ABSTRACT
PROBLEM: Laser systems are known to raise pulpal temperatures when applied to tooth surfaces. Dental biocalcified tissues can be cut with an erbium,chromium:yttrium-scandium-gallium-garnet laser-powered hydrokinetic system. This device is effective for caries removal and cavity preparation in vitro. Pulpal monitoring of temperature changes during hard tissue cutting by a hydrokinetic system have not been reported. OBJECTIVES: This study compared the effects of hydrokinetic system, dry bur, and wet bur tooth cutting on pulpal temperature. STUDY DESIGN: In vivo thermocouple intrapulpal measurements were made on cuspid teeth in anesthetized beagle dogs. In vitro measurements were made on extracted human molar teeth preserved in high-salt solution and later rinsed in phosphate-buffered saline (pH 7.4) to simulate in vivo conditions. The hydrokinetic system was compared with conventional air-turbine-powered bur cutting. The hydrokinetic system cuts and bur preparations were randomly made on the buccal surfaces at the cervical one third of the crown and extended until exposure of the pulp was confirmed clinically. RESULTS: Pulpal temperatures associated with the hydrokinetic system either showed no change or decreased by up to 2 degrees C. Wet bur preparations resulted in a 3 degrees to 4 degrees C rise. With dry bur preparations, a 14 degrees C rise in temperature was recorded. CONCLUSIONS: Under the conditions of this study, the erbium,chromium:yttrium-scandium-gallium-garnet laser-powered hydrokinetic system, when used for cavity preparation, had no apparent adverse thermal effect as measured in the pulp space.
Subject(s)
Body Temperature/physiology , Dental Cavity Preparation/methods , Dental Pulp/physiology , Laser Therapy/methods , Aluminum Silicates , Animals , Chromium , Cuspid/surgery , Dental Caries/surgery , Dental Cavity Preparation/instrumentation , Dental High-Speed Equipment , Dentistry, Operative/instrumentation , Dogs , Equipment Design , Erbium , Gallium , Humans , Laser Therapy/instrumentation , Lasers , Molar/surgery , Scandium , Thermometers , Tooth Cervix/surgery , Tooth Crown/surgery , YttriumABSTRACT
The near red-pulsed erbium, chromium:yttrium-scandium-gallium-garnet laser hydrokinetic system, or Er,Cr:YSGG laser HKS, is effective in cutting dental hard tissues. In this longitudinal study, the authors studied the continuously erupting open-apex incisors of New Zealand albino rabbits and the constricted apex teeth of beagles to determine the effects of HKS-produced lesions at various energy levels and of preparations produced by a tapered fissure bur on dental pulp. No pulpal inflammatory responses could be identified either immediately or 30 days after surgery in HKS preparations that removed enamel and dentin without pulp exposure.
Subject(s)
Dental Cavity Preparation/methods , Dental Pulp/anatomy & histology , Laser Therapy , Aluminum Silicates , Animals , Bicuspid , Chromium , Connective Tissue/pathology , Dental Cavity Preparation/instrumentation , Dental Enamel/surgery , Dental Enamel/ultrastructure , Dental Pulp Exposure/pathology , Dental Pulp Necrosis/pathology , Dentin/surgery , Dentin/ultrastructure , Dentin, Secondary/pathology , Dogs , Erbium , Gallium , Incisor , Longitudinal Studies , Molar , Odontoblasts/pathology , Pulpitis/pathology , Rabbits , Scandium , Tooth Apex/anatomy & histology , Tooth Eruption , Yttrium , Zinc Oxide-Eugenol Cement/administration & dosageABSTRACT
OBJECTIVES: Lasers are effective tools for soft tissue surgery. The erbium, chromium: yttrium, scandium, gallium, garnet laser is a new system that incorporates an air-water spray. This study evaluates the cutting margins of this laser and compares healing with laser and conventional scalpel and punch biopsy-induced wounds. STUDY DESIGN: New Zealand white rabbits were divided into serial sacrifice groups; the tissues were grossly and microscopically analyzed after laser and convential steel surgical wounding. RESULTS: Wound margins were found to show minimal edge coagulation artifact and were 20 to 40 mm in width. Laser wounds showed minimal to no hemorrhage and re-epithelialization and collagenization were found to occur by day 7 in both laser and conventional groups. CONCLUSIONS: The new laser system is an effective soft tissue surgical device; wound healing is comparable to that associated with surgical steel wounds. The minimal edge artifact observed with this laser system should allow for the procurement of diagnostic biopsy specimens.
