Objectives: Lasers are often used in clinical dentistry. Reports have shown they are effective for soft tissue management around implants and treatment of periimplantitis. However, few reports have examined the effects of laser-generated heat. This study analyzed potential surface alterations and temperature changes caused by laser use.
Materials and methods: SLA (sandblasted, large grit, acid etched) and raw surface titanium plates were irradiated using CO2 (fiber and multijoint) and diode lasers. The specimens were examined by scanning electron microscopy. The SLA titanium implants were irradiated using fiber CO2 lasers and temperature changes were measured.
Results: After CO2 (multijoint) laser application, SLA surface titanium discs showed melting alterations of the surface, but showed no alterations after application of CO2 (fiber) and diode lasers. The temperature increase was directly related to wattage and exposure time and did not change in excess of 3℃ by fiber CO2 laser application (1-2 W, 5 seconds, SP or RPT mode).
Conclusion: Periimplantitis can be successfully treated by fiber CO2 laser application (2 W, 5 seconds, SP or RPT mode) without damaging the implant surface or osseointegration.
This study was designed to evaluate the initial adherence (during the first hour) of Porphyromonas gingivalis (P.g.) as well as the surface characterization of alumina-coated titanium using a physical vapor deposition technique in order to reduce the adherence of bacteria to titanium implants. The coatings were defect-free films approximately 2 μm thick that were strongly adhered to the titanium substrate and were identified as αalumina. The contact angle to water was 63 degrees (SD: 5 degrees), which was almost equal to that of titanium. The zeta potential at pH 7.0 was 22.4 mV (SD: 3.2 mV), indicating positively charged at around pH 7. The amount of initial adhesion of P.g. was remarkably decreased on alumina-coated surfaces compared to polished titanium. The adherence of P.g. was considered to be related to the surface electrical charge of the materials.These results suggested that a thin alumina coating on titanium is a promising method for reducing the initial adhesion of oral bacteria.
Wireless resonance vibration frequency analysis (RFA) is one of the new methods for measuring implant stability. The implant stability quotient (ISQ) values obtained using Osstell mentor make it possible to evaluate the implant stability non-invasively and objectively. However, few attempts have been made to examine the ISQ values using Osstell mentor and its relation with the implant stability of cortical bone (its thickness, width and density). In this study, we investigated factors affecting the ISQ value obtained by wireless RFA using mandibular cortical bone models of a pig.
After preparing pigʼs mandibular bone having different bone densities by the decalcifying method, pigʼs bone models excluding cavernous bone were made. We installed an implant fixture (Replace Select Tapered) in the pigʼs bone models under various conditions of thickness, width and density and examined the ISQ values by wireless RFA. We also investigated the correlation between ISQ value and length (10 mm, 13 mm and 16 mm) or width (3.5 mm, 4.3 mm and 5.0 mm) of the implant fixture installed in the model.
The results are summarized as follows:
1. ISQ value was significantly lower in the bone models with low density of cortical bone than those with high density.
2. ISQ value was higher in the bone models with high thickness of cortical bone than those with low thickness. However, a significant association was not found.
3. There were no differences between ISQ value and width of cortical bone.
4. There were no differences between ISQ value and length of implant fixture.
5. ISQ value of the fixture with narrow width (3.5 mm) was significantly lower than those with wide width (4.3 mm and 5.0 mm) in the bone model with low density of cortical bone.
These results indicated that ISQ values obtained by wireless RFA were affected by the bone density and thickness of cortical bone. Wireless RFA is a useful method for measuring implant stability.
The objective of this study was to estimate bone induction by a bioabsorbable hydroxyapatite block (functionally graded hydroxyapatite: fg-HAp, 3×3×3 mm)/rhBMP-2 (5 μg) on rat skull periosteum, the absorption of fg-HAp, compared with non-absorbable hydroxyapatite (BONECERAM®). In the fg-HAp/BMP-2, bone formation started in the outer layer of the ceramics at 1 week after implantation and induced bone was found in the middle part at 4 weeks. In both the fg-HAp alone and the fg-HAp/BMP-2 groups, body fluid permeated into the bulk of fg-HAp scaffold and then fg-HAp block was gradually fragmented by autodegradation and bio-absorption. On the other hand, in the non-absorbable HAp/BMP-2, bone was found locally in the surface layer of the HAp at 4 weeks. In the fg-HAp alone and the non-absorbable HAp alone, bone formation never occurred in this model.
Therefore, our fg-HAp is an bio-absorbable ceramic and the fg-HAp/BMP-2 supra-periosteal implant might be a superior bone reservoir system.