The Effect of Computer Guided Occlusal Adjustment on Radiographic Outcome and Masticatory Efficiency of Implant-Supported Overdentures

Objective: The objective of this study was to evaluate the effect of digital occlusal adjustment on the radiographic outcome and masticatory efficiency of mandibular implant-supported overdentures. Material and Methods: Fourteen edentulous male patients were selected for this study. Four implants were inserted at the interforaminal area for all patients as guided by preoperative cone beam computed tomography (CBCT). After three months of ossteointegraton period, all patients were recalled for denture construction and loading the implants with ball & socket attachments. Patients were divided into two groups: Group I received their dentures after occlusal adjustment by selective grinding method using articulating paper only, while group II received their dentures after an additional step of occlusal adjustment using the T-scan III before articulating paper. Patients were recalled for follow up at 1 week, 6 months and 12 months to evaluate bone loss, bone density differences and the masticatory efficiency using ViewGum® software. Two Trident® chewing gums of different colors were asked to be chewed by the patients for 5, 10, 20, 30 and 50 cycles. The specimens were flattened, scanned and uploaded to the View Gum software for analysis. The data of this study were collected, tabulated and statistically analysed by V.22-SPSS statistics software. Results: There were significant differences in bone loss around the implants during the follow up period which was less with dentures underwent occlusal digital adjustment than using articulating paper only. The bone density from the 1 week baseline showed to be increasing in the T-scan III group (Group II) but insignificantly except at the distal and mesial surfaces of both implants at the premolar area compared to their counterpart in the other group. Regarding the ViewGum analyses, 20 chewing cycles showed to be the most reliable cycles test as it was the only test producing realistic results. Accordingly, T-scan III group (Group II) showed less variation of hue value which indicates higher degree of homogeneity of both gums colour and better of mixing ability. Conclusion: T-scan III aided significantly in the process of occlusal load distribution which resulted in less marginal bone loss, more bone density gaining around the implants and better mixing ability of the food intake which enhance the masticatory efficiency.