Dental fillings for the treatment of caries in the primary dentition

Childhood caries (tooth decay) consists of a form of tooth decay that affects the milk teeth (also known as baby or primary teeth) of children. This may range from tooth decay in a single tooth to rampant caries affecting all the teeth in the mouth. Primary teeth in young children are vital to their development and every effort should be made to retain these teeth for as long as is possible. Dental fillings or restorations have been used as an intervention to repair these damaged teeth. Oral health professionals need to make astute decisions about the type of restorative (filling) material they choose to best manage their patients with childhood caries. This decision is by no means an easy one as remarkable advances in dental restorative materials over the last 10 years has seen the introduction of a multitude of different filling materials claiming to provide the best performance in terms of durability, aesthetics, symptom relief, etc when placed in the mouth. This review sought to compare the different types of dental materials against each other for the same outcomes.

The objective of this review was to compare the outcomes (including pain relief, survival and aesthetics) for restorative materials used to treat caries in the primary dentition in children. Additionally, the restoration of teeth was compared with extraction and no treatment.

Electronic searches of the following databases were undertaken: the Cochrane Oral Health Group's Trials Register (up to January 2009); CENTRAL (The Cochrane Library 2009, Issue1); MEDLINE (1966 to January 2009); EMBASE (1996 to January 2009); SIGLE (1976 to 2004); and conference proceedings on early childhood caries, restorative materials for paediatric dentistry, and material sciences conferences for dental materials used for children's dentistry (1990 to 2008). The searches attempted to identify all relevant studies irrespective of language.Additionally, the reference lists from articles of eligible papers were searched, handsearching of key journals was undertaken, and personal communication with authors and manufacturers of dental materials was initiated to increase the pool of suitable trials (both published and unpublished) for inclusion into this review.

Randomised controlled trials (RCTs) or quasi-randomised controlled trials with a minimum period of 6 months follow up were included. Both parallel group and split-mouth study designs were considered. The unit of randomisation could be the individual, group (school, school class, etc), tooth or tooth pair. Included studies had a drop-out rate of less than 30%. The eligible trials consisted of young children (children less than 12 years) with tooth decay involving at least one tooth in the primary dentition which was symptomatic or symptom free at the start of the study.

Data were independently extracted, in duplicate, by two review authors. Disagreements were resolved by consultation with a third review author. Authors were contacted for missing or unclear information regarding randomisation, allocation sequence, presentation of data, etc. A quality assessment of included trials was undertaken. The Cochrane Collaboration statistical guidelines were followed for data analysis.

Only three studies were included in this review. The Fuks 1999 study assessed the clinical performance of aesthetic crowns versus conventional stainless steel crowns in 11 children who had at least two mandibular primary molars that required a crown restoration. The outcomes assessed at 6 months included gingival health (odds ratio (OR) 0.3; 95% confidence interval (CI) 0.01 to 8.32), restoration failure (OR 3.29; 95% CI 0.12 to 89.81), occlusion, proximal contact and marginal integrity. The odds ratios for occlusion, proximal contact and marginal integrity could not be estimated as no events were recorded at the 6-month evaluation. The Donly 1999 split-mouth study compared a resin-modified glass ionomer (Vitremer) with amalgam over a 36-month period. Forty pairs of Class II restorations were placed in 40 patients (21 males; 19 females; mean age 8 years +/- 1.17; age range 6 to 9 years). Although the study period was 3 years (36 months), only the 6- and 12-month results are reported due to the loss to follow up of patients being greater than 30% for the 24- and 36-month data. Marks 1999a recruited 30 patients (age range 4 to 9 years; mean age 6.7 years, standard deviation 2.3) with one pair of primary molars that required a Class II restoration. The materials tested were Dyract (compomer) and Tytin (amalgam). Loss to follow up at 24 and 36 months was 20% and 43% respectively. This meant that only the 24-month data were useable. For all of the outcomes compared in all three studies, there were no significant differences in clinical performance between the materials tested.No studies were found that compared restorations versus extractions or no treatment as an intervention in children with childhood caries.

It was disappointing that only three trials that compared three different types of materials were suitable for inclusion into this review. There were no significant differences found in all three trials for all of the outcomes assessed. Well designed, randomised controlled trials comparing the different types of filling materials for similar outcomes are urgently needed in dentistry. There was insufficient evidence from the three included trials to make any recommendations about which filling material to use.