The modified Ottawa method to establish the update need of a systematic review: glass-ionomer versus resin sealants for caries prevention

Caries-Preventive Effect of High-Viscosity Glass Ionomer and Resin-Based Fissure Sealants on Permanent Teeth: A Systematic Review of Clinical Trials

BACKGROUND

Glass-ionomers are traditionally regarded to be inferior to resin as fissure sealants in protecting teeth from dental caries, due to their comparatively lower retention rate. Unlike low-viscosity glass-ionomers, high-viscosity glass-ionomer cements (HVGIC) are placed as sealants by pressing the material into pits and fissures with a petroleum-jelly-coated index finger. Hence, HVGIC sealants are assumed to penetrate pits and fissures deeper, resulting in a higher material retention rate, which may increase its caries-preventive effect.

METHODS

The aim of this review was to answer the question as to whether, in patients with fully erupted permanent molar teeth, HVGIC based fissure sealants are less effective to protect against dental carious lesions in occlusal pits and fissures than resin-based fissure sealants? A systematic literature search in eight databases was conducted. Heterogeneity of accepted trials and imprecision of the established evidence were assessed. Extracted sufficiently homogenous datasets were pooled by use of a random-effects meta-analysis. Internal trial validity was evaluated. The protocol of this systematic review was registered with the International Prospective Register of Systematic Reviews (PROSPERO / Nr.: CRD42015016007).

RESULTS

Seven clinical trials were provisionally included for further review. Of these, one was excluded. Seven trial reports reporting on six trials were accepted. From these, 11 datasets were extracted and pooled in four meta-analyses. The results suggest no statistically significant differences after up to 48 months and borderline significant differences in favour of HVGIC sealants after 60 months (RR 0.29; 95% CI: 0.09-0.95; p = 0.04 / RD -0.07; 95% CI: -0.14, -0.01). The point estimates and upper confidence levels after 24, 36, 48 and 60 months of RR 1.36; RR 0.90; RR 0.62; RR 0.29 and 2.78; 1.67; 1.21; 0.95, respectively, further suggest a chronological trend in favour of HVGIC above resin-based sealants. The internal trial validity was judged to be low and the bias risk high for all trials. Imprecision of results was considered too high for clinical guidance.

CONCLUSION

It can be concluded that: (i) Inferiority claims against HVGIC in comparison to resin-based sealants as current gold-standard are not supported by the clinical evidence; (ii) The clinical evidence suggests similar caries-preventive efficacy of HVGIC and resin-based sealants after a period of 48 months in permanent molar teeth but remains challenged by high bias risk; (iii) Evidence concerning a possible superiority of HVGIC above resin-based sealants after 60 months is poor (even if the high bias risk is disregarded) due to imprecision and requires corroboration through future research.

Moderate quality evidence finds statistical benefit in oral health for powered over manual toothbrushes

DATA SOURCES

The Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, CINAHL, National Institutes of Health Trials Register and the WHO Clinical Trials Registry Platform for ongoing trials. Reference lists of identified articles were also scanned for relevant papers. Identified manufacturers were contacted for additional information.

STUDY SELECTION

Only randomised controlled trials comparing manual and powered toothbrushes were considered. Crossover trials were eligible for inclusion if the wash-out period length was more than two weeks.

DATA EXTRACTION AND SYNTHESIS

Study assessment and data extraction were carried out independently by at least two reviewers. The primary outcome measures were quantified levels of plaque or gingivitis. Risk of bias assessment was undertaken. Standard Cochrane methodological approaches were taken. Random-effects models were used provided there were four or more studies included in the meta-analysis, otherwise fixed-effect models were used. Data were classed as short term (one to three months) and long term (greater than three months).

RESULTS

Fifty-six trials were included with 51 (4624 patients) providing data for meta-analysis. The majority (46) were at unclear risk of bias, five at high risk of bias and five at low risk. There was moderate quality evidence that powered toothbrushes provide a statistically significant benefit compared with manual toothbrushes with regard to the reduction of plaque in both the short and long-term. This corresponds to an 11% reduction in plaque for the Quigley Hein index (Turesky) in the short term and a 21% reduction in the long term. There was a high degree of heterogeneity that was not explained by the different powered toothbrush type subgroups.There was also moderate quality evidence that powered toothbrushes again provide a statistically significant reduction in gingivitis when compared with manual toothbrushes both in the short and long term. This corresponds to a 6% and 11% reduction in gingivitis for the Löe and Silness indices respectively. Again there was a high degree of heterogeneity that was not explained by the different powered toothbrush type subgroups. The greatest body of evidence was for rotation oscillation brushes which demonstrated a statistically significant reduction in plaque and gingivitis at both time points.

CONCLUSIONS

Powered toothbrushes reduce plaque and gingivitis more than manual toothbrushing in the short and long term. The clinical importance of these findings remains unclear. Observation of methodological guidelines and greater standardisation of design would benefit both future trials and meta-analyses. Cost, reliability and side effects were inconsistently reported. Any reported side effects were localised and only temporary.