Bone healing at non-submerged implants installed with different insertion torques: a split-mouth histomorphometric randomized controlled trial

Validation of an implant stability measurement device using the percussion response: a clinical research study

Background

Several devices have been developed to measure implant-bone stability as an indicator of successful implant treatment; these include Osstell®, which measures the implant stability quotient (ISQ), and the more recent AnyCheck®, which relies on percussion for the implant stability test (IST). These devices make it possible to measure implant stability. However, no studies have compared the performance of AnyCheck® and Osstell® (i.e., IST and ISQ values) in clinical practice. Therefore, this study aimed to determine the correlation between primary and secondary implant stability using the Osstell® and AnyCheck® devices.

Methods

Ten patients (7 women; age [mean ± standard deviation]: 49.1 ± 13.3 years) with partially edentulous jaws who received a total of 15 implants were included. IST (AnyCheck®) and ISQ (Osstell®) values were measured immediately after implantation and at 1, 2, 3, 4, and 6 weeks post-implantation. Each measurement was performed three times, and the average value was used as the result. The correlation between measurements obtained using the two devices was determined using Spearman's rank correlation coefficient.

Results

The IST values ranged from 79.1 ± 2.87 to 82.4 ± 2.65. The ISQ values ranged from 76.0 ± 2.8 to 80.2 ± 2.35. Spearman's rank correlation coefficient was r = 0.64 immediately after implantation, r = 0.29 at 1 week, r = 0.68 at 2 weeks, r = 0.53 at 3 weeks, r = 0.68 at 4 weeks, and r = 0.56 at 6 weeks. A positive correlation was found in all cases, except at week 1 when the correlation was weak; the IST and ISQ values decreased the most during the first postoperative week and increased during the second week. The IST values were also slightly higher at all measurement points.

Conclusion

The ability to assess implant stability without removing the abutment during healing is essential for determining the timing of loading without the risk of bone resorption. The results of this study suggest that AnyCheck® is useful for determining primary and secondary implant stability.

The minipig intraoral dental implant model: A systematic review and meta-analysis

OBJECTIVES

The objective of this report was to provide a review of the minipig intraoral dental implant model including a meta-analysis to estimate osseointegration and crestal bone remodeling.

METHODS

A systematic review including PubMed and EMBASE databases through June 2021 was conducted. Two independent examiners screened titles/abstracts and selected full-text articles. Studies evaluating titanium dental implant osseointegration in native alveolar bone were included. A quality assessment of reporting was performed. Random-effects meta-analyses and meta-regressions were produced for bone-implant contact (BIC), first BIC, and crestal bone level.

RESULTS

125 out of 249 full-text articles were reviewed, 55 original studies were included. Quality of reporting was generally low, omissions included animal characteristics, examiner masking/calibration, and sample size calculation. The typical minipig model protocol included surgical extraction of the mandibular premolars and first molar, 12±4 wks post-extraction healing, placement of three narrow regular length dental implants per jaw quadrant, submerged implant healing and 8 wks of osseointegration. Approximately 90% of studies reported undecalcified incandescent light microscopy histometrics. Overall, mean BIC was 59.88% (95%CI: 57.43-62.33). BIC increased significantly over time (p<0.001): 40.93 (95%CI: 34.95-46.90) at 2 wks, 58.37% (95%CI: 54.38-62.36) at 4 wks, and 66.33% (95%CI: 63.45-69.21) beyond 4 wks. Variability among studies was mainly explained by differences in observation interval post-extraction and post-implant placement, and implant surface. Heterogeneity was high for all studies (I2 > 90%, p<0.001).

CONCLUSIONS

The minipig intraoral dental implant model appears to effectively demonstrate osseointegration and alveolar bone remodeling similar to that observed in humans and canine models.

Comparison between Early Loaded Single Implants with Internal Conical Connection or Implants with Transmucosal Neck Design: A Non-Randomized Controlled Trial with 1-Year Clinical, Aesthetics, and Radiographic Evaluation

To evaluate the implant and prosthetic of two implants with different surfaces and neck design. Enrolled patients received bone level, 12° conical connection implants (Nobel Parallel, Nobel Biocare; NOBEL group) with anodized surface (TiUnite) and roughness of 1.35 μm, or transmucosal implant system (Prama, Sweden and Martina; PRAMA group) with convergent collar, ZIrTi surface, and roughness 1.4–1.7 μm. Both implants were made of pure grade IV titanium, with similar diameter and length, chosen according to the dentistry department availability and patient’s request. After early prosthesis delivery, patients were filled for at least one year. Outcome measures were: implant and prosthetic survival and success rates, physiological marginal bone remodeling, periodontal parameters and pink esthetic score (PES). Results: Fifteen patients were allocated and treated in each group. At the one-year follow-up, three patients dropped out, one in the NOBEL group and two in the PRAMA group. During the entire time of investigation, all implants survived and the prostheses were successful. No statistically significant differences were found in term of marginal bone loss, periodontal parameters, and aesthetics (p > 0.05). Conclusion: With the limitations of the present study, both implant systems showed successful clinical results. Finally, many other clinical and surgical variables may influenced marginal bone levels, implant survival, and periodontal parameters. More homogenous clinical trials with larger samples are needed to confirm these preliminary conclusions.

