Stability of implants placed in fresh sockets versus healed alveolar sites: Early findings

A graftless maxillary sinus lifting approach with simultaneous dental implant placement: a prospective clinical study

PURPOSE

This study aimed to introduce a graftless sinus lifting approach with simultaneous dental implant placement in the alveolus of the posterior maxilla and compare this approach's outcomes in freshly extracted sockets versus healed sockets.

MATERIALS AND METHODS

A prospective study was conducted on 60 patients aged between 27 and 59 years old, requiring dental implants in the posterior maxilla, and diagnosed with reduced vertical bone height (30 with freshly extracted sockets (group A) and the remaining 30 with healed sockets (group B). Before the sinus lifting approach, a cone beam computed tomography (CBCT) was taken, followed by another CBCT at least one-year post-sinus lifting (range: 12-36 months). Biological and mechanical complications were assessed, and the primary implant stability was measured using the Implant Stability Quotient (ISQ). Parametric data were analyzed using an independent t-test for intergroup comparisons, with significance set at P < 0.05.

RESULTS

No significant differences were found among groups concerning gender, placement side, and follow-up. All dental implants demonstrated high survival rates with no observed biological or mechanical complications. Moreover, the primary implant stability was satisfactory, and there was no statistically significant difference (P = 0.38). In terms of new intrasinus bone formation, both groups exhibited satisfactory and successful outcomes, with increased new bone formation in group A. However, there was no statistically significant difference (P = 0.26). Regarding the vertical sinus floor elevation without new bone formation, group B showed (0.11 ± 0.64) mm of intrasinus implant height without bone formation, while group A showed an increment of bone formation above the intrasinus implant (0.22 ± 0.33) mm, with no statistically significant difference between both groups (P = 0.30).

CONCLUSION

Our approach proves to be predictable, low-cost, and efficient option for sinus lift procedures, demonstrating high survival rates with acceptable primary implant stability. Moreover, it yields satisfactory outcomes in terms of new intrasinus bone formation, both in freshly extracted and healed sockets. Consequently, our approach holds promise as a reliable procedure for sinus lifting with simultaneous dental implant placement.

Randomized Clinical Trial Comparing Insertion Torque and Implant Stability of Two Different Implant Macrogeometries in the Initial Periods of Osseointegration

Objectives: The present study compared two implants with different macrogeometries placed in healed alveolar sites, evaluating the insertion torque (ITV) and implant stability quotient (ISQ) values at three different periods. Methods: Seventy patients with a total of 100 dental implants were allocated into two groups (n = 50 per group): DuoCone implants (DC group) that included 28 implants in the maxilla and 22 in the mandible, and Maestro implants (MAE group) that included 26 in the maxilla and 24 in the mandible. The ITV was measured during the implant placement, and the ISQ values were measured immediately at implant placement (baseline) and after 30 and 45 days. Results: The mean and standard deviations of the ITV were statistically significant (p < 0.0001), 56.4 ± 6.41 Ncm for the DC group and 29.3 ± 9.65 Ncm for the MAE group. In the DC group, the ISQs ranged between 61.1 ± 3.78 and 69.8 ± 3.86, while the MAE group presented similar values compared with the other group, ranging between 61.9 ± 3.92 and 72.1 ± 2.37. Conclusions: The value of implant insertion torque did not influence the ISQ values measured immediately after implant placement. However, the ITV influenced the ISQ values measured in the two initial periods of osseointegration, with implants installed with lower torques presenting higher ISQ values.

Dental Implants Inserted in Fresh Extraction Sockets versus Healed Sites: A Systematic Review and Meta-Analysis

The present review aimed to evaluate the difference of dental implant failure rates and marginal bone loss (MBL) between implants inserted in fresh extraction sockets or healed sites. Electronic search was undertaken in three databases, plus manual search of journals, including studies randomized or not. Meta-analyses were performed besides meta-regressions, in order to verify how the odds ratio (OR) and MBL were associated with follow-up time. The review included 163 publications. Altogether, there were 17,278 and 38,738 implants placed in fresh extraction sockets and healed sites, respectively. Pairwise meta-analyses showed that implants in sockets had a higher failure risk in comparison to healed sites: OR 1.349, all studies included; OR 2.070, only prospective non-RCTs; OR 2.487, only RCTs (all p < 0.001). The difference in implant failure between the groups was statistically significant in the maxilla (OR 1.616, p = 0.029), but not in the mandible (OR 2.192, p = 0.075). The MBL mean difference (MD) between the groups was −0.053 mm (p = 0.089). There was an estimated decrease of 0.003 in OR (p = 0.284) and an increase of 0.006 mm (p = 0.036) in the MBL MD between groups for every additional month of follow-up. In conclusion, implants placed in fresh extraction sockets present higher risk of failure than implants placed in healed sites.

