular disorders and occlusion, St. Louis: Mosby.

7. Roberson, T. M., Heymann, H. O., & Swift, E. J. (Ed). (2006). Sturdevant’s Art and Science of

   Operative Dentistry. St. Louis: Mosby.

8. Summitt, J. B., Robbins, J. W., Hilton, T. J., Schwarz, R. S. (2006). Fundamentals of Operative

   Dentistry: A contemporary approach. Chicago: Quintessence Publishing Co, Inc




   21

				
DOCUMENT INFO