Periodontal tissue responses after insertion of artificial crowns and fixed partial dentures

Purpose. The purpose of this review was, first, to critically evaluate publ ished evidence on the effects of artificial crowns and fixed partial dentur es (FPDs) on adjacent periodontal tissue health, and second to synthesize t his evidence into meaningful summaries. Restoration qualities that contribu te to inflammatory responses were identified based on strength of evidence, and variables that should be controlled in future investigations were outl ined. Such information is necessary to accurately predict the prognosis of peri odontal tissues adjacent to crowns or FPDs. Methods. Clinical trial and epidemiologic evidence published in English was collected. The effects of crowns or FPDs on gingival inflammation, probing depths, and bone loss were evaluated based on accuracy of measurement, rel iability of measurement, and/or appropriateness of data analysis. Results. Crowns and FPDs increased the incidence of advanced gingival infla mmation adjacent to restorations, particularly if restorations had intracre vicular finish Line placement, poor marginal adaptation, or rough surfaces. However, because of the limitation in the accuracy and reliability of prob ing depth measurements, reports of greater mean probing depths of crowned t eeth, which tended to be less than 1 mm greater than control teeth, should be questioned. Finally, crowns and FPDs in general did not accelerate the r ate of adjacent bone loss. Conclusion. Clinically deficient restorations, as well as clinically accept able restorations, can contribute to gingival inflammation. However, with t he limitations of the applied methods of measurement, current evidence has not shown an increased attachment loss adjacent to crowns or FPDs. Future t rials should document periodontal health before therapy and periodically af ter restoration insertion so that each tooth selves as its own control. In future studies, the periodontal disease history of the patient, the influen ce of the restoration on plaque formation, and the composition of the crevi cular microflora must be recorded.