# Associations Between Restoration Margins and Adjacent Periodontal Status—Longitudinal Results From SHIP‐TREND

## TL;DR

This study shows that dental restorations, especially crowns, are linked to worse periodontal health over seven years in a population-based cohort.

## Contribution

The study provides longitudinal evidence of the adverse impact of dental restorations on periodontal outcomes.

## Key findings

- Crowns had the greatest negative impact on periodontal health compared to filled or sound surfaces.
- Periodontal outcomes like bleeding on probing and probing depth were worse near restored surfaces.
- Results remained consistent even when accounting for incidentally placed restorations.

## Abstract

To investigate the association between dental restorations and adjacent periodontal status over a 7‐year period, using data from a population‐based cohort study.

We used 7‐year follow‐up data on the restorative and periodontal statuses of 88,793 tooth surfaces from 2158 SHIP‐TREND (Study of Health in Pomerania) participants. Using confounder‐adjusted and inverse‐probability‐weighted generalised estimating equations, we estimated the associations of restoration status with bleeding on probing (BOP), probing depth (PD) and clinical attachment level (CAL).

Surfaces with dental restorations had significantly poorer periodontal outcomes than sound surfaces, with crowns having the greatest impact. At follow‐up, filled and crowned surfaces presented higher proportions of adjacent sites with BOP (18.5% and 22.4%, respectively) compared to sound surfaces (15.8%). Similarly, adjusted average PD was 1.93 mm adjacent to sound surfaces, 1.99 mm adjacent to surfaces with fillings and 2.14 mm adjacent to surfaces with crowns. The results remained consistent when the effects of incidentally placed fillings and crowns on follow‐up periodontal status were evaluated. Although effect modification by surface type was observed, no consistent patterns emerged across the different outcomes.

Dental restorations can have an adverse effect on periodontal health, emphasising the critical need for precise restorative techniques and post‐treatment maintenance.