Redesigning Macrostructure of Dental Implant for Better Initial

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					                                                                                                           6/22/2011

Redesigning Macrostructure of Dental Implant for
Better Initial Stability & Reduction of Tissue Recession
Introduction

B    ecause of the improvement of dental implant surgical protocol, restorative dentist can restore dental implant
     immediately with high patient’s satisfaction initially. However, subsequent tissue recession 1 can result in
loss of supporting tissue 2, loss of osseousintegration, loss of aesthetics and total failure of treatment. One new
double-margin implant design was introduced in 2008. Not only the newly introduced dental implant can be used
in almost all clinical situations, its asymmetric thread design which allows minimum preparation of implant site
can enhance high levels of initial stability even in area of soft bone and fresh socket, making it a good implant
choice for immediate extraction, immediate implant placement, immediate impression and immediate load cases.
Further, the implant has the feature of double-margin design with anodization 3 3 (yellow and magenta) collar,
approximately 1.2mm in vertical height, designed to improve aesthetics in case of implant exposure or subsequent
tissue recession. The anodized collar of dental implant can provide much smoother surface than machined titanium
surface, rough titanium surface and microthreaded surface in the coronal portion of other dental implants. The
anodized collar which can provide a mirror-like smooth surface can also reduce dental plaque deposition to
prevent subsequent tissue recession 4. The double-margin design also allows restorative dentist to relocate margin
in case of implant exposure or subsequent tissue recession. Three clinical cases were presented to illustrate the
clinical application.

Redesigned dental implant system
The dental implant system which consists of dental implant, fixture mount abutment and
abutment screw [Fig.1] is specifically designed for the purpose of immediate implant
placement and immediate impression taking. The new design employs several modern
concepts not only to establish high insertion torque and enhance the primary stability but also
to provide multiple applications of an implant fixture mount.

Platform Switching Design
The dental implant has a platform switching design [Fig.1] can reduce stress to crestal bone
6
  . Platform switching design also can minimize the loss of crestal bone height.
                                                                                                               Fig. 1
The IDI implant is designed to be placed at bone level. The coronal portion
of the implant has a platform switching design, which is intended to
maximize the alveolar bone around the collar of the implant and provide
soft-tissue support 7-9.

Double-Margin Design with Anodization III Collar
The implant has the feature of double-margin design [Fig. 2] with
anodization 3 3 (yellow and magenta) collar, approximately 1.2mm in
vertical height, designed to improve aesthetics in case of implant exposure
or subsequent tissue recession. The anodized collar [Fig. 3] of the dental
implant can provide much smoother surface than machined titanium
surface, rough titanium surface and microthreaded surface in the coronal
portion of other dental implants. The anodized collar which can provide
a mirror-like smooth surface can also reduce dental plaque deposition so
as to prevent subsequent tissue recession 3, 4. This double-margin design
also allows restorative dentist to change margin location in case of implant
                                                                                                  Fig. 2
                                                                                                                        1
                            Redesigning Macrostructure of Dental Implant for Better Initial Stability & Reduction of Tissue Recession


exposure or subsequent tissue recession. Most of the rough surfaces cannot be avoided 4.

Thread Design
     i. Micro Thread
The microthread design [Fig 3] which is located            1.2mm Color         Apically relocated
                                                                              microthreads to avoid    Asymmetrical sharp
1.3mm apical to platform can counteract                   Anodization III
                                                                                tissue recession       and deep threads to
                                                       mirror-like surface to                         enhance initial stability
marginal bone resorption in accordance with minimize inflammation
Wolff’s law 10 and increase the resistance to and tissue recession
shear forces significantly and to optimize
implant stability in suboptimal clinical
conditions 11. It is worth to mention that the Fig. 3
relocated micro thread of IDI implant, not like
other companies’ product, such as, Astra Tech® Micro Thread implants, which can result in significant bone
destruction while unintentional perforation of two-stage implants thread exposure 2.
     ii. Body Thread Design
The body thread [Fig 2] of IDI dental implant                                                                         Fig. 4

is a deeper, single thread design (Triple thread
design can increase micro-motion.) 12, 13.
Further, the new design of thread (asymmetric
thread design) is focusing on increasing apical
face angle/ decreasing coronal face angle
[Fig. 4] and narrowing implant apex to reduce
resistance of dental implant insertion coupled
with underpreparing implant site which can
maximize bone preservation. This design
allows for gradual expansion of the bone as
the implant advances, which is similar to the
utilization of osteotome 14, 15 to achieve high insertion torque (90Ncm) and increase initial stability. It is appropriate
for immediate dental implant placement and immediate loading with appropriate occlusal loading even under the
circumstances of compromised quality of alveolar bone.

Sinolift Feature
A sinolift feature [Fig 2] which forms a concaved/threaded cavity with different variations is located at apical
end. This design is to be functional as osteotome which can simultaneously lift maxillary sinus and condense the
bone 15-17.

The implant design allows for preparing a narrower-than-typical initial implant osteotomy and placing the implant
in a method similar to turning a “corkscrew.” This allows for gradual expansion of the maxillary alveolar bone
and cortical bone of sinus floor as the implant advances, similarly to the use of an osteotome 5 to lift sinus floor
in a much smoother manner to avoid possible complication of rupturing Schneiderian membrane, which allows
dentist to place dental implant and perform sinus elevation simultaneously in a compromised implant site with a
much better result 17.