Correlation between Primary, Secondary Stability, Bone Density, Percentage of Vital Bone Formation and Implant Size

BACKGROUND

This study aims to evaluate whether there is a correlation between implant stability, bone density, vital bone formation and implant diameter and length.

METHODS

Ninety patients were enrolled in this study. They underwent a socket preservation procedure with allograft or PRF and after 4 months, a total of 90 implants were placed. CBCT scans were assigned prior to implant placement in order to assess the bone density. During the surgical re-entry, a bone biopsy was harvested with a trephine drill. Immediately after implant insertion, the primary stability was measured. The secondary stability was measured 4 months after implant placement.

RESULTS

Primary stability showed a significant positive linear correlation with bone density (r = 0.471, p < 0.001) as well as with percentage of new bone formation (r = 0.567, p < 0.001). An average significant association of secondary stability with bone density (rs = 0.498, p < 0.001) and percentage of newly formed bone (r = 0.477, p < 0.001) was revealed. The mean values of primary stability in all three implant sizes, regarding the diameter of the implants, were similar (narrow 67.75; standard 66.78; wide 71.21) with no significant difference (p = 0.262). The same tendency was observed for secondary stability (narrow 73.83; standard 75.25; wide 74.93), with no significant difference (p = 0.277).

CONCLUSIONS

The study revealed a high correlation between primary and secondary implant stability, and bone density, as well as with the percentage of vital bone formation. Implant length and diameter revealed no linear correlation with the implant stability.

The clinical significance of implant stability quotient (ISQ) measurements: A literature review

Implant stability quotients (ISQ values) are obtained in dental clinical practice on a non-invasive basis by resonance frequency measurement rapidly after surgical placement of implants. The ISQ-values are used as indicator for mechanical implant stability, and are believed to have predictive power for clinical outcome. It is the aim of this review to provide a synopsis of all factors described in the literature that influence ISQ measurements by performing an exhaustive literature review; moreover, this review aims at elucidating the key factors relevant for a rapid clinical predictive assessment. We searched systematically and exhaustively all major databases for publications relating to ISQ measurement methodology and for ISQ-influencing factor analyses. The reports identified were ordered in experimental (preclinical) studies and in clinical publications. We were able to identify 13 basic factors influencing ISQ-measurements. Among these, local bone quality, playing a key role in such measurements, was subdivided in four specific subfactors; thus a total of 17 individual factors was identified and reported to influence ISQ-measurements. A comprehensive list of these factors is provided in Table-form. A critical analysis points out that only 6 of these factors are of a sound predictive power useful for a rapid clinical assessment; and only two of these factors appear to have a well-documented scientific basis.

Influence of Mucosal Thickness, Implant Dimensions and Stability in Cone Morse Implant Installed at Subcrestal Bone Level on the Peri-Implant Bone: A Prospective Clinical and Radiographic Study

The objective of this observational clinical study was to analyze the behavior of peri-implant tissues around cone Morse dental implants installed in the subcrestal bone position considering different clinical variables: Mucosal thickness, implant diameter, and implant length. Thirty patients were selected and included in the present study. Initially the thickness of the mucosa was measured by periapical radiographic and clinically (after the mucosal displaced). According to the planning for each treatment, implants with different dimensions (in length and diameter) were selected and used. Periapical radiographs were obtained at different times: Immediate postoperative (time t1) and 90 days after implantation (time t2). The initial stability of the implants (ISQ) was measured immediately of the implant insertion and 90 days after. The means and standard deviations of the ISQ values were in time t1 was 63.2 ± 6.99 (95% confidence interval (CI): 41 to 83) and in time t2 was 69.7 ± 7.09 (95% CI: 61 to 87). Overall mean of mesial and distal bone loss 90 days after the implantations were 1.11 ± 1.16 mm and 1.11 ± 1.15 mm, respectively. When the variables were considered, in all situations proposed, the bone loss showed differences statistically significant. In conclusion, the implant diameter and mucosal thickness variables showed an important effect on bone loss values. However, the implant length did not show an effect on the peri-implant behavior.

