Pulpal Deterioration Following Restorative Procedures: A Case - Control Study.

Introduction: While restorative procedures aim to preserve tooth structure and function, they may contribute to pulpal deterioration, potentially necessitating endodontic intervention. This matched case-control study examined the time lapse from the most recent definitive (terminal) restoration to the onset of pulpal deterioration.

Methods: A computerized search of dental records (1999-2023) at the University of Toronto identified 1,360 permanent teeth that received terminal restorations followed by endodontic therapy (cases), matched 1:1 with 1,360 teeth that received terminal restorations without subsequent endodontic therapy (controls). Matching criteria included age at the time of restoration, tooth type, and number of prior restorations. Data were analyzed using descriptive statistics, chi-square tests, and multivariable Cox regression.

Results: The median time lapse to pulpal deterioration among cases was 14.3 months. Crowns and bridge retainers had the longest interval (28 months), followed by amalgam (17.4), composite resin (11.9), and glass ionomer (11.4). Earlier deterioration was observed in teeth with restorations involving more than two surfaces (11.5), with more than two prior restorations (13.9), and with pulp exposure (6.6). In adjusted analyses, glass ionomer (HR = 1.6; 95% CI: 1.2-2.2) and multi-surface restorations (HR = 1.5; 95% CI: 1.2-1.7) were statistically significant associated variables.

Conclusions: Pulpal deterioration may occur after a median time lapse of 14.3 months following terminal restoration placement. Crowns/bridge retainers and amalgam restorations were associated with slower progression of pulpal deterioration, whereas composite resin, glass ionomer, multi-surface restorations, and pulp exposure were linked to an increased likelihood or earlier onset of pulpal deterioration.