PERIOTEST METHOD - IMPLANT-SUPPORTED FRAMEWORK FIT EVALUATION IN-VIVO

Statement of problem. In implant prosthodontics an accurate fit of the framework to the supporting implants is paramount. However, microgaps occur, unknown to the clinician until complications arise that implic ate errors in fit. Therefore prosthodontics would welcome a tool or in strument that provides an objective evaluation of the fit at the impla nt prosthodontic interface. Purpose. This clinical investigation deter mined whether a correlation existed between the laboratory laser measu rement of the abutment analog-framework fit and the intraoral abutment -framework fit as measured by the Periotest method. Material and metho ds. Fifteen subjects received implant-supported remote fixed partial d enture supported by five (11 subjects) or six (4 subjects) implants in the mandibular jaw opposed by a complete maxillary denture. Laser vid eography was used to quantify the fit of the framework to its respecti ve master cast with six measurements, while the fit of the framework i n the mouth was quantified with the: Periotest method. Data were stati stically analyzed with correlation analyses and multiple regression. R esults. The overall correlation coefficient between the two methods wa s r = 0.51. Regression analysis of variance revealed that the intercep t of the laser videography measurement was significant (P less than or equal to 0.05). The mean Periotest values and standard deviation for the abutment-framework interface were negative (-7.3 +/- 1.2). The var iance in part for the Periotest values was explained by the misfits in the vertical axis (Delta Z, + 0.471) and in the misfit direction of t he centroids in the x-y plane (X-YVD, -0.244). Conclusion. There was n o single variable among the six measurement variables that strongly co rrelated with the Periotest method in the identification of misfit at the bearing surface as indicated by the Periotest value measurements. The misfit laser variables that were weakly correlated to the Periotes t values should be observable clinically with greater scrutiny.