Histomorphometric evaluation of a dual acid-etched vs. a chemically modified hydrophilic dual acid-etched implant surface. An experimental study in dogs

Osseodensification enables bone healing chambers with improved low-density bone site primary stability: an in vivo study

Primary implant stability is a prerequisite for successful implant osseointegration. The osseodensification technique (OD) is a non-subtractive drilling technique that preserves the bone tissue, increases osteotomy wall density, and improves the primary stability. This study aimed to investigate the hypothesis that OD, through a wider osteotomy, produces healing chambers (HCs) at the implant-bone interface without impacting low-density bone primary stability. Twenty implants (3.5 × 10 mm) with a nanohydroxyapatite (nHA) surface were inserted in the ilium of ten sheep. Implant beds were prepared as follows: (i) 2.7-mm-wide using subtractive conventional drilling (SCD) technique (n = 10); (ii) 3.8-mm-wide using an OD bur system (n = 10). The sheep were randomized to two groups, with samples collected at either 14-(n = 5) or 28-days (n = 5) post-surgery and processed for histological and histomorphometric evaluation of bone-implant contact (BIC) and bone area fraction occupancy (BAFO). No significant group differences were found with respect to final insertion torque and implant stability quotient (p > 0.050). BIC values were higher for SCD after 14 and 28 days (p < 0.050); however, BAFO values were similar (p > 0.050). It was possible to conclude that the OD technique allowed a wider implant bed preparation without prejudice on primary stability and bone remodeling.

Implant stability and survival rates of a hydrophilic versus a conventional sandblasted, acid-etched implant surface: Systematic review and meta-analysis

BACKGROUND

Modifying the implant surface via enhancing the wettability (hydrophilicity) improves osseointegration, reducing the healing period. In this study, the authors aimed to evaluate the stability and survival rates of implants with a hydrophilic surface compared with those with a sandblasted, acid-etched surface.

TYPES OF STUDIES REVIEWED

The included studies (randomized controlled trials) were identified through searches of PubMed, ScienceDirect, and Cochrane Library databases without date of publication restrictions. Quality assessment was performed using the Cochrane Collaboration tool. For primary outcome, confidence intervals were set at 95%; weighted means across the studies were calculated using a fixed-effects model or risk ratios and their 95% confidence intervals for secondary outcome.

RESULTS

The authors included 5 randomized controlled trials (246 dental implants) in the systematic review, which compared a hydrophilic with conventional sandblasted, acid-etched implant surface. The implant stability (primary outcome) was measured at baseline and 3, 6, and 8 weeks, and implant survival rates were measured as a secondary outcome. Overall, compared with the control groups, no clinically significant differences in implant stability or survival rates were identified for the hydrophilic surface groups.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

The results did not show any clinically significant effect of a hydrophilic surface on improving implant stability or survival rates. However, these findings must be analyzed carefully owing to the limitations of this review, such as the small samples size and some differences among the included studies.

Effect of titanium surface functionalization with bioactive glass on osseointegration: An experimental study in dogs

PURPOSE

The purpose of this study was to evaluate the effect of surface functionalization with bioactive glass BSF18 on the osseointegration of sandblasted and dual acid-etched surface (AE) implants.

METHODS AND MATERIALS

Forty Morse taper implants with an AE surface as controls (C) or with an AE surface functionalized with BSF18 (BF) were placed in the mandibles of 10 beagles. Implants were analyzed after 2 and 4 weeks of healing. Implant stability quotient (ISQ) values were registered immediately after installation and prior to sacrifice. Samples were analyzed for bone-to-implant contact (BIC) and bone density (BD). The characterization of BF implants included surface roughness analysis with atomic force microscopy and contact angle (CA) analysis to evaluate wettability. Data were analyzed using two-way ANOVA followed by Tukey's test (p < 0.05).

RESULTS

Surface roughness was not affected by BF treatment. CA was lower in the BF group compared to the C group. No significant difference was observed in ISQ values between surfaces (p = 0,231), irrespective of time. Significantly higher ISQ values were observed for both implants after 4 weeks when compared with baseline (p = 0.04). Significantly higher BIC (p = 0.011) and BD (p = 0.025) values were observed for the BF compared to the C group at 2 weeks. Significantly higher BIC (p = 0.030) and BD (p = 0.015) values for the C group were observed at 4 weeks compared to 2 weeks. No significant difference was observed in the BF group between 2 and 4 weeks.

CONCLUSIONS

Implant functionalization with BSF18 improved the wettability of the implant surface; enhancing BIC and BD at 2 weeks.

Interfacial biomechanical properties of a dual acid-etched versus a chemically modified hydrophilic dual acid-etched implant surface: an experimental study in Beagles

BACKGROUND

The high survival clinical success rates of osseointegration are requisites for establishing a long-term biomechanical fixation and load-bearing potential of endosseous oral implants. The objective of this preclinical animal study was to evaluate the effect of surface microtopography and chemistry on the early stages of biomechanical rigidity with a sandblasted, dual acid-etched surface, with or without an additional chemical modification (SAE-HD and SAE, respectively), in the tibia of Beagle dogs.

METHODS

Two pairs of implants, with the same macrogeometry but different surface technology ((a) dual acid-etched surface treatment with hydrochloric and sulfuric acid followed by microwave treatment and insertion in isotonic saline solution to increase hydrophilicity (SAE-HD) (test, n = 12) and (b) dual acid-etched surface (SAE) (control, n = 12)), were installed bilaterally in the proximal tibia of six Beagle dogs. In order to determine the effect of surface modification on biomechanical fixation, a test protocol was established to assess the torque and a complete set of intrinsic properties. Maximum removal torque (in N cm) was the primary outcome measure, while connection stiffness (N cm/rad) and removal energy (× 10^-2J) were the secondary outcome measures and were assessed after 2 and 4 weeks in vivo. A general linear statistical model was used and performed for significant differences with the one-way ANOVA followed by Tukey post hoc test (P < 0.05).

RESULTS

The removal torque values did not reveal significant statistical differences between SAE-HD and SAE implants at any observation times (P = 0.06). Although a slight increase over time could be observed in both test and control groups. SAE-HD showed higher removal energy at 4 weeks (999.35 ± 924.94 × 10^- 2 J) compared to that at 2 weeks (421.94 ± 450.58 × 10^- 2 J), while SAE displayed lower values at the respective healing periods (P = 0.16). Regarding connection stiffness, there were no significant statistical differences neither within the groups nor over time. There was a strong, positive monotonic correlation between removal torque and removal energy (=0.722, n = 19, P < 0.001).

CONCLUSIONS

In this study, no significant differences were observed between the specific hydrophilic (SAE-HD) and hydrophobic (SAE) surfaces evaluated, in terms of biomechanical properties during the early osseointegration period.