Comparative osseointegration of hydrophobic tissue-level tapered implants-A preclinical in vivo study.

PURPOSE: To histometrically compare the osseointegration and crestal bone healing of a novel tapered, self-cutting tissue-level test implant with a standard tissue-level control implant in a submerged healing regimen. MATERIALS AND METHODS: In a mandibular minipig model, implants were inserted and evaluated histometrically after a healing period of 3, 6, and 12 weeks. The primary outcome was the evaluation of bone-to-implant contact (BIC) and secondary outcomes were primary stability as per insertion torque and first BIC (fBIC). Outcomes for the test and control implants were compared using Wilcoxon signed-rank tests and mixed linear regression models. RESULTS: Insertion torque values were significantly higher for the test (50.0 ± 26.4 Ncm) compared to the control implants (35.2 ± 19.7 Ncm, p = .0071). BIC values of test implants were non-inferior to those of control implants over the investigated study period. After 12 weeks, the corresponding values measured were 81.62 ± 11.12% and 90.41 ± 4.81% (p = .1763) for test and control implants, respectively. Similarly, no statistical difference was found for fBIC values, except for the 12 weeks outcome that showed statistically lower values for the test (-675.58 ± 590.88 µm) compared to control implants (-182.75 ± 197.40 µm, p = .0068). CONCLUSIONS: Novel self-cutting tissue-level implants demonstrated noninferior osseointegration and crestal bone height maintenance to the tissue-level implants. Histometric outcomes between both implants demonstrated test implants were statistically noninferior to control implants, despite substantial differences in the bone engagement mechanism and resulting differences in insertion torque and qualitative bone healing patterns.

Histological evaluation of osseointegration between conventional and novel bone-level tapered implants in healed bone-A preclinical study.

AIMS: To histologically compare osseointegration and crestal bone healing between newly introduced tapered, self-cutting bone-level test implants and tapered bone-level control implants in sites with fully healed sites. METHODS: Sixty-six implants (33 test, 33 control) were placed 1 mm subcrestally in a minipig model and underwent qualitative histologic and quantitative histometric analyses after 3, 6 and 12 weeks of submerged healing. The primary and secondary outcomes were the bone-to-implant contact (BIC) and first bone-to-implant contact (fBIC). Outcomes between the test and control implants were statistically compared. RESULTS: The BIC values of the test implants were comparable and non-inferior over the time points studied, except for the 12 weeks time point which showed statistically significantly higher BIC values of the test (88.07 ± 5.35%) compared to the control implants (80.88 ± 7.51%) (p = .010). Similarly comparable and non-inferior were the fBIC values, except for the 6-week outcome, which showed statistically higher values for the test (-546.5 ± 450.80 µm) compared to the control implants (-75.7 ± 100.59 µm). fBIC results for the test implants were qualitatively more stable and consistent between test time points. CONCLUSION: Novel self-cutting bone-level test implants demonstrated superior osseointegration and similar bone levels compared to conventional bone-level implants after a healing period of 12 weeks in healed ridges.

Do magnification loupes affect the precision of cavity preparations made by undergraduates? A randomized crossover study.

BACKGROUND: Evidence on the effect of magnification devices on procedure quality in restorative dentistry is scant. This study therefore aimed to assess, under simulated clinical conditions, if magnification loupes affect the quality of preparations carried out by undergraduate dental students. METHODS: 59 undergraduate dental students underwent two visual acuity tests, based on which they were divided into a "low visual acuity group" (visus < 1) and a "good visual acuity group" (visus ≥ 1). In a randomized crossover experiment, participants performed a two-dimensional S and a three-dimensional O figure preparation with a dental handpiece on standardized acrylic blocs designed for preclinical restorative training. Each participant carried out the preparation tasks twice, once with magnification loupes (2.5×) and once without. Two blinded investigators independently evaluated parameters of preparation precision. Data were analyzed using Spearman rank correlation coefficients, intra-class correlation coefficients, and Wilcoxon rank-sum tests (α = 0.05). RESULTS: Participants from the "low visual acuity group" did not show a statistically significant improvement in accuracy when they used magnification loupes for the S figure preparation (p ≥ 0.0625). Participants from the "high visual acuity group" obtained a higher level of accuracy (p ≤ 0.0012) when they used magnification loupes for the S figure preparation. The use of magnification loupes had no statistically significant effect on the accuracy parameters of the O figure cavity preparations (p ≥ 0.1865). Participants with high visual acuity achieved only a marginally better accuracy than participants with a visus < 1. CONCLUSIONS: This study suggests that loupes with 2.5× magnification increase the accuracy of two-dimensional preparations while they have no significant effect, favorable or otherwise, on the accuracy of complex, three-dimensional cavity preparations of untrained dental students.