<p>Objectives: Temperature changes along an implant body have not been widely studied. The objectives of this in vitro study were (i) to establish if the temperature of the abutment influences the temperature of the implant surface, (ii) to establish the temperature transmission from abutment to implant body, and (iii) to establish for what abutment temperature the critical time/temperature threshold of 47oC for 1 minute at implant level is reached.</p>

Diss. (sammanfattning) Göteborg : Göteborgs universitet, 2008.

Diss. (sammanfattning) Göteborg : Göteborgs universitet, 2008. / Härtill 4 uppsatser.

<p>Objectives: Temperature changes along an implant body have not been widely studied. The objectives of this in vitro study were (i) to establish if the temperature of the abutment influences the temperature of the implant surface, (ii) to establish the temperature transmission from abutment to implant body, and (iii) to establish for what abutment temperature the critical time/temperature threshold of 47oC for 1 minute at implant level is reached.</p>

Rehabilitation of edentulous patients with Implant-supported Complete Fixed Dental Prosthesis (ICFDP) is a well-documented treatment option. This dissertation assessed the relation between the rate of biological/mechanical complications and the type of metal framework alloy, length of cantilever extension. The results showed that long-term clinical outcomes of ICFDP were favorable. While 30% of patients experienced biological complications, 66.6% of the prostheses needed to be repaired during follow-up period. The risk of prosthesis failure and mechanical complications was significantly higher in silver-palladium frameworks as compared with palladium-silver or type IV gold alloys. The length of cantilever was not correlated with the amount of marginal bone loss. The rate of marginal bone loss around anterior implants was higher than that of posterior implants associated with cantilever segments. The treatment improved the patients’ quality of life and 96% of patients would undergo the same treatment again if required.

Rehabilitation of edentulous patients with Implant-supported Complete Fixed Dental Prosthesis (ICFDP) is a well-documented treatment option. This dissertation assessed the relation between the rate of biological/mechanical complications and the type of metal framework alloy, length of cantilever extension. The results showed that long-term clinical outcomes of ICFDP were favorable. While 30% of patients experienced biological complications, 66.6% of the prostheses needed to be repaired during follow-up period. The risk of prosthesis failure and mechanical complications was significantly higher in silver-palladium frameworks as compared with palladium-silver or type IV gold alloys. The length of cantilever was not correlated with the amount of marginal bone loss. The rate of marginal bone loss around anterior implants was higher than that of posterior implants associated with cantilever segments. The treatment improved the patients’ quality of life and 96% of patients would undergo the same treatment again if required.

Objectives: To compare the osseointegration of conventionally and immediately restored tapered implants in a split-mouth animal model, and to compare different methods of analysis for measuring osseointegration. Materials & Methods: Twenty tapered implants were placed in the posterior mandibles of ten sheep, three months after premolar extractions. Ten control implants were placed and were restored after three months submerged healing. Ten test implants were placed on the contralateral side at this time and immediately restored. Animals were sacrificed after a further three months healing. Resonance frequency analysis (Implant Stability Quotient, ISQ), and standardized radiographs were taken at all stages. Alveolar bone height relative to the implant shoulder was measured on digitized radiographs. Histomorphometric and micro-Computed Tomograph ([mu]CT) morphometric analysis for Bone-to-Implant Contact (BIC) and Bone Density (BD) were performed. Radiographic, stability and morphometric measurements were compared statistically. Results: Only three (30%) of conventionally restored and two (20%) immediately restored implants survived (p = 0.74). Mean crestal bone level after three months loading differed significantly (control 5.3 � 0.9 mm versus test 0.9 � 1.3 mm; p = 0.02). Control implants lost more crestal bone over three months than test implants but this was not statistically significant (3.5 � 1.0 mm versus 0.7 � 1.0 mm; p = 0.06). The test group showed a higher mean ISQ value (85.4 � 6.9) compared to the control group (72 � 14.4; p = 0.349). Both groups showed a slightly reduced stability during the loaded period. This was more marked for the test group but not statistically significant (-0.5 � 3.8 ISQ versus -4.35 � 6.6 ISQ; p = 0.8). A statistically significant negative correlation was found between the loss of crestal bone and ISQ with loading (Pearson�s coefficient of correlation r = -0.473 p = 0.026). Both groups showed a statistically significant difference in BIC for both histomorphometric analaysis (HMA); p = 0.039 and [mu]CT morphometric analysis; p = 0.013. When the two forms of morphometric analysis were compared, HMA and [mu]CT morphometric analysis differed significantly for both BIC (p = 0.05) and BD (p = 0.048). However, a statistically significant correlation was found between the two measuring techniques, for both BIC (r = 0.335 p = 0.013) and BD (r = 0.439 p = 0.01). Conclusions: The placement of wide-bodied 3i Osseotite NT[TM] tapered implants into sheep mandible resulted in high failure rate regardless of the loading protocol. The sheep mandibular model may be inappropriate as a model for evaluation of immediate loading, and to test implants which are designed for soft bone. Further investigations are needed to look into the variations in bone microstructure along with their impact on the mechanics of implant-bone union. Although a statistically significant difference was found between the two measurement techniques, a positive correlation was found between HMA and [mu]CT morphometric analysis suggesting non-invasive methods may have a potential in assessing osseointegration. Further research is required to optimize the variables in [mu]CT analysis, such as, voltage, filters, and thresholding to minimize artifacts and to maximize bone contrast when titanium implants are present.

Objective: The aim of the study was to evaluate the clinical outcomes of oral implant treatment provided at the School of Dentistry, University of Otago from 1989 to 2005. Methods: Oral implant patients (n=320) with 586 implants were identified and invited to attend for a clinical examination. Implant demographics of all the patients were extracted from the files. Implant demographics of the examined and unexamined patients were compared to assess if the examined patients were representative of the total group. One hundred and three patients with 214 implants agreed to attend for an examination. In the clinical examination full mouth plaque scores, probing depths, bleeding on probing and suppuration were measured. In addition, around implants recession and width of keratinized gingiva were also recorded. For the radiographic examination, baseline radiographs and radiographs taken at the time of examination were digitized and compared to measure the amount of bone lost or gained around implants using NIH Image J software. Results: There were equal numbers of males and females with a mean age of 46.3 � 15 years at the time of implant placement. The smoking history at the time of examination was recorded, 56% of the patients were non-smokers, 37% former smokers, and 7% were current smokers. More than half of the implants (56%) were placed in the anterior region. Based on the type of implant system, 79% were Branemark implants, 10% Straumann, 6% Southern implants and 4% were unknown. Most of the patients (64%) had implant-supported crowns, 19% had fixed denture prostheses, and 17% had implant-supported overdentures. The overall implant survival rate was 97.7% with five implants lost (2.3%) and 8 implants treated for peri-implantitis (3.8%). The mean PD around implants was 2.3mm (SD 0.6mm), mean recession was 0.5mm (SD 0.8mm) and mean attachment level of 2.8mm (SD 0.9mm). Probing depths [greater than or equal to] 4mm with BOP were recorded around implants in 8.9% of patients. The mean full mouth plaque score was 30% while mean plaque score around implants was 15.9%. The average bone loss around implants was 0.3mm (SD 0.8). Maximum bone loss observed was 2.9 mm. Conclusion: The prevalence of peri-implant inflammation and implant survival rates in this group of patients appeared comparable to that reported in the literature. The prevalence of peri-implant lesions was low in the group of patients examined.

Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 5 uppsatser.

Thesis (M.S.)--University of Michigan, 1988.