Peri-implant Defect Morphology and Temperature Changes During Er,Cr:YSGG-Laser Decontamination

Objectives: The architecture of the peri-implant defect may affect how residual heat associated with laser irradiation is disseminated. The aim of this study was to assess the influence of intra-bony defect morphology on temperature change (ΔT) of irradiated implants using an Er,Cr:YSGG laser.
Methods: Five separate defects (circumferential, one-walled, two-walled, three-walled or horizontal defect) were created around dental implants that were placed into a synthetic (bovine) bone analog that mimics type II quality bone. Each implant surface and the surrounding bone were irradiated by a non-contact Er,Cr:YSGG laser (2W power; free-running pulsed) for 30 and 60 seconds. Apical and coronal thermocouples placed in contact with implants were used to evaluate ΔT at 30 and 60 seconds. Statistical comparison was performed using statistical software. The means of (ΔT) during irradiation were compared between the five experimental groups using ANOVA models.
Results: The most substantial temperature differences of the coronal and apical thermocouple were observed in the 2- and 3-wall defects as follows: 2-wall defect ΔT (at 30s 2.88±0.35 coronal and 2.27±0.20 apical; at 60s 3.58±0.41 coronal and 2.65±0.16 apical); 3-wall defect ΔT (at 30s 2.89±0.43 coronal and 2.29±0.36 apical; at 60s 3.59±0.45 coronal and 2.85±.65 apical); circumferential, one-wall and horizontal defects ΔT (at 30s 0.91±0.16, 2.37±0.37, 0.64±0.32 coronal and 0.37±0.21, 1.17±0.24, 0.21±0.17 apical; at 60s 1.69±0.30, 3.06±0.25, 1.11±0.37 coronal and 0.73±0.20, 1.96±0.29, 0.51±0.20 apical), respectively. All test values were shown to be statistically significant (p<0.0001).
Conclusions: The morphology of the peri-implant defect may affect the resultant heat dissemination of Er,Cr:YSGG-laser irradiation on implants. Although none of the defects resulted in a temperature change greater than the 10^oC threshold, circumferential, two- and three-walled defects may have a greater risk for overheating and therefore irradiation should be kept within 30 second period.