Pattern of healing of calvarial bone in the rat following application of the erbium-YAG laser.
OBJECTIVE
The aim of this study was to examine the pattern of healing in rat calvarial defects prepared with the erbium-YAG laser, using the "guided tissue regeneration" technique [Dahlin et al., Scand J Plast Reconstr Hand Surg 1990;24: 13-19].


METHODS
PTFE membranes were placed over the lased skull defects and the skin wounds sutured. Rats were killed humanely at intervals after surgery and the skulls processed for paraffin wax histology. A further group of mature rats was killed humanely and the calvariae removed. Slots were prepared using the erbium-YAG laser and immediately examined under the environmental scanning electron microscope (ESEM) in hydrated conditions, which avoided drying artefact.


RESULTS
An amorphous, mineral-rich carbon layer surrounds the lased bone defect, which in the in vivo experiments was seen as a basophilic zone that was resistant to resorption.


CONCLUSIONS
Bone infilling of the lased defect was retarded by delayed resorption of the amorphous, mineral-rich carbon layer.
el Montaser
M A
MA
Department of Dental Medicine and Surgery, University Dental Hospital of Manchester, England.
Devlin
H
H
Sloan
P
P
Dickinson
M R
MR
D000818:Animals; D015519:Bone Density / Q000502:physiology; D001861:Bone Regeneration / Q000502:physiology; D001862:Bone Resorption / Q000473:pathology; D006097:Granulation Tissue / Q000473:pathology; D053685:Laser Therapy / Q000295:instrumentation*; D008855:Microscopy, Electron, Scanning; D051381:Rats; D017207:Rats, Sprague-Dawley; D012886:Skull / Q000473:pathology / Q000601:surgery*; D014945:Wound Healing / Q000502:physiology*