Stability Evaluation of Implants Integrated in Grafted and Nongrafted Maxillary Bone: A Clinical Study from Implant Placement to Abutment Connection

Towards Optimum Mandibular Reconstruction for Dental Occlusal Rehabilitation: From Preoperative Virtual Surgery to Autogenous Particulate Cancellous Bone and Marrow Graft with Custom-Made Titanium Mesh-A Retrospective Study

The purpose of this retrospective study was to evaluate computer-assisted virtual surgery and the outcomes of mandibular reconstruction using an autogenous particulate cancellous bone and marrow (PCBM) graft combined with a custom-made titanium mesh (TiMesh) using a three-dimensional (3D) printing model. Eighteen consecutive patients were included, and preoperative virtual simulation surgery was performed using digital data. Segmental bone defects showed deviation of the mandible due to displacement of the condyle and segments, unnatural length of the mandibular body, or poorer intermaxillary relationship compared to the marginal bone defect caused by previous operations. These mandibular disharmonies could be simulated, and virtual surgery was performed on a computer with adjustment of displaced mandibular segments, length of the mandibular body, and dental arch with digital bone augmentation. TiMesh was manually pre-bent using a 3D printing model, and PCBM from the iliac crest was grafted with TiMesh. The short-term clinical results were good; reconstruction of the alveolar crest was prosthetically desirable; and minor complications were observed. In conclusion, virtual reconstruction is crucial for treating complex deviated mandibles. Accurate condylar and dental arch positions with an optimum mandibular length are important for prosthetically satisfactory mandibular reconstruction.

EFFECT OF AUTOGENOUS BONE GRAFT SITE ON DENTAL IMPLANT SURVIVAL AND DONOR SITE COMPLICATIONS: A SYSTEMATIC REVIEW AND META-ANALYSIS

OBJECTIVES

This systematic review and meta-analysis was undertaken to answer the following focus questions: Is the implant survival in augmented bone utilizing iliac crest bone grafts the same as while using intraoral autologous bone grafts? Is the incidence of postoperative donor site complications the same when using iliac crest bone grafts as opposed to intraoral grafts?

METHODS

Systematic searches of electronic databases (PubMed, Embase, CENTRAL) were performed to identify studies which reported on implant survival and postoperative complications for dental implants placed in grafted partially/completely edentulous human jaws. Studies were included if: they reported on 2-piece micro-rough surface root form dental implants placed in bone-augmented completely or partially edentulous human jaws, and the jaws must have been augmented with autologous bone graft materials. Time and nature of postoperative complications must have been reported. Two investigators performed data extraction and a Cohen's unweighted kappa was calculated for inter-investigator reliability. A meta-analysis was performed for the extracted data on implant survival rate in both iliac crest grafts and intra-oral grafts. A qualitative analysis was performed on the information extracted on graft donor site complications. Quality assessment of the included studies were done using the Cochrane collaboration tool and the Newcastle-Ottawa scales.

RESULTS

A total of 23 studies were included in the final analysis. The calculated kappa ranged between 0.77-0.89 for the literature search and identification process. Fourteen studies were included with data on implant survival including five randomized controlled clinical trials. The meta-analysis of included studies revealed that the implant survival rate of dental implants placed in jaws augmented with iliac crest grafts was lower than those placed in jaws augmented with intra-oral bone grafts at 6-months [ICG = 95.8% IOG = 98.4%; P < .001], 12-months [ICG = 97.0%, IOG = 98.4%; P < .001], 24-months [ICG = 85.9%, IOG = 98.2%; P < .001], 60-months [ICG = 90.0%, IOG = 91.5%; P < .001], and at 120-months [ICG = 88.8%, IOG = 95.2%; P < .001] follow-up periods. Iliac crest grafts were also frequently associated with donor site complications including pain / discomfort, gait disturbance, and sensory disturbance.

CONCLUSIONS

This systematic review and meta-analysis demonstrates that implant survival is consistently higher in bone harvested from intraoral sites compared to iliac crest grafts. Donor site complications seemed to be a frequent finding with iliac crest grafts and mental grafts.

FUNDING

None.

