In vitro pulp chamber temperature rise during composite resin polymerization with different curing lights.

The damaging effect of temperature increase on the pulp tissue during restorative treatment has been a matter of concern in dentistry for many years. Aesthetic restorative dentistry relies on polymerization of light-activated resin composites which can cause damaging effects to the dental pulp as a result of temperature rise caused by both the exothermic reaction process and the energy absorbed during irradiation. This in vitro study was carried out to measure the increase in pulp chamber temperature induced during composite resin-polymerization with various light curing units in three different and common clinical situations (Veneer, Class II, Class III) and the clinical implications of the results. Measurement of pulp temperature changes during polymerization was performed with a Al-Cr Thermocouple positioned at the pulp-dentin junction. Mean values were calculated from six measurements with each light curing unit.

Effects of elevated temperatures on various restorative materials: an in vitro study.

In cases of mass disasters associated with fire, identification of the burnt victims can be a real challenge to the forensic team. Teeth and their restorations play a significant role to aid in the identification process, as various restorative materials have varying resistance to high temperatures. A study was undertaken to evaluate the changes taking place on teeth restored with amalgam, composites, glass ionomers, heat cure acrylic, and ceramics. The specimens were placed in a furnace and heated to predetermined temperatures of 200, 400, 600, 800, and 1000 degrees C and the changes were examined using a digital camera and stereomicroscope. Our observations show that while some restorations were able to withstand elevated temperatures, others were reduced to an unrecognizable mass at relatively low temperatures.

Prevention of caries by pulsed CO2 laser pre-treatment of enamel: an in-vitro study.

The aim of the study was to assess the caries inhibitory potential of carbon dioxide laser and explore the effect of the number of pulses used to correlate caries inhibition. Caries free human mandibular molars were irradiated with carbon-dioxide laser of wavelength 10.6 microm at 5, 15, 25, 50 and 100 pulses. Simulated caries lesions were allowed to form by immersing the teeth in artificial caries medium for three weeks. Thin sections of 75 microns were obtained by using hard tissue microtome. These sections were observed under polarizing microscope, caries lesions were identified and their depth was measured. These values were subjected to statistical analysis. The results showed that carbon-dioxide laser irradiation can inhibit caries like lesion upto 82.7% and it was optimal at 25 pulses.