Evaluation of dimensional behavior of peri-implant tissues in implants immediately exposed or submerged in fresh extraction and healed sites: a histological study in dogs

Background

The aim of this study was to compare histologically the dimensional behavior of peri-implant tissues during osseointegration of immediately exposed or submerged implant placement in fresh extraction and healed sites.

Methods

Four fresh extraction and four delayed implant sites were placed in each hemimandible of five dogs at the bone crest level. In 2 implants of each side were installed a healing abutment (exposed) and two cover screw (submerged) and formed four groups: implant installed in fresh extraction submerged (group 1), implants in fresh extraction immediately exposed (group 2), implants installed in healed site submerged (group 3), and implants in healed site immediately exposed (group 4). After 12 weeks of healing period, histomorphometric analyses of the specimens were carried out to measure the crestal bone level values and the tissue thickness in the implant shoulder portion.

Results

The measure of crestal bone level showed some higher values for implants installed in fresh extraction sites in the buccal aspect: 1.88 ± 0.42 mm for group 1 and 2.33 ± 0.33 mm for group 2, with statistical significance among all four groups tested (P < 0.001). For peri-implant tissue thickness, a significative higher statistical difference (P < 0.001) for implants installed in healed sites (groups 3 and 4) was found.

Conclusions

Within the limitations of the present animal study, our findings suggest that the implants placed in fresh extraction or healed site and with regards to the moment of exposition (immediately or no) are important factors to the amount of peri-implant tissues after remodeling over a period of 12 weeks. The null hypothesis was rejected.

Immediate Loading of Tapered Implants Placed in Postextraction Sockets and Healed Sites

OBJECTIVE

The aim of the present study was to compare the survival, stability, and complications of immediately loaded implants placed in postextraction sockets and healed sites.

METHODS

Over a 2-year period, all patients presenting with partial or complete edentulism of the maxilla and/or mandible (healed site group, at least 4 months of healing after tooth extraction) or in need of replacement of nonrecoverable failing teeth (postextraction group) were considered for inclusion in this study. Tapered implants featuring a nanostructured calcium-incorporated surface were placed and loaded immediately. The prosthetic restorations comprised single crowns, fixed partial dentures, and fixed full arches. Primary outcomes were implant survival, stability, and complications. Implant stability was assessed at placement and at each follow-up evaluation (1 week, 3 months, and 1 year after placement): implants with an insertion torque (IT) <45 N·cm and/or with an implant stability quotient (ISQ) <70 were considered failed for immediate loading. A statistical analysis was performed.

RESULTS

Thirty implants were placed in postextraction sockets of 17 patients, and 32 implants were placed in healed sites of 22 patients. There were no statistically significant differences in ISQ values between the 2 groups, at each assessment. In total, 60 implants (96.8%) had an IT ≥45 and an ISQ ≥70 at placement and at each follow-up control: all these implants were successfully loaded. Only 2 implants (1 in a postextraction socket and 1 in a healed site, 3.2%) could not achieve an IT ≥45 N·cm and/or an ISQ ≥70 at placement or over time: accordingly, these were considered failed for stability, as they could not be subjected to immediate loading. One of these 2 implants, in a healed site of a posterior maxilla, had to be removed, yielding an overall 1-year implant survival rate of 98.4%. No complications were reported. No significant differences were reported between the 2 groups with respect to implant failures and complications.

CONCLUSION

Immediately loaded implants placed in postextraction sockets and healed sites had similar high survival and stability, with no reported complications. Further long-term studies on larger samples of patients are needed to confirm these results.

Mathematical evaluation of the influence of multiple factors on implant stability quotient values in clinical practice: a retrospective study

Objectives

The objective of this study is to mathematically evaluate the influence of multiple factors on implant stability quotient values in clinical practice.

Patients and methods

Resonance frequency analysis was performed at T1 (measured immediately at the time of implant placement) and at T2 (measured before dental restoration) in 177 patients (329 implants). Using a multivariate linear regression model, we analyzed the influence of the following eleven candidate factors: sex, age, maxillary/mandibular location, bone type, immediate/delayed implantation, bone grafting (presence or absence), insertion torque, I-/II-stage healing pattern, implant diameter, implant length, and T1–T2 time interval.

