Biomedical subjects

Haitham Al Haj

Publications and source records attributed to Haitham Al Haj.

3 recordsLinked to original sources

PubMed2003

Temperature changes induced by 809-nm GaAlAs laser at the implant-bone interface during simulated surface decontamination.

The aim of the study was to investigate temperature changes at the implant-bone interface during simulated implant surface decontamination with a 809-nm gallium-aluminium-arsenid (GaAlAs) semiconductor laser. Stepped cylinder implants with a diameter of 3.8 mm and a length of 11 mm with two different surfaces (sand-blasted and acid etched, and hydroxyapatite-coated) were inserted into bone blocks cut from freshly resected pig femurs. Access holes of 0.5 mm were drilled into the bone, to allow K-type thermocouples to contact periimplant bone in different parts of the cavity. An artificial periimplant bone defect provided access for laser irradiation in the coronal third. A 600-micrometer optic fiber was used at a distance of 0.5 mm from the implant surface. Power output varied between 0.5 and 2.5 W in the continuous wave mode. The bone block was placed into a 37 degrees C water bath in order to simulate in vivo thermal conductivity and diffusitivity of heat. Temperature elevations during irradiation were registered for a period of 120 s. In mean, the critical threshold of 47 degrees C was exceeded after 9.0 s at 2.5 W, 12.5 s at 2.0 W, 18.0 s at 1.5 W and 30.5 s at 1.0 W. Surface characteristics did not have a significant effect on temperature elevations. In an energy-dependent manner, implant surface decontamination with an 809-nm GaAlAs laser must be limited in time to allow the implant and bone to cool down. Clinical guidelines are presented to avoid tissue damage.

Acid Etching, Dental↗

PubMed2002

Effect of simulated CO2 and GaAlAs laser surface decontamination on temperature changes in Ti-plasma sprayed dental implants.

BACKGROUND AND OBJECTIVE: To investigate and compare temperature elevations at the implant-bone interface during simulated implant surface decontamination with a CO2 and a GaAlAs laser. STUDY DESIGN/MATERIALS AND METHODS: Stepped cylinder implants (Frialit 2) Friadent GmbH, Mannheim, Germany) with a Titanium plasma sprayed surface were inserted into bone blocks cut from pig femurs. An artificial periimplant bone defect provided access for laser irradiation in the coronal third. Both lasers were operated at 1.0-2.5 W in the cw-mode. The bone block was placed into a 37 degrees C water bath in order to simulate in vivo thermal conductivity and diffusitivity of heat. K-type thermocouples connected to a digital meter were used to register temperature changes at the periimplant bone. RESULTS: In mean, the critical threshold of 47 degrees C was exceeded after 8 seconds at a power output of 2.5 W, 13 seconds at 2.0 W, 18 seconds at 1.5 W, and 42 seconds at 1.0 W with the GaAlAs laser and 15 seconds (2.5 W), 23 seconds (2.0 W), 35 seconds (1.5 W), and 56 seconds (1.0 W) with the CO2 laser. At equal energy fluence, GaAlAs laser irradiation induced significantly higher temperature elevations than CO2 laser irradiation. CONCLUSIONS: In an energy dependent manner implant surface decontamination with both laser types must be limited in time to allow the implant and bone to cool down. Clinical guidelines are presented to avoid tissue damage.

Animals↗

PubMedDate not supplied

Temperature changes at the implant-bone interface during simulated surface decontamination with an Er:YAG laser.

PURPOSE: This study investigated temperature changes at the implant-bone interface during simulated implant surface decontamination with an Er:YAG laser. MATERIALS AND METHODS: Stepped cylinder implants with three different surfaces (titanium plasma sprayed, sandblasted and acid etched, and hydroxyapatite coated) were placed in bone blocks cut from freshly resected pig femurs. An artificial periimplant bone defect with a size of 6 mm2 provided access for laser irradiation in the coronal third of the implant. A 540-pm periimplantitis application tip was used at a distance of 0.5 mm from the implant surface. Pulse energy was varied between 60 and 120 mJ at 10 pps. The bone block was placed into a 37 degrees C water bath to simulate in vivo thermal conductivity and diffusitivity of heat. K-type thermocouples connected to a digital meter were used to register temperature changes at three levels of the periimplant bone. RESULTS: The temperature at the implant-bone interface did not exceed 47 degrees C after 120 seconds of continuing laser irradiation. Temperature elevations were significantly higher at the hydroxyapatite-coated implants than in the two titanium surface groups (P < .001). CONCLUSION: Decontamination of implant surfaces by means of the Er:YAG laser did not excessively heat the periimplant bone within the energy range investigated. This technique therefore seems clinically safe, at least when used with the surfaces studied.

Acid Etching, Dental↗