Retention rate of sealant material in pits and fissures may be an invalid measure for fissure sealant effectiveness
Johannesburg (PRWEB) April 17, 2014
When dental pits and fissures are sealed then the formation of carious lesions may be prevented. The current consensus states that when a sealant is lost more quickly, carious lesions development is more likely, thus the ratio of completely retained sealants to the total number of sealants placed after a period of time is used to measure the effectiveness of fissure sealants. However, this type of measure can only be useful if it is valid. For this to be the case, sealant retention (or its loss) need to be directly associated with the absence (or development) of pit and fissure caries beyond the play of chance, regardless the type of fissure sealant placed.
The SYSTEM Initiative of the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, has evaluated the validity of loss of complete retention of dental sealants as measure for sealant effectiveness. A three-step approach was followed: Firstly, the rate of sealant retention and the occurrence of caries for the two most common sealant types - resin and glass-ionomer based sealants - were assessed. Secondly, the loss of retention of each sealant type was directly linked to the occurrence of caries on sealed teeth. Finally, the difference between the retention/caries ratios of both sealant types was tested for significance.
Suitable clinical trials were identified through a systematic literature search of main international data sources, such as the Cochrane library and PubMed/Medline, as well as regional data sources such as Scielo and InMed. Only trials with a minimum follow-up period of two years were included. Data relating to the number of teeth that had been sealed in the past and later lost sealant material and teeth that had later developed caries were recorded for analysis.
The results showed that risk of losing sealant material was significantly associated to caries when resin sealant was used, but not when using glass-ionomers. The disagreement when using glass-ionomer sealant may be explained by two points: (i) as glass-ionomer sealants fracture cohesively, remnants stay at the base of pits and fissures and may continue to offer caries prevention and (ii) the fluoride from these remnants may effect remineralistaion.
The ratios of sealant retention to caries for the two sealant types were significantly different and indicate that sealant retention is not independent from the sealant material used. For this reason, sealant retention cannot be regarded as valid measure for general sealant effectiveness.
For daily dental practice this means that the effectiveness of different sealants at preventing caries cannot be determined from their retention rate and thus is not a useful guide for selecting an effective sealant material. Instead, the ratio of caries-free teeth to the total number of sealed teeth after a period of time as direct clinical measure should be used.
The published systematic review is available in full online:
Mickenautsch S, Yengopal V. Validity of Sealant Retention as Surrogate for Caries Prevention – A Systematic Review. PLOS ONE 2013; 8: e77103