The influence of insertion torque values on the failure and complication rates of dental implants: A systematic review and meta-analysis

BACKGROUND

The influence of using different insertion torque values on clinical and radiographic outcomes of implant therapy is unclear in the current literature. The aim of this systematic review and meta-analysis was to evaluate the implant outcomes and complications rates using high insertion torque values compared with those using regular insertion torque value levels.

METHODS

Randomized controlled trials (RCTs), nonrandomized controlled clinical trials (NRCCTs), prospective and retrospective cohorts were searched for in electronic databases and complemented by hand searching relevant dental journals. The risk of bias was assessed using the Cochrane Collaboration's Risk of Bias tool for randomized and nonrandomized studies. Data were analyzed using a statistical software.

RESULTS

A total of 718 studies were identified, of which, nine studies were included with 1229 dental implants in 684 participants. The meta-analysis of RCTs showed that the overall implant failure rate was not notably in favor of any insertion torque value and the difference between the two groups was not statistically significant (risk ratio 0.85; 95% confidence interval 0.07-10.52; P = 0.90). None of the RCTs was registered. The secondary analyses of non-RCTs did not either show any statistically significant difference. Overall meta-analysis did not show any significant differences in peri-implant marginal bone loss or biological/technical complications between high (≥50 Ncm) and regular insertion torque (<50 Ncm).

CONCLUSIONS

There is insufficient evidence to support the use of high or regular insertion torque even with immediate implant restoration/loading. The short-term implant failure rates, changes in marginal bone level and complication rates were comparable when high or regular insertion torques were used for implant placement. The wide confidence interval indicated that results cannot be interpreted with clinically meaningful benefit for using either high or regular insertion torque.

Survival rate and potential risk indicators of implant loss in non-smokers and systemically healthy periodontitis patients: An up to 9-year retrospective study

BACKGROUND

An increasing number of patients with chronic periodontitis (CP) have received implant restoration. However, very few studies have evaluated the probable risk indicators of implant loss in patients with CP.

OBJECTIVE

The aim of this study is to evaluate implant long-term survival rates in patients with CP. The results are analyzed to discern potential risk indicators of implant loss.

METHODS

A total of 1549 implants were inserted in 827 non-smokers and systemically healthy CP patients between March 2011 and March 2019. Clinical variables (age; sex; implant location; implant diameter; implant length; implant type; bone quality; bone graft, periodontal disease status, and insertion torque) were recorded. Kaplan-Meier survival curves illustrated the cumulative survival rate. The relationship between variables and implant loss was discerned by univariate analysis. Further multivariate Cox proportional hazard regression analysis was carried out for the variables with P < 0.2.

RESULTS

The cumulative survival rates were 98.8% after 3 months, 97.9% after 6 months, 97.7% after 1 year, and 97.4% after 2 to 9 years. After adjusting possible confounders, the multivariable Cox regression model revealed statistically significant influences of implant location, history of bone graft, and insertion torque on implant loss. Implants with history of bone graft were more likely to loss. Implants inserted in the anterior area had a higher implant loss risk; insertion torque of <15 Newton-centimeter (Ncm) showed a relatively high risk of being lost.

CONCLUSIONS

The study represented public hospital insight into long-term implant results of patients with CP. Under the premise of strict periodontal control, patients with the history of CP exhibited relatively high implant survival rate. Anterior implant location, history of bone graft, and insertion torque <15 Ncm are associated with a lower implant survival rate and could be considered at a higher risk of implant failure in patients with CP.

Healing at implants installed from ~ 70- to < 10-Ncm insertion torques: an experimental study in dogs

OBJECTIVE

To evaluate histologically the early healing at implants installed with different insertion torques MATERIAL AND METHODS: Three months after the extraction of the mandibular premolars and of the first molars, two implants were installed monolaterally in the premolar and two in the molar regions of the edentulous alveolar ridge of twelve dogs. The recipient sites were prepared using drills of different diameter to obtain insertion torque of different values, i.e., 30 Ncm (control) or ~ 70 Ncm (test) in the premolar region, and < 10 Ncm (test) or ~ 50 Ncm (control) in the molar region. Six animals were euthanized after 4 weeks and six after 8 weeks of healing. Histological analyses were performed, and the Wilcoxon test was applied for statistical analyses.

RESULTS

After 4 weeks of healing, in the premolar region, the new bone in contact with the implant surface was 65.0 ± 4.6% and 53.9 ± 13.5% at the ~ 30-Ncm and ~ 70-Ncm sites, respectively (p = 0.075). In the premolar region, new bone proportions were 51.4 ± 17.0% and 67.3 ± 7.0% at the < 10-Ncm and ~ 50-Ncm sites, respectively (p = 0.046). After 8 weeks of healing, in the premolar region, new bone reached fractions of 77.7 ± 16.2% at the ~ 30-Ncm sites, and 68.3 ± 12.1% at the ~ 70-Ncm sites (p = 0.028). In the molar region, new bone presented proportions of 70.2 ± 6.4% at the < 10-Ncm sites and 76.2 ± 9.4% at the ~ 50-Ncm sites (p = 0.173).

CONCLUSIONS

The insertion torque influenced the osseointegration of implants. Higher values of bone-to-implant contact percentages were registered for insertion torques of ~ 30 Ncm and ~ 50 Ncm. Implants inserted with torque < 10 Ncm became integrated with an optimal osseointegration.