In Vitro Infrared Thermographic Assessment of Temperature Change in the Pulp Chamber during Provisionalization: Effect of Remaining Dentin Thickness

Abstract

Interim crowns and partial fixed dental prosthesis materials generate exothermic heat during polymerization. The amount of heat transmitted to the pulp chamber can be a function of several factors, including the thickness and quality of the remaining dentin after crown preparation. The aim of this in vitro study was to measure with infrared thermography the temperature changes on the adjacent surface of the chamber roof of premolar teeth extracted from young and old patients (having different thicknesses of remaining dentin after crown preparation) during fabrication of provisional resinous restorations. Twenty extracted human first and second maxillary premolar teeth (10 from young patients, with a relatively large pulp chamber, and 10 from older patients, with a relatively small pulp chamber) were used. The roots were sectioned to expose the inner side of the chamber roof, and the crowns were provisionalized after preparation for a metal-ceramic crown. Two provisional materials, Turbo Temp 2 and Luxatemp Fluorescence, were used. Temperature changes on the inner side of the chamber roof were measured at 2-second intervals using an infrared thermal imaging camera. After completion of the temperature recordings, the teeth were sectioned and the remaining dentin thickness was determined. The older group (mean thickness: 2.82 mm) and younger group (mean thickness: 1.9 mm) differed significantly in dentin thickness ( P < 0.014 ). The mean greatest temperature increases recorded on the chamber roof of teeth with less remaining dentin were 4.07°C for Turbo Temp 2 and 3.94°C for Luxatemp Fluorescence, while increases in the premolars with greater dentin thickness were 1.69°C for Turbo Temp 2 and 1.64°C for Luxatemp Fluorescence. Significant interactions were found between tooth groups ( P < 0.000001 for Turbo Temp 2 and for Luxatemp Fluorescence). No significant differences were found between assessed materials regardless of the thickness of the remaining dentin ( P > 0.38 for the older group and P > 0.29 for the younger group). Dentin had a significant effect in limiting the temperature increase generated during polymerization of provisional materials, indicating good thermal insulating properties of this tissue. A remaining dentin thickness of 1.9 mm or more is sufficient to protect the pulp from any temperature increase during provisionalization using tested materials.

Effect of Ceramic and Dentin Thicknesses and Type of Resin-Based Luting Agents on Intrapulpal Temperature Changes during Luting of Ceramic Inlays

“…However, during cavity preparation for direct or indirect restorations, the enamel and DEJ are partially removed, and the dentin thickness is reduced according to the extent of the caries or depending on the special cavity design. Hard tissue removal during cavity preparation and several steps of the adhesive restorative procedure (i.e., polymerization of the adhesive layer and the RBC/adhesive luting agent, and the polishing procedure) may cause thermal damage due to the weakened thermal insulation effect, especially in younger patients with wider dentinal tubules [ 63 , 64 ]. The present study investigated four thicknesses (1.0 mm, 1.5 mm, 2.0 mm, and 2.5 mm) of the remaining dentin layer.…”

Increased Handpiece Speeds without Air Coolant: Aerosols and Thermal Impact

“…The result of this study indicated the most important factors affecting thermal transfer to the pulp chamber were the handpiece design and the remaining tissue thickness. The remaining dentine during tooth preparation has a clinically significant role in protecting the pulp from temperature increases (Aguiar et al 2005; Lipski et al 2020). Above 1.42 mm remaining tissue, no maximum temperature was exceeded by HSCAH-A, HSCAH-B, or the air turbine when respective water flow rates of 15 mL min −1 , 30 mL min −1 , and 23.5 mL min −1 were used.…”

Emissivity evaluation of human enamel and dentin

“…Emissivity may vary due to composition, tissue structure, surface contour (as seen with occlusal fissures and the natural curve of a whole tooth crown, compared to the flat internal surface of a tooth slice), and the tissue temperature and wavelength-collection of different thermal devices. Transfer of emissivity values, as seen in multiple articles (Lipski, 2005a;Da Costa Ribeiro, et al, 2007;Lipski, et al, 2010a;Lipski, et al, 2010b;Preoteasa, et al, 2010;Da Silva Barbosa, et al, 2013;Kilic, et al, 2013;Lipski et al, 2020;Podolak, et al, 2020), requires care, and a standardized approach to assess the emissivity of tooth tissue would be beneficial. As seen in Figure 1, a difference in emissivity can lead to large temperature differences.…”