ABSTRACT
OBJECTIVE: Marginal bone loss (MBL), a prognostic parameter for implant success, is associated with implant- and patient-related variables. The purpose of this study was to analyze the effects of the crown-to-implant ratio and independent factors of implant diameter, implant length, implant type, location, and platform switching on distal and mesial MBLs at the 6-, 12-, 24-, and 36-month recall sessions of single crown implant-supported restorations. METHOD AND MATERIALS: Radiographic and clinical data of patients treated with single crown implants were collected. MBL was measured at the baseline and recall sessions on panoramic radiographs. The crown-to-implant ratio was calculated by dividing the length of the crown by that of the dental implant. RESULTS: The crown-to-implant ratio had a moderately positive correlation with distal MBL at the 6-month recall session (P < .05, r = 0.469) and a weakly positive correlation at the 12- (P < .05, r = 0.220), 24- (P < .05, r = 0.214), and 36- (P < .05, r = 0.250) month recall sessions. Distal and mesial MBL did not significantly differ among the four implant types at any recall session (P > .05). The crown-to-implant ratio had no significant correlation with mesial MBL at the 12-, 24-, or 36-month recall session (P > .05), and a moderately positive correlation at the 6-month recall session (P < .001, r = 0.434). CONCLUSIONS: MBL was similar among different implant types in the short and medium terms. There was a positive correlation between distal MBL and the crown-to-implant ratio.
Subject(s)
Alveolar Bone Loss , Dental Implants , Crowns , Dental Prosthesis Design , Dental Prosthesis, Implant-Supported , Follow-Up Studies , Humans , Retrospective StudiesABSTRACT
PURPOSE: Erbium, chromium: yttrium, scandium, gallium, garnet (ErCr:Ysgg) lasers have been frequently used in oral surgical procedures and are almost seen as alternatives to diode lasers. The aim of this comparative study was to analyze in an animal model the thermal elevation induced by ErCr:Ysgg and diode lasers in soft tissue and bone. MATERIALS AND METHODS: Thirty freshly dissected sheep mandibles containing bone and soft tissue were divided into 120 equal parts. Gallium-aluminum-arsenide (Ga-Al-As) diode laser (λ=940 nm) with 1, 2 and 5 W output powers and ErCr:Ysgg laser (λ=2780 nm) with 2.75, 4.5 and 6 W output powers were used on soft and bone tissues separately for 3 seconds with point application. Mean temperature values before and after application of the lasers were compared in soft tissue and bone. RESULTS: The minimum mean temperature value was observed with 2.75 W ErCr:Ysgg laser while irradiation with 5 W diode laser created the maximum values (p<0.05). CONCLUSION: ErCr:Ysgg laser (λ=2780 nm) with 2.75 W power generates low levels of heat compared to diode lasers and may provide safer surgery in soft and bone tissues without destructive effects of temperature increase.