REGISTRATION

The review protocol was registered with PROSPERO: International prospective register of systematic reviews (CRD42021283738).

Use of transcortical miniscrews for alveolar ridge preservation following tooth extraction: A pilot study

OBJECTIVES

The purpose of this split-mouth pilot study was to investigate the effects of a transcortical miniscrew placed over the buccal plate of an extraction socket for alveolar ridge preservation in humans.

METHODS

One week after the extraction of bilateral maxillary premolars, cone-beam computed tomography (CBCT) and intraoral digital imaging were performed (T0). A transcortical miniscrew was placed over the buccal plate of the extraction socket on one side (experiment), and the extraction socket on the contralateral side was left untreated (control). Follow-up CBCT and intraoral digital imaging were performed at 8 months immediately after miniscrew removal (T8). Changes in the width of the alveolar bone and ridge were measure by superimposing T0 and T8 of CBCTs and intraoral digital scans.

RESULTS

Six participants completed the study protocol. Overall, the experimental side with the miniscrew demonstrated less bone loss and less alveolar ridge reduction than the control side. Bone loss on the experimental side (0.7 ± 0.2 mm) was significantly less than that on the control side (1.3 ± 0.7 mm) at the apical level of the socket on axial CBCT imaging (Wilcoxon signed rank test, p = .031). The experimental side (-18 ± 8%) exhibited less reduction in the alveolar ridge width than the control side (-21 ± 12%) at the crestal level on coronal superimposition of the intraoral digital scans.

CONCLUSIONS

Transcortical miniscrew placement over the buccal plate of the extraction socket resulted in less resorption of the alveolar ridge and bone 8 months after tooth extraction.

CLINICAL TRIAL REGISTRATION

NCT03205800: Temporary Anchorage Devices for Ridge Preservation (TAD).

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.

Eight to eleven-year follow-up of immediately loaded implants placed in edentulous maxillae with compromised bone volume and poor bone quality: A prospective cohort study

BACKGROUND

There is a lack of long-term evaluations of immediately loaded implants in patients with compromised maxillary bone.

PURPOSE

To evaluate long-term survival and success of immediately loaded implants in subjects with poor maxillary bone quality and volume.

MATERIAL AND METHODS

Follow-up was performed on subjects who received six implants loaded within 24 hours with screw-retained fixed prostheses. Twenty-five subjects with limited bone (Lekholm and Zarb, quantity 3 and 4, and quality C and D) were included in the study. Nineteen participated in the radiographic examination and of these 17 participated in the clinical examination at the last visit. Evaluations of marginal bone loss were performed at 1, 3, 5, and 8-11 years. The last clinical examination included removal of the prosthesis followed by registration of: plaque, pus, pocket depth, bleeding upon probing, mobility, and percussion testing.

RESULTS

The mean follow-up was 9 years and 2 months (101-131 months) after surgery and showed a cumulative implant survival rate of 81.9% and success rate of 74.7%. Mean marginal bone loss was 1.29 mm (SD 2.47 mm range 0-11 mm) with a mean pocket depth of 3.1 mm (SD 2.4 mm, range 1.5-13.5 mm). 42.5% of the implants showed plaque retention and 72.2% showed bleeding on probing.

CONCLUSION

This nonaugmenting immediate loaded implant protocol for maxillary edentulous patients is a satisfactory solution for selected patients.

Maxillary sinus floor elevation using hydroxyapatite nano particles vs tenting technique with simultaneous implant placement: A randomized clinical trial

PURPOSE

The present study was conducted to evaluate the amount of bone height gain, density values, and implant stability after maxillary sinus floor elevation using graftless tenting technique or the use of Hydroxyapatite Nanoparticles bone substitute for augmentation with simultaneous implant placement.

MATERIALS AND METHODS

A total of 20 sinuses with a residual alveolar bone height ranging from 4-6 mm were divided into two groups and underwent sinus augmentation using nano hydroxyapatite bone substitute material and the graftless tenting technique with simultaneous implant placement. Computed tomography CT scans and ISQ measurements were conducted to evaluate bone quality, quantity, and implant stability.

