Table 3: Studies that investigated the effect of preheating resin composites on micro leakage in class II and V, degree of conversion, mechanical properties, polymerization shrinkage, hardness and marginal adaptation.

First author
+ Year
Temperature Variables tested Results
Aksu, M.N
[43] (2004).
130°C Micro leakage in Class II composite Preheating of the composite investigated resulted in significantly less micro leakage at the cervical margin compared to the control or the use of the corresponding flowable resin.
Darnoch, M [44]
Between 3°C and 60 °C Monomer conversion and duration of light exposure Pre-heating composite prior to photoactivation provides greater conversion requiring reduced light exposure than with room-temperature composite.
Wagner, W.C [45]
54.4°C Micro leakage in Class II composite restorations Preheating the composite resulted in significantly less micro leakage at the cervical margins compared to the flowable liner and control.
Walter, R [46]
37°C, 54°C, or 68°C Polymerization shrinkage Preheating composite to relatively high temperatures (54°C or 68°C) to increase its flow and adaptation causes an increase in volumetric shrinkage
Lohbauer, U [47]
Between 10°C. and 68 °C. Degree of conversion Pre-heating of resin composites does not increase degree of conversion over time. Polymerization shrinkage as a function of pre-heating temperatures exhibited a linear correlation after 5 min, but no statistically different behavior after 24 h.
Lucey, S [48]
60 °C Pre-cured viscosity and post-cured surface hardness Pre-heating resin composite reduces its pre-cured viscosity and enhances its subsequent surface hardness.
Fróes-Salgado, N.R [49]
68 °C Marginal adaptation (MA), degree of conversion (DC), flexural strength (FS), and polymer cross-linking (PCL) The pre-heated composite showed better MA than the room-temperature groups. Composite pre-heating and energy density did not affect the DC, FS and PCL.
Tantbirojn, D [50]
68°C Hardness and postgel shrinkage Preheating of the composites only slightly increased hardness values and did not negatively affect postgel shrinkage.
Deb, S [51]
22 °C and 60 °C. Flow and marginal
Pre-warming of the composites studied enhanced flow as observed by measuring film thickness and did not significantly affect other properties.
Dos Santos, R.A
[52] 2011
23°C, 54°C and 60°C Micro leakage in Class II cavities restored with dental composite Preheating the resin composite did not improve the micro leakage means when high-irradiance LED was used; however, it decreased the micro leakage means when a QTH with low irradiance was used.
Nada, K [53]
37°C and 54°C Mechanical properties Pre warming significantly improved surface hardness and bulk properties of the composites; however, this improvement was significant in only some of the tested materials.
Karaarslan, E.S [54] (2012) 37°C, 54°C and 68°C Micro leakage
in Class V cavities
No significant differences among the preheated groups.