Prevention of root caries in Chinese institutionalized elders

Abstract

OBJECTIVES: To compare the effectiveness of four methods in preventing new active root caries. METHODS: This study was a randomized controlled trial on institutionalized elders aged 60-89 years in Hong Kong. A baseline examination was conducted on elders in 21 elderly homes. Status of their tooth roots was recorded. Generally healthy institutionalized elders with at least 5 teeth with exposed sound root surfaces were randomly allocated into one of four prevention groups: Group 1 - receiving individualized oral hygiene instruction (OHI) only; Group 2 - OHI and applications of chlorhexidine varnish every 3 months; Group 3 - OHI and applications of sodium fluoride varnish every 3 months; and Group 4 - OHI and annual applications of silver diamine fluoride solution. Status of their root surfaces was assessed annually by a masked independent examiner.

RESULTS: 306 elders were examined at the baseline. After three years, 203 elders (66%) were reviewed. The mean numbers of root surfaces with new caries found at the three-year examination in Groups 1, 2, 3 and 4 were 1.85, 0.69, 0.06, and 0.18, respectively (ANOVA, p<0.001). Elders receiving only OHI developed more new root caries surfaces (Scheff's multiple-comparison, p<0.05) than the elders in the silver diamine fluoride solution, sodium fluoride or chlorhexidine varnish groups. Three elders have to be treated with silver diamine fluoride solution, sodium fluoride or chlorhexidine varnish to prevent one elder from developing root caries (number needed to treat (NNT) silver diamine fluoride = 3, 95%CI 2-4; NNT sodium fluoride = 3, 95%CI 2-3; NNT chlorhexidine = 3, 95%CI 2-6).

CONCLUSIONS: Silver diamine fluoride solution, sodium fluoride and chlorhexidine varnish were found to be more effective than OHI only in preventing new root caries in institutionalized elders over three years.