RESULTS

Radiographic analysis revealed that the mean bone height gain of the nano group was (7.0 ± 0.8 mm) compared to (5.0 ± 1.5 mm) in the tent group, which was statistically significant (P = .002) being higher in the nano group. The mean bone density value of the nano group was (548 ± 25 HU) compared to (420 ± 23 HU) in the tent group, which was statistically significant (P < .001) being higher in the nano group. The mean ISQ value after 6 months in the nano group was (78 ± 5) compared to (77 ± 5) in the tent group, which was statistically nonsignificant (P = .901).

CONCLUSION

Nano hydroxyapatite bone graft offered superior results in terms of the bone height gain and the relative bone density as compared to graftless tenting technique. However, both techniques showed accepted results regarding implant stability.

Survival of dental implants at sites after implant failure: A systematic review

STATEMENT OF PROBLEM

Despite an overall high survival rate for dental implants, the effectiveness of implant retreatment remains unclear.

PURPOSE

The purpose of this systematic review was to examine the survival rate of implants placed at sites which had an implant failure and to investigate factors that might affect outcomes after retreatment.

MATERIAL AND METHODS

A search of electronic databases limited to English language articles was conducted using the following MeSH terms: "dental implants," "dental implantation," or "dental restoration failure," combined with "retreatment," "replacement," or "reoperation." A hand search of selected journals was also performed. Of the retrieved 668 publications, 8 retrospective clinical studies met the inclusion criteria, providing the survival outcome for 673 implants in 557 patients after retreatment. Implant- and patient-related characteristics related to implant failures were assessed.

RESULTS

The weighted mean survival rate for implants after retreatment was 86.3%, with follow-up ranging from less than 1 year to over 5 years. The survival rates of smooth-surfaced and rough-surfaced implants were compared in 217 retreated implants, revealing a significantly higher survival rate for rough-surfaced implants than for smooth-surfaced implants (90% versus 68.7%). Insufficient data were available to evaluate the effect of patient- or treatment-related characteristics on the survival of implants after retreatment.

CONCLUSIONS

The survival rate of retreated implants is lower than that generally reported after initial implant placement. Higher survival rates were reported with rough-surfaced implants than with smooth-surfaced implants in retreatment. An overall implant survival rate of 86.3% after retreatment suggests that most initial implant failures are likely attributable to modifiable risk factors, such as implant architecture, anatomic site, infection, and occlusal overload.

Relationship between cortical bone thickness and implant stability at the time of surgery and secondary stability after osseointegration measured using resonance frequency analysis

Purpose

It has been suggested that resonance frequency analysis (RFA) can measure changes in the stability of dental implants during osseointegration. This retrospective study aimed to evaluate dental implant stability at the time of surgery (primary stability; PS) and secondary stability (SS) after ossseointegration using RFA, and to investigate the relationship between implant stability and cortical bone thickness.

Methods

In total, 113 patients who attended the Tohoku University Hospital Dental Implant Center were included in this study. A total of 229 implants were placed in either the mandibular region (n=118) or the maxilla region (n=111), with bone augmentation procedures used in some cases. RFA was performed in 3 directions, and the lowest value was recorded. The preoperative thickness of cortical bone at the site of implant insertion was measured digitally using computed tomography, excluding cases of bone grafts and immediate implant placements.

Results

The mean implant stability quotient (ISQ) was 69.34±9.43 for PS and 75.99±6.23 for SS. The mandibular group had significantly higher mean ISQ values than the maxillary group for both PS and SS (P<0.01). A significant difference was found in the mean ISQ values for PS between 1-stage and 2-stage surgery (P<0.5). The mean ISQ values in the non-augmentation group were higher than in the augmentation group for both PS and SS (P<0.01). A weak positive correlation was observed between cortical bone thickness and implant stability for both PS and SS in all cases (P<0.01).

Conclusions

Based on the present study, the ISQ may be affected by implant position site, the use of a bone graft, and cortical bone thickness before implant therapy.

Do short implants have similar survival rates compared to standard implants in posterior single crown?: A systematic review and meta-analysis

BACKGROUND

Short implants have been presented as an option for posterior rehabilitation in cases of poor bone height.

PURPOSE

To compare the survival rate of short implants and standard implants when used in posterior single crowns, in addition to reporting marginal bone loss, prosthetic failures, and surgical complications.

