title: Laser induced molar tooth pulp chamber temperature changes.
abstract: Temperature changes in enamel tissue and the pulp chamber under the influence of a CO2 laser were measured by direct methods in vitro. X-ray diffraction analysis revealed alpha-Ca3(PO4), the high-temperature modification of enamel hydroxyapatite, thus indicating that the enamel melting temperature was above 1,000 degrees C in the interaction area of laser (continuous wave, 15 s exposure time, 1 mm spot size) and tissue. Powers of 0.5 and 1 W (continuous wave), 1.5 mm spot size, and 10 s exposure time vaporize and carbonize dentin tissue at the cavity bottom of class I preparation molars. The observed temperature rise of 4 degrees C indicates that thermal injury to the pulp tissue does not occur.
authors.affiliation: Department of Dental Pathology, University of Zagreb Dental School, Croatia.
authors.forename: I
authors.initials: I
authors.lastname: Anić
authors.forename: D
authors.initials: D
authors.lastname: Vidović
authors.forename: M
authors.initials: M
authors.lastname: Luić
authors.forename: M
authors.initials: M
authors.lastname: Tudja
mesh_terms: D001831:Body Temperature / Q000528:radiation effects; D002130:Calcium Phosphates / Q000528:radiation effects; D002245:Carbon Dioxide; D003737:Dental Cavity Preparation; D003743:Dental Enamel / Q000528:radiation effects* / Q000648:ultrastructure; D003786:Dental Pulp Cavity / Q000502:physiology / Q000528:radiation effects* / Q000648:ultrastructure; D003804:Dentin / Q000528:radiation effects* / Q000648:ultrastructure; D017886:Durapatite; D006801:Humans; D006882:Hydroxyapatites / Q000528:radiation effects; D007834:Lasers; D008855:Microscopy, Electron, Scanning; D008963:Molar; D013997:Time Factors; D014961:X-Ray Diffraction
chemical_list: D002130:Calcium Phosphates; D006882:Hydroxyapatites; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; D002245:Carbon Dioxide; C485838:calcium phosphate, monobasic, anhydrous; D017886:Durapatite; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous