Immunohistochemical characterization of periodontal wound healing following nonsurgical treatment with fluorescence controlled Er:YAG laser radiation in dogs

BACKGROUND AND OBJECTIVE: The aim of the present study was to immunohistochemically characterize periodontal wound healing following nonsurgical treatment with fluorescence controlled Er:YAG laser radiation in dogs. STUDY DESIGN/MATERIALS AND METHODS: Five beagle dogs suffering from naturally occurring chronic periodontitis were randomly allocated in a split-mouth design to nonsurgical periodontal treatment using either (a) an Er:YAG laser at 10.2, 12.8, 15.4, 18, and 20.4 J/cm2 (ERL1-5), or (b) an ultrasonic device (VUS) serving as control. The animals were sacrificed after 3 months. Histomorphometrical (e.g. inflammatory cell infiltrate, surface changes, cementum formation), and immunohistochemical parameters (collagen type I, CD68, matrix metalloproteinase (MMP)-8) were assessed. RESULTS: Inflammatory cell infiltrates of different extent were commonly observed in all treatment groups. However, histomorphometrical analysis revealed new cementum formation with inserting collagen type I fibers along the instrumented root surfaces in most specimens of both ERL (ERL2: 31+/-81 to ERL5: 595+/-575 microm) and VUS (50+/- 215 microm) groups. This was associated with pronounced CD68 and weak MMP-8 antigen reactivity. CONCLUSION: Within the limits of the present study, it was concluded that both treatment procedures (i) were effective in controlling inflammatory cell infiltrates, and (ii) may support the formation of a new connective tissue attachment.