Emergence angles in natural anterior teeth: influence on periodontal status.

OBJECTIVES

To find the geometric values of emergence angles in human natural anterior teeth and to study their influence on periodontal status.

METHOD AND MATERIALS: Fifty anterior teeth with full-crown restorations and homologous contralateral sound teeth were examined for clinical parameters: Plaque Index, Gingival Index, probing depth, and clinical attachment loss. Impressions and stone casts were made and then separated along the midline of the teeth. All cut-surface specimens were photocopied, scanned, and transferred into graphic form with a special program. The emergence angles of both restored and natural teeth were processed and recorded. Paired t test and multivariate linear regression analysis were used for statistical analysis.

RESULTS

Mean supragingival emergence angles for facial and lingual surfaces of natural anterior teeth were 11.13 +/- 7.92 and 15.58 +/- 9.16 degrees, respectively. The corresponding values for subgingival emergence angles were 9.93 +/- 5.68 and 14.35 +/- 8.44 degrees. The periodontal parameters were higher in restored teeth than in natural teeth. When Plaque Index and gender were controlled, a correlation was shown between the lingual subgingival emergence angle of the restored teeth and probing depth. A correlation was also found between the lingual supra- and subgingival emergence angles, as well as between both angles of the restored teeth and the attachment loss.

CONCLUSION

The mean values of emergence angles obtained may aid clinicians and dental technicians in more easily designing the definitive emergence profile of restorations. The emergence profile of the restored teeth may affect periodontal status on the lingual aspect.