Highly Compatible SBM Surface Treatment
The surface of the Dental Implants has a highly biocompatible roughness [Fig. 5] that proved to be excellent
for osseointegration 18,19. The implants are blasted with a resorbable SBM from apex to implant body and then
removing all residues from the blasting material 20. However, the 1.2mm neck collar area [Fig. 3] remains anodized
smooth surface 3.                                                                                                                       2
                         Redesigning Macrostructure of Dental Implant for Better Initial Stability & Reduction of Tissue Recession


Case Presentations
Case 1
A male patient, age 61, was admitted with a horizontal tooth crack
with tooth # 26 (Photos 1 and 2). Clinical findings revealed lack
of ferrule at tooth #26 with poor prognosis. After consultation
and treatment option given, patient elected to have #26 to be
extracted and one implant was immediately placed at # 26
position (3.5x13.5mm IDI Dental Implant). A newly designed
torque wrench was utilized for final torque of dental implant.
The measurement of final torque was 80Ncm. Immediately
after implant placement, final impressions were taken using the
fixture mount abutment and ball impression screw as impression
copings (Photos 3 and 4) was placed . Provisional abutment was
placed. A single screw-retained restoration for #26 (Photo 5 and
6) was delivered on the same day in 6 hours after tooth extraction
and dental implant placement. 18-month post delivery check
revealed good stability of the dental implant and restoration
(Photo 7). Soft tissue and osseous tissue recession was very
                                                                                                                        Fig. 5
minimum.

The 18-month follow-up radiograph (Photo 8) also reveals less
alveolar bone loss of IDI dental implant at tooth # 26 position comparing to tooth #
27 position replaced by Nobel Biocare® 4.3mm x 13.5mm dental implant. The bone
level of Nobel Replace® dental implant resorbed to first thread after 3-year follow-
up. The bone level of IDI dental implant placed on tooth # 26 maintained bone level
near platform level after 18-month follow-up.
                                                                                  Photo 1
Case 2
A 63-year old male patient presented with
edentulous maxillary and mandibular arches
(Photo. 9) with moderate to severe bone loss.
After clinical evaluation, we have determined                                                                          Photo 2
to restore edentulous maxilla and mandible with
dental implant supported fixed restorations. The
result alveolar bone would be restored by pink
                                                                           Photo 3
ceramic. A flapless operation was performed.
Sixteen dental implants were placed on maxillary
and mandibular arches. The final torques for all
implants were approximately between 50NCm
and 85Ncm. After abutment screws were removed,
ball screws were utilized to secure the fixture
mount abutments. Both maxillary and mandibular
final impressions were made immediately after
implant placements with polyvinylsiloxane. Facebow and CR record were made
immediately after impressions. Full contour waxup (Photo 10) for both arches was                                       Photo 4
also made. A definitive restoration (Photo 11) was delivered about 4 weeks later. The
post delivery revealed good stability and good aesthetic result. Patient was pleased with the outcome.
                                                                                                                                     3
Redesigning Macrostructure of Dental Implant for Better Initial Stability & Reduction of Tissue Recession




                                                                                             Photo 7
                                             Photo 6
  Photo 5




                                                                                             Photo 9



                                           Photo 8




                                                                                             Photo 11




                                            Photo 10


                                                                                             Photo 12

                                                                                                            4
                         Redesigning Macrostructure of Dental Implant for Better Initial Stability & Reduction of Tissue Recession

Case 3
A 59-year old female patient presented with severe resorbed edentulous maxilla (Photo. 12). She had used complete
denture for 25 years. After she was examined, we had determined that the anterior resorbed maxillary ridge did
not have enough alveolar bone to house dental implants. A flapless operation was performed. Nine dental implants
(Photo 13) were placed in both maxillary posterior area. Actually, two of dental implants were placed at tuberosity
area of both sides of maxilla.
Six-month healing period was provided for osseous integration. All dental implants were integrated.
Polyvinylsiloxane were utilized for final impression. Facebow and CR record were made simultaneously. A solid
cast was made.(Photo 14) Full contour waxup was carefully made (Photo 15)subsequently. Vertical dimension

                              Photo 13




                                                                                                                       Photo 15

                              Photo 14                                                                                 Photo 16




                                                                                                                      Photo 17
was increased 1mm at second molar area to reduce the
effect of class III malocclusion due to the resorbed
anterior maxillary area. As a result, we could restore
the resorbed maxilla with an implant supported
fixed complete restoration (Fig. 16 & 17) rather than
overdenture. A good aesthetic result was achieved.
Patient was very pleased with the outcome.

Conclusion
The IDI dental implant was designed to improve initial stability in compromised bone that makes it a proper
implant choice for different clinical applications. The anodized collar design allows for improving aesthetics while
implant exposure. Sinolift® feature was designed to be used as osteotome simultaneously lifting the maxillary
sinus and condensing the bone. A threaded internal tunnel in the apical portion provides antilock effect.

Couple with the new designed fixture mount/impression coping/temporary abutment, the clinician can take an
immediate final impression right after implant placement. A cast can then be immediately poured for wax up and
a screw-retained/cement retained provisional prosthesis is fabricated and early loading can be made in hours.


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                        Redesigning Macrostructure of Dental Implant for Better Initial Stability & Reduction of Tissue Recession


References

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