Axial Contour Alteration following Restorative Treatment: A Systematic Review

Purpose: This qualitative systematic review had two aims: (1) evaluation of the impact of restorative treatment on tooth contour, and (2) investigation of the effect of altered tooth contour on biological health. Methods: An electronic search was conducted using PubMed (MEDLINE), Cochrane Library and Google Scholar. A combination of relevant key words was applied. The search was completed in October 2015 and was confined to peer-reviewed studies published in English. Results: The initial search had disclosed a total of 1057 studies; however, after applying the inclusion criteria, only 12 studies were suitable for inclusion. The studies had revealed that the axial tooth contour is vulnerable to increasing following restorative treatment. The axial contour tends to increase gradually as the distance from the gingival margin increases. Still, the contour increase was within the anatomical range. There were signs that increased tooth contour was associated with negative biological consequences. However, a clear relationship between contour increase and the biological consequences was not apparent. There were indications that the observed negative consequences may be related to restorative variables such as plaque retentiveness and subgingival margin placement. Conclusions: As the contour increase appears to be very likely to occur after restorative treatment, and the negative biological consequences cannot be solely attributed to the contour increase, it can be concluded that reasonable contour alteration is acceptable. The key factors that will reduce the negative consequences are cleansability and the maintenance of a healthy restoration-soft tissue relationship.