Piezoelectric surgery in implantology

Int J Periodontics Restorative Dent. 2000 Aug;20(4):358-65.

Piezoelectric surgery in implantology: a case report--a new piezoelectric ridge expansion technique.
Vercellotti T

The purpose of this preliminary article is to present a new surgical technique that, thanks to the use of modulated-frequency piezoelectric energy scalpels, permits the expansion of the ridge and the placement of implants in single-stage surgery in positions that were not previously possible with any other method. The technique involves the separation of the vestibular osseous flap from the palatal flap and the immediate positioning of the implant between the 2 cortical walls. The case report illustrates the ridge expansion and positioning of implants step by step in bone of quality 1 to 2 with only 2 to 3 mm of thickness that is maintained for its entire height. To obtain rapid healing, the expansion space that was created for the positioning of the implant was filled, following the concepts of tissue engineering, with bioactive glass synthetic bone graft material as an osteoconductive factor and autogenous platelet-rich plasma as an osteoinductive factor. The site was covered with a platelet-rich plasma membrane. A careful evaluation of the site when reopened after 3 months revealed that the ridge was mineralized and stabilized at a thickness of 5 mm and the implants were osseointegrated.

Strains Recorded in a Combined Tooth-Implant Restoration: An In Vivo Study

Implant Dentistry. 14(1):58-62, March 2005.
Ormianer, Zeev DMD *; Brosh, Tamar PhD +; Laufer, Ben-Zion DMD *; Shifman, Arie DMD +

Abstract: Implant-supported fixed prosthesis is a treatment option to restore missing teeth. Occasionally, it is necessary to connect teeth and implants as abutments for these restorations. Whether such restorations can be recommended is a matter of debate. This in vivo study measured strains involved in connecting implants to a natural tooth and compared rigid and nonrigid tooth/implant connections. A patient was treated with mandibular unilateral fixed prosthesis supported by two implants and one proximal tooth. Strain gauges were cemented to the experimental framework restoration. Recordings were obtained from the restorations while the patient bit on a wooden stick on the day of placement and after 2 weeks in function, using both rigid and nonrigid attach-ment connections. A significant differ-ence was found in horizontal deformation of the tooth/crown between day 1 and 2 weeks later. Vertical deformations were smaller than horizontal ones. After applying biting forces, horizontal and vertical deformations were maintained. Strain recorded in a clinical setting revealed mostly horizontal strains generated in a combined tooth/implant device. These strains were maintained after a 2-week recording. Within the limitation of this study, combined tooth/implant restorations could be a potential complication and could cause an intrusion of a natural abutment regardless of the type of connection (rigid or nonrigid).

Effects of splinted prosthesis supported a wide implant or two implants: a three-dimensional finite element analysis.

Clin Oral Implants Res. 2005 Aug;16(4):466-72
Huang HL, Huang JS, Ko CC, Hsu JT, Chang CH, Chen MY.

Institute of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan.

OBJECTIVES: Three-dimensional finite element (FE) models of splinted prosthetic crowns were studied and stress analyses were evaluated with different types of implant support, including standard, wide or two implant(s) for partial, posterior edentulous restorations. MATERIAL AND METHODS: The FE models were constructed based on a cadaver mandible containing the 2nd premolar and the 1st molar. The crowns of these two teeth were modeled as connected and disconnected to mimic the splinted and non-splinted designs, respectively. One standard implant was placed at the premolar region, while three types of implant support, one at a time (the standard implant, wide implant and two implants), were used to support the molar crown. A 100 N oblique load was applied to the buccal cusp on each crown. The FE simulation was validated experimentally via strain gauge measurement.
RESULTS: The experimental data were well correlated with the FE predictions (r(2)=0.97). When compared with the standard implant used in the molar area, the wide implant and two implants reduced the peak stress in crestal bone by 29-37% for both splinted and non-splinted cases. Inserting the standard implant into both the premolar and molar area, the bone stresses were identical for splinted and non-splinted designs. However, splinting the adjacent crowns has shown to decrease the bone stresses at the premolar region by 25%, while the wide implant or two implants were placed at the molar region.
CONCLUSION: The biomechanical advantages of using the wide implant or two implants are almost identical. The benefit of load sharing by the splinted crowns is notable only when the implants on the premolar and molar regions have different supporting ability.

Multidisciplinary Treatment Approach for Enhancement of Implant Esthetics.

Implant Dentistry. 14(1):21-29, March 2005.
Wang, Hom-Lay DDS, MSD *; Shotwell, Jeffrey L. DDS, MS +; Itose, Tatsumasa DDS ++; Neiva, Rodrigo F. DDS, MS [S]

A "team approach" that includes different specialties from the initial stages of implant treatment is important to achieve predictable and esthetically pleasing outcomes in compromised dental replacement cases. This report describes a severely compromised case that was properly managed by the combined efforts of a team of specialists. Briefly, prior to tooth extraction, orthodontic forced eruption was applied to coronally displace the attachment apparatus (i.e., hard and soft tissues). Then, atraumatic tooth extraction together with immediate implant placement was performed. The "sandwich bone augmentation" technique was used to augment the deficient buccal alveolar ridge. A second stage surgery was performed 6 months after healing, revealing 100% of bone fill/augmentation. This technique allowed fabrication of a final restoration that respected the proportions of the natural dentition in a case that would otherwise result in a poor esthetic outcome.