Connective Tissue Attachment Invasion Frequency in Deep Interproximal Conservative Direct Restorations: a Preliminary Report of an Ongoing Cross-Sectional Study

Deep interproximal direct restorations may be difficult to manage from a clinical point of view and potentially impinge on periodontal tissue stability. This study reports on connective attachment invasion frequency in deep interproximal conservative direct restorations. 124 sites of 38 consecutive patients in need of interproximal restorations were evaluated. Premolars and molars teeth without previous endodontic treatment with deep interproximal carious lesions involving ± 1mm of CEJ were considered. Periodontal and inflammatory parameters were recorded at each site (PPD, CAL, BOP, PI, KG). Under local anesthesia, crestal probing (MG - BC) and the distance from the apical margin of the preparation to the bone crest (PM - BC) were recorded. Clinical and radiographic quality control assessments were carried out upon completion of the restoration. The estimated connective attachment (CTA) dimension was calculated by subtracting periodontal probing depth (PPD) from crestal probing depth (SC). By comparing this value with the location of the restorative margin with respect to the gingival margin (MG), it was possible to determine whether or not the restoration was impinging on the connective tissue area. Only 3% of the restorations were found to be within the dimension of the CTA. If only subgingival margins were considered, the frequency of CTA violation would be 13.5%. This preliminary data from this ongoing study may help better define the indications for clinical crown lengthening procedures to avoid connective tissue attachment violation.