Surface Characterization and In Vivo Evaluation of Dual Acid-Etched and Grit-Blasted/Acid-Etched Implants in Sheep

The Influence of Nanostructured Hydroxyapatite Surface in the Early Stages of Osseointegration: A Multiparameter Animal Study in Low-Density Bone

Background and Objective

The success rates of dental implants in low-density bone have been reported as a challenge, especially for early or immediate loading in the maxilla posterior area. Nanoscale architecture affects the roughness, surface area, surface energy of the implant and can enhance osseointegration. This study aimed to evaluate the implant-surface topography and biomechanical, histomorphometric, and histological bone responses to a new nanostructured hydroxyapatite surface placed in the iliac crest of sheep.

Methods

Ten female sheep (2–4 years) received 30 implants (n=10/group): HAnano^® coated (Epikut Plus^®, S.I.N. Implant System, Sao Paulo, SP, Brazil), SLActive (BLX^®, Straumann, Basel, Switzerland), and TiUnite (NobelActive^®, Nobel Biocare, Göteborg, Sweden) surfaces. Scanning electron microscopy with energy-dispersive spectroscopy evaluated the implant surface topography, the insertion torque value, and resonance frequency analysis evaluated the primary stability, bone-implant contact, and bone-area fraction occupancy were evaluated after 14 and 28 days after implant placement.

Results

The surface morphology was considerably comparable between the implant groups’; however, the TiUnite^® group presented a remarkable different surface. The SLActive^® and TiUnite^® groups presented an insertion torque average of 74 (±8.9) N/cm that was similar to that of HAnano^® 72 (±8.3) N/cm (p >0.05). The resonance frequency evaluated with Osstell^®/SmartPeg^® or Penguin^®/MulTipeg^® showed similar results when assessing implants from the same group. BIC and BAFO significantly increased (p<0.05) throughout the experimental periods to all groups, but BIC and BAFO values were similar among the implants at the same time point. After 4 weeks, bone-implant contact was higher than 80% of the total length analyzed. New bone occupies around 60% of analyzed area around the implants.

Conclusion

HAnano^® coated surface promoted comparable osseointegration as SLActive and TiUnite in the sheep model. The three tested surfaces showed comparable osseointegration at the early stages of low-density bone repair in the sheep model.

In Vivo Evaluation of Dual Acid-Etched and Grit-Blasted/Acid-Etched Implants With Identical Macrogeometry in High-Density Bone

PURPOSE

Based on the current evidence, the effect of implant macrogeometry has a significant influence on osseointegration. Thus, this study evaluated histomorphometrically and histologically the bone response to acid-etched in comparison to grit-blasted/acid-etched (GB) and machined control (C) surfaced implants possessing identical macrogeometry placed in high-density bone.

MATERIALS AND METHODS

Implant surface topography of the 3 different surfaced implants has previously been characterized. The macrogeometry of the implants were conical, and healing chambers were created in the cortical regions. The 3 groups were placed in the external mandibular body of adult male sheep (n = 5). After 6 weeks in vivo, all samples were retrieved for histologic observation and histomorphometry (eg, bone-to-implant contact [BIC] and bone area fraction occupancy [BAFO]).

RESULTS

No statistical difference was observed for BIC and for BAFO, although there was a tendency that the mean values for BAFO was higher for the textured surface groups.

CONCLUSIONS

It is suggested that the effect of surface topography is minimal in high-density bone and osseointegration seemed to be macrogeometry dependent.

Early Bone Response to Dual Acid-Etched and Machined Dental Implants Placed in the Posterior Maxilla: A Histologic and Histomorphometric Human Study

PURPOSE

To compare the early bone response to implants with dual acid-etched (DAE) and machined (MA) surface, when placed in the posterior human maxilla.

MATERIALS AND METHODS

Fourteen patients received 2 implants in the posterior maxilla: 1 DAE and 1 MA. After 2 months, the implants were retrieved for histologic/histomorphometric evaluation. The bone-to-implant contact (BIC%), bone density in the threaded area (BDTA%), and the bone density (BD%) were calculated. The Wilcoxon matched-pairs signed rank test was used to evaluate differences (BIC%, BDTA%, and BD%) between the surfaces.

RESULTS

In the MA implants, a mean (±SD) BIC%, BDTA%, and BD% of 21.76 (±12.79), 28.58 (±16.91), and 21.54 (±11.67), respectively, was reported. In the DAE implants, a mean (±SD) BIC%, BDTA%, and BD% of 37.49 (±29.51), 30.59 (±21.78), and 31.60 (±18.06), respectively, was reported. Although the mean BIC% of DAE implants value was almost double than that of MA implants, no significant differences were found between the 2 groups with regard to BIC% (P = 0.198) and with regard to BDTA% (P = 0.778) and BD% (P = 0.124).

CONCLUSIONS

The DAE surface increased the periimplant endosseous healing properties in the native bone of the posterior maxilla.