Restor Dent Endod.  2019 Nov;44(4):e41. 10.5395/rde.2019.44.e41.

The effect of preheating resin composites on surface hardness: a systematic review and meta-analysis

• Elkaffas A
• Eltoukhy R
• Elnegoly S
• Mahmoud SH

• KMID: 2463469
• DOI: http://doi.org/10.5395/rde.2019.44.e41

Abstract

OBJECTIVES
This paper presents a systematic review and meta-analysis of the effect of preheating on the hardness of nanofilled, nanoceramic, nanohybrid, and microhybrid resin composites.
MATERIALS AND METHODS
An electronic search of papers on MEDLINE/PubMed, ScienceDirect, and EBSCOhost was performed. Only in vitro studies were included. Non-English studies, case reports, clinical trials, and review articles were excluded. A meta-analysis of the reviewed studies was conducted to quantify differences in the microhardness of the Z250 microhybrid resin composite using the Comprehensive Meta-Analysis software.
RESULTS
Only 13 studies met the inclusion criteria for this systematic review. The meta-analysis showed that there were significant differences between the non-preheated and preheated modes for both the top and bottom surfaces of the specimens (p < 0.05). The microhardness of the Z250 resin composite on the top surface in the preheated mode (78.1 ± 2.9) was higher than in the non-preheated mode (67.4 ± 4.0; p < 0.001). Moreover, the microhardness of the Z250 resin composite on the bottom surface in the preheated mode (71.8 ± 3.8) was higher than in the non-preheated mode (57.5 ± 5.7, p < 0.001).
CONCLUSIONS
Although the results reported in the reviewed studies showed great variability, sufficient scientific evidence was found to support the hypothesis that preheating can improve the hardness of resin composites.

Keyword

Composite temperature; Meta-analysis; Microhardness; Microhybrid; Preheated composite; Systematic review

MeSH Terms

Hardness*
In Vitro Techniques