Relationship between plaque score and video-monitored brushing performance after repeated instruction--a controlled, randomised clinical trial

Abstract

Objectives: Aim of this prospective, randomised, controlled clinical trial was to use the modified bass technique (MBT) and a specific brushing sequence to investigate whether two types of instruction methods lead to differences in plaque reduction and whether plaque reduction is related to technique adoption.

Methods: Ninety-eight participants were randomly assigned to three groups: (1) control, no instruction; (2) verbal instruction by means of a leaflet; and (3) verbal instruction supported by demonstration, no leaflet. Brushing performance was video monitored. Plaque score (Turesky modified QHI (T-QHI)) was measured at baseline, afterwards participants received instructions. After 2 weeks, T-QHI was measured for a second time, and participants were re-instructed. After another 2 weeks, T-QHI was measured for a third time.

Results: At baseline, T-QHI did not differ between groups ((1) 1.99 ± 0.51, (2) 1.90 ± 0.51, (3) 1.93 ± 0.56). The second measurement revealed an improvement of T-QHI in the instructed groups and in the non-instructed control group ((1) 1.80 ± 0.47, (2) 1.58 ± 0.58, (3) 1.64 ± 0.58; n.s. between groups); in the intervention groups, remotivation achieved no further improvement ((1) 1.72 ± 0.48, (2) 1.52 ± 0.58, (3) 1.50 ± 0.69; n.s. between groups and compared to second measurement). Improvement of T-QHI was not related to proper performance of technique or brushing sequence. Those who fully adopted the brushing technique, the sequence or both did not have lower plaque scores.

Conclusion: Technical performance and effectiveness were not linked.

Clinical relevance: Within the study setting, the MBT was not effective in reducing plaque scores. The general recommendation of the MBT should be re-evaluated in further studies.