MATERIAL AND METHODS: Thirty-four patients (mean age 60.70  ±  8.7 years) received telescopic crown or locator attachments for ISOD and completed OHIP-14 (Malaysian version) and DS questionnaires, at baseline (T0 ) with new conventional complete dentures (CCD) and 3 months (T1 ) and 3 years (T2 ) after ISOD conversion. Mandibular bone volume was calculated from cone beam computed tomography (CBCT) datasets using Mimics software. Mean changes (MC) in OHIP-14 and DS at intervals were analyzed using the Wilcoxon signed-rank test and effect size (ES). The association of bone volume, implant attachment type, and other patient variables with the change in OHIP-14 and DS were determined using multivariate linear regression analysis.

RESULTS: The MC in OHIP-14 and DS scores from T0 to T1 and T2 showed significant improvement with moderate and large ES, respectively. Regression analyses for the change in OHIP-14 score from T0 to T2 showed significant association with implant attachment type (P = 0.043), bone volume (P = 0.004), and baseline OHIP-14 (P = 0.001), while for DS, the association was only significant with baseline DS score (P = 0.001).

METHODS: Root canal was prepared using stainless steel K-files™ and ProTaper™ and subjected to manual and ultrasonic irrigation using 6% NaOCl+2% CHX, 6% NaOCl+2% QAS and saline as control. For confocal-microscopy, Raman spectroscopy and SEM analysis before and after treatment, Enterococcus faecalis cultured for 7 days. Raman spectroscopy analysis was done across cut section of gutta percha/sealer-dentine to detect resin infiltration. Indentation of mechanical properties was evaluated using a Berkovich indenter. The contact angle of irrigants and surface free energy were evaluated. Mineralization nodules were detected through Alazarin red after 14 days.

RESULTS: Control biofilms showed dense green colonies. Majority of E. faecalis bacteria were present in biofilm fluoresced red in NaOCl+2% QAS group. There was reduction of 484cm-1 Raman band and its intensity reached lowest with NaOCl+2% QAS. There was an increase in 1350-1420cm-1 intensity in the NaOCl+2% CHX groups. Gradual decrease in 1639cm-1 and 1609cm-1 Raman signal ratios were seen in the resin-depth region of 17μm>, 14.1μm> and 13.2μm for NaOCl+2% QAS, NaOCl+2% CHX and control groups respectively. All obturated groups showed an intact sealer/dentine interface with a few notable differences. 0.771 and 83.5% creep indentation distance for NaOCl+2% QAS ultrasonic groups were observed. Highest proportion of polar component was significantly found in the NaOCl+2% QAS groups which was significantly higher as compared to other groups. Mineralized nodules were increased in NaOCl+2% QAS.