An evaluation of angles between the alveolar crest bone and the implant effect on the implant crestal area induced stresses using a finite element method / 대한치과보철학회지

STATEMENT OF PROBLEM: Main consideration was given to the stresses at the site of implant entry into the cortical bone at the alveolar crest. As a suspectible factor affecting the occurrence of stress concentrations, the contact angle between the implant and the alveolar crest bone was addressed. PURPOSE: The purpose of this study is to evaluate angles between the alveolar crest bone and the implant effect on the implant crestal area induced stresses using a finite element method. MATERIAL AND METHODS: Cylindrically shaped, standard size ITI implants entering into alveolar crest with four different contact angles of 0, 15, 30, and 45 deg. with the long axis of the implant were axisymmetrically modelled. Alterations of stresses around the implants were computed and compared at the cervical cortical bone. RESULTS AND CONCLUSION: The results demonstrated that regardless of the difference of the implant/alveolar crest bone contact angles, stress concentration occurred at the cervical bone and the angle differences led to insignificant variations in stress level.

Radiographic evaluation of the proximal bone level between two implants: A 3-year comparative study between Branemark and ITI implants in the mandibular posterior region / 대한치과보철학회지

STATEMENT OF PROBLEM: Branemark or ITI are two currently most widely used implant systems but with contrasting design, surgical and restoration methods. PURPOSE: The purpose of this study was to compare changes and its statistical significance in bone height and shape which may rise due to the differences between two implant systems. Also to analyse the effect of inter-implant distance on annual bone height changes. MATERIAL & METHOD: Those patients who were treated with two or more of either Branemark or ITI implants at posterior mandibular area at Yonsei University Dental Hospital, Implant Clinic were selected. At annual examination appointments, standardised radiographs using parallel technique were taken. Marginal bone and inter-implant crestal bone changes were measured and following results were obtained. RESULTS: 1) When ITI and Branemark system were compared, both annual marginal and inter-implant crestal bone height changes in ITI system in the first two years were smaller than Branemark and they were statistically significant. On the third year, however, there was no statistical difference between two implant systems on their annual bone level changes (p>0.05). 2) The Marginal and inter-implant crestal bone changes were compared when inter-implant distance was less than 4mm. Statistically significant bone level changes were noted on the first year only for ITI implants but in the first and second year for Branemark implants (p>0.05). 3) When comparing angulation changes between marginal bone and implant fixture, ITI system had smaller angulation changes but the annual changes were not statistically significant (p>0.05). CONCLUSION: Within the limitation of this study, it could be concluded that Branemark implant systems had more changes in marginal and inter-implant crestal bone level in the first and second year after loading with statistical significance. Further studies are recommended to see the effects of these bone loss during the first and second year after loading on the long term prognosis of Branemark Implants.

Comparative Study About Jaw Biocompatibility Of National Avana And International Iti Implant