Results

The following factors were identified to significantly influence the implant stability quotient (ISQ) values at T1: insertion torque, bone grafting, I-/II-stage healing pattern, immediate/delayed implantation, maxillary/mandibular location, implant diameter, and sex. In contrast, the ISQ values at T2 were significantly influenced only by three factors: implant diameter, T1–T2 time interval, and insertion torque.

Conclusion

Among the eleven candidate factors, seven key factors were found to influence the T1-ISQ values, while only three key factors influenced the T2-ISQ values. Both T1 and T2-ISQ values were found to be influenced by implant diameter and insertion torque. T1 was influenced specifically by the sex of the patient, the location (maxillary or mandibular), the implantation mode (immediate/delayed implantation), the healing stage, and the absence or presence of bone graft materials.

Retracted: A new cervical implant design compared with standard design in order to increase peri-implant hard and soft tissue behavior: histomorphometric and histological study in dogs

OBJECTIVE

The aim of this study was to evaluate a new design of the cervical portion of dental implant with the objective to increase the volume of peri-implant tissues in the crestal area.

MATERIALS AND METHODS

Forty-eight tapered dental titanium implants with internal conical connection were implanted in healed alveolar sites of six dogs. Twenty-four conventional implants design (C1 implant) formed the control group, and 24 new implant design (V3 implant) formed the test group. The groups were randomized. Histological, histomorphometric, and implant stability quotient were performed. After 12 weeks of healing period, histomorphometric analyses of the specimens were carried out to measure the crestal bone level values and the tissue thickness in the cervical implant portion. The data were compared using statistical tests (α = 5%).

RESULTS

The mean of the measurements in the buccal and lingual aspects measured of crestal bone level was 0.31 ± 0.24 mm and 0.30 ± 0.19 mm in the control group, respectively, and 0.71 ± 0.28 and 0.42 ± 0.30 mm in the test group, respectively, whereas the mean of the tissue thickness was 1.63 ± 0.33 mm and 2.04 ± 0.23 mm in the control group, respectively, and 2.11 ± 0.35 mm and 2.51 ± 0.41 mm in the test group.

CONCLUSIONS

Within the limitations of this study, our findings suggest that more thickness of peri-implant hard and soft tissues may be expected in this new implant design. However, the control group with traditional implant design was found to have more height values of the crestal bone compared with new V3 implants.

Stability and Crestal Bone Behavior Following Simultaneous Placement of Multiple Dental Implants (Two or More) with the Bone Splitting Technique: A Clinical and Radiographic Evaluation

PURPOSE

The present study aimed to measure the implant stability quotient (ISQ) values at three different time points after surgical procedures and crestal bone behavior in multiple implants (two or more) installed simultaneously with the bone splitting technique.

MATERIALS AND METHODS

For this study, 45 patients with different edentulous areas in the maxilla were selected, and a total of 114 dental implants were installed. Implant stability was measured by resonance frequency analysis immediately following implant placement to assess immediate stability (time 1) and stability at 90 days (time 2), and 150 days (time 3). Crestal bone height was measured in peri-apical radiographs at 90 and 150 days after implantation in relation to each implant shoulder, given that the implants were installed at the level of the crestal bone.

RESULTS

Six implants were not osseointegrated. Overall, the means and standard deviations of the ISQ values were 60.3 ± 4.94 (95% confidence interval [CI], 44-69) at baseline, 66.6 ± 5.28 (95% CI, 49-75) at 90 days, and 72.1 ± 4.28 (95% CI, 59-79) at 150 days (p < 0.0001). The mean marginal bone loss of the implants was 1.11 ± 0.61 mm on the mesial side and 1.17 ± 0.61 mm on the distal side at time 2, and 1.73 ± 0.68 mm on the mesial side and 1.79 ± 0.70 mm on the distal side at time 3. A strong positive correlation between implant stability and bone loss was detected (p < 0.0001).

CONCLUSIONS

Within the limits of this study, the bone splitting technique with simultaneous implant installation exhibited a good success rate with respect to the osseointegration index but requires attention with respect to crestal bone behavior.