Topical anesthesia for stainless steel crown tooth preparation in primary molars: a pilot study

Placement of full-coverage restorations such as stainless steel crowns (SSCs) for pulpectomy treated primary molars is essential for successful outcomes. The tooth preparation process for SSCs can cause discomfort to gingival tissues since the crown should be seated 1 mm subgingivally. The purpose of this prospective trial was to compare the effectiveness of subgingival and transmucosal application of topical anesthetics on dental pain during SSC tooth preparation among 6- to 8-year-old children.

A consecutive sample of 27 children, aged 6-8 years, who required an SSC after pulp therapy in primary molars were randomly divided into three groups. Group A received infiltration anesthesia before tooth preparation for SSC placement, whereas in Group B and C, only topical anesthesia was applied subgingivally and transmucosally. Wong-Bakers Faces pain rating scale (WBFPS) scores were recorded after tooth preparation. Faces, Legs, Activity, Cry and Consolability (FLACC) scores were evaluated by two blinded and calibrated investigators through video recordings of the patient during tooth preparation. Data were tabulated, and inter-group comparisons were performed using the Kruskal-Wallis and analysis of variance tests.

Out of the 27 participants, 48% were boys and 52% were girls, with an overall mean age of 6.83 years. Group A showed the least pain scores according to both the scales, followed by Group B and Group C. The pain intensity was statistically significant on both the pain scales with P = 0.003 for FLACC and P < 0.001 for WBFPS.

Subgingival application of topical anesthesia reduced pain to a certain extent but not as effectively as infiltration anesthesia during SSC tooth preparation in primary molars. Transmucosal application of topical anesthesia did not reduce discomfort when compared to the other two interventions.