Hard and soft tissue changes around implants activated using plasma of argon: A histomorphometric study in dog

ObjectiveTo histologically assess the hard and soft tissue changes after insertion of cleaned and activated titanium implants using plasma of argon. Materials and methodsEight dogs were included in this study. The mandibular premolars and first molars were extracted. For each hemi-mandible, four implants, 7mm long and 3.3mm of diameter, with a ZirTi surface were used. The surface of two implants was randomly treated with argon plasma (test), while the other two implants were left untreated (control). After 1month, the same procedure was performed in the contralateral hemi-mandible. The amount of old bone, new bone, overall value of old bone plus new bone, and soft tissue was histologically evaluated. ResultsAfter 1month of healing, high percentages of new bone in close contact with the implant surface were found at both the treated (60.1%15.6%; 95% CI 56.5%-78.0%) and untreated (57.2%+/- 13.1%; 95% CI 49.3%-67.5%) implants. Low percentages of old bone were found at this stage of healing, at both the treated (4.4%+/- 3.0%; 95% CI 1.2%-5.4%) and untreated (3.4%+/- 3.1%; 95% CI 0.6%-4.9%) implants. Not statistically significant differences were found between groups (p>.05). After 2months of healing, treated implants presented a significantly higher (p=.012) new bone formation (72.5%+/- 12.4%; 95% CI 69.6%-86.8%) compared to untreated sites (64.7%+/- 17.3%; 95% CI 59.4%-83.3%). Controversially, no difference (p=.270) in terms of old bone was present between treated (3.1%+/- 1.7%, 95% CI 1.8%-4.2%) and untreated implants (3.8%+/- 1.9%, 95% CI 3.2%-5.8%). Significant differences (p=.018) in terms of total mineralized bone were found between treated (75.6%+/- 13.0%, 95% CI 73.3%-91.3%) and untreated implants (68.4%+/- 16.8%; 95% CI 64.2%-87.6%). ConclusionsImplants treated using plasma of argon was demonstrated to reach a higher bone-to-implant contact when compared to untreated implants.