Fracture strength of restorations in proximal cavities of primary molars

The assessment of internal adaptation and fracture resistance of glass ionomer and resin-based restorative materials applied after different caries removal techniques in primary teeth: an in-vitro study

Background

The aim of this study was to evaluate the 3-dimensional (3D) internal adaptation (IA) and fracture resistance (FR) of compomer and glass ionomers applied after conventional caries removal to sound dentin (CCRSD) and selective caries removal to firm dentin (SCRFD) in in-vitro.

Methods

Thirty extracted primary molars were randomly assigned to three main groups (n = 10) as glass hybrid restorative (GHR) (Equia Forte® HT), conventional glass ionomer (CGIR) (Voco Ionofil Molar) and compomer (Dyract XP). Each group was randomly divided into two subgroups according to caries removal technique as CCRSD (n = 5) and SCRFD (n = 5). The restoration procedures were completed after caries removal (CCRSD or SCRFD) in all samples. Then, specimens were subjected to IA and FR tests. Data were analyzed with Student’s t, one-way ANOVA, and Kruskal Wallis-H tests. The correlation between IA and FR results was analyzed with a Pearson test. The statistical significance level was considered as 5%.

Results

While CCRSD showed superior IA results than SCRFD for all restorative materials (p < 0.05), no statistical difference was found between CCRSD and SCRFD in FR assessment (p > 0.05). In CCRSD, compomer showed superior results for IA and FR than glass ionomers (p < 0.05). In SCRFD, it was found no significant difference between the restoratives for IA (p > 0.05). However, compomer showed superior FR results than glass ionomers (p < 0.05). There was moderate negative correlation between internal voids and FR without statistically significant difference (r = −0.333, p = 0.072).

Conclusions

Despite the advantages of SCRFD, it was found to be less superior than CCRSD in IA assessment. Therefore, when SCRFD is preferred, a peripheral seal should be provided for ideal restorative treatment. On the other hand, compomer mostly showed superior results compared to others.

One-year clinical evaluation of two high-viscosity glass-ionomer cements in class II restorations of primary molars

BACKGROUND

Little information exists on the clinical performance of restorative materials on primary teeth of preschool children. This study aimed to evaluate clinical performance of compomer, glass-hybrid-added high-viscosity glass-ionomer cement and zinc-added high-viscosity glass-ionomer cement materials in class ΙΙ restorations of primary molars.

METHODS

The study included 251 teeth of 57 patients aged 4-7 years with proximal caries in primary molars. The teeth were divided into three groups, and each restorative material was randomly distributed. Dyract XP, Equia Forte and ChemFil Rock materials were placed after cavity preparation and clinically evaluated at 3, 6, 9 and 12 months using modified United States Public Health Service criteria. Statistical analyses were performed using chi-square and z tests.

RESULTS

At the end of 12 months, a total of three restorations in Dyract XP group, 22 in Equia Forte group and 11 in ChemFil Rock group failed in retention criteria. No statistically significant difference existed between retention, colour match and surface texture criteria of all groups at 3 and 6 months, but a statistically significant difference was found at 12 months (P < 0.05).

CONCLUSION

For class ΙΙ restorations of primary molars, the success of compomer material was superior to high-viscosity glass-ionomer materials.

Success rate of proximal tooth-coloured direct restorations in primary teeth at 24 months: a meta-analysis

The aim was to determine the survival of tooth-coloured restorative materials in proximal restorations of primary teeth at 24 months of follow-up and the influence of the following variables: use of coating, use of cavity conditioner, use of rubber dam isolation, the cavity form, the dentist's experience and the methodological characteristics of the studies. We conducted a search until May 2019, obtaining 16 articles from which 30 independent studies were extracted, which were considered as units of analysis. Four outcome measures were extracted from each study: retention, marginal integrity, anatomic form, and absence of recurrent caries. Separate meta-analyses were carried for each outcome and multiple meta-regression model was applied. The outcomes with the highest mean success rates were absence of recurrent caries and anatomic form. The type of material significantly influenced success rates. The best materials were resin-based material plus total-etching adhesion and resin-modified glass ionomer cement (RMGIC), and the worst high viscosity glass ionomer cement (HVGIC). Atraumatic restorative treatment (ART) had a lower success rate than the conventional cavity form. RMGIC had the best clinical performance and HVGIC the worst. The form of the cavity, blinding and the experience of the operator were the variables that influenced success rates. Proximal primary molar restorations should be performed with RMGIC as it combines good mechanical performance of the resins together with the prevention of secondary caries of glass ionomers.