Soft Tissue Changes at the Pontic Sites of Cantilever Zirconia Ceramic Resin-Bonded Fixed Dental Protheses inthe Esthetic Zone: A Clinical Observational Study.

Abstract

Data on the stability of soft tissues at pontic sites of resin-bonded fixed dental protheses (RBFDP) are lacking. The purpose of this study was to evaluate soft tissue changes at pontic sites of cantilever zirconia ceramic RBFDPs with and without surgical pretreatment after different follow-up periods in the esthetic zone. Impressions were taken after the insertion of the restorations and an intraoral scan was performed at follow-up examinations. Dental casts were digitalized and superimposed with the follow-up scan. Vertical and horizontal soft tissue changes were measured buccally and lingually at mucosal margin at the central cross-section of each pontic, and for horizontal change at 1 and 2 mm below. One-way ANOVA and Kruskal-Wallis test were performed to analyze the collected data. A total of 36 pontic sites with (n = 7) and without surgical pretreatment (n = 29) were evaluated at a follow-up period of either > 4, > 6, or > 10 years (n = 12). The follow-up period had no significant effect on the tissue change. Surgical pretreatment showed significantly higher tissue loss at 2 mm below the lingual mucosal margin than for sites without surgical pretreatment. Soft tissues at pontic sites remained stable with a tissue gain at the mucosal margin up to 10 years. Based on the findings of this study, cantilever resin-bonded fixed dental protheses provide excellent functional and esthetic outcomes with preservation of soft tissues in the edentulous area of single missing incisors and a gingival sulcus-like tissue growth at the mucosal margin forming an emergence profile at pontic sites similar to that of a natural tooth.