MATERIALS AND METHODS

Electronic search (PubMed, LILACS, Cochrane Library, Scopus, and Web of Science) and hand search were performed to identify all randomized controlled trials (RCTs) and controlled clinical trials (CCTs) that evaluated both short and standard implants in posterior single crowns.

RESULTS

Out of 345 articles identified by both electronic and hand search, four studies were selected (one CCT and three RCTs). The meta-analysis for the survival rate showed that there was no significant difference between the short implants and the standard ones (P = 1.00; RR:1.00; CI:0.97-1.03) performed with three RCTs for a one-year follow-up. The mean marginal bone loss ranged from 0.1 mm to 0.54 mm. Only one study reported the presence of prosthetic failures and surgical complications.

CONCLUSIONS

The survival rate of short implants was similar to the standard ones in posterior single crowns, for the one-year follow-up period. They also presented low surgical complications, prosthetic failures and marginal bone loss, being a predictable treatment for single rehabilitation in posterior tooth loss.

Endoscopically controlled flapless transcrestal sinus floor elevation with platelet-rich fibrin followed by simultaneous dental implant placement: A case report and literature review

RATIONALE

In this case study, a modified transcrestal approach was applied to the patient of extremely atrophic posterior maxilla. We analysis the Implant Stability Quotient values (ISQ) to monitor implant stability, and the cone-beam computer tomography (CBCT) to evaluate the bone regeneration.

PATIENT CONCERN

A 26-year-old female patient visited our hospital with no contraindications for dental implants and a loss of the maxillary right first molar.

DIAGNOSE

Examination by CBCT demonstrated the posterior maxilla was extremely atrophic, the residual bone height (RBH) of #16 was 3.5 mm.

INTERVENTION

Patient underwent a endoscopically controlled flapless sinus floor elevation. The maxillary sinus membrane was elevated by two-step, and an implant of 12 mm length was placed simultaneously.

OUTCOMES

Twelve weeks post-surgery, the implant-level impression was finished and a full-ceramic crown was placed thereafter.

LESSONS

The modified transcrestal approach can be applied to augment maxillary sinus with a residual bone height less than 4 mm.

Assessment of Dental Implant Stability in Areas Previously Submitted to Maxillary Sinus Elevation

This study aimed to compare the primary and secondary stability, measured by resonance frequency analysis (RFA), in implants of different lengths installed in areas submitted to maxillary sinus lift. Correlation between RFA and implant insertion torque was also assessed. Twenty implants of 9 and 11 mm were inserted in areas submitted to maxillary sinus lift. The insertion torque was measured by the Bien Air motor. Osstell, through RFA, determined the implant stability quotient (ISQ) 2 times: the day of implant installation (T1) and 90 days after implant installation (T2). No differences were observed in the ISQ between T1 and T2 when the 20 implants were grouped, nor when the 9 mm implants were evaluated separately. In contrast, when the 11 mm values were evaluated separately, the ISQ was significantly higher in T2 than in T1 ( P < .05). In T1, 9 mm implants had a higher ISQ than 11 mm ones ( P < .05), whereas in T2, the implants of 11 mm showed a higher ISQ than did the 9 mm implants ( P < .05). There was no difference in insertion torque between 9 and 11 mm implants ( P > .05), nor was there a correlation between ISQ and insertion torque ( P > .05). In conclusion, longer implants (11 mm) presented a significant increase in ISQ values during the healing period when installed in areas previously submitted to maxillary sinus lift. This phenomenon was not observed for shorter implants (9 mm). Finally, no correlation was observed between ISQ and insertion torque.

Graft-Free Maxillary Sinus Floor Elevation: A Systematic Review and Meta-Analysis

BACKGROUND

This systematic review and meta-analysis aims to investigate survival rates of dental implants placed simultaneously with graft-free maxillary sinus floor elevation (GFSFE). Factors influencing amount of vertical bone gain (VBG), protruded implant length (PIL) in sinus at follow-up (PILf), and peri-implant marginal bone loss (MBL) are also evaluated.

METHODS

Electronic and manual searches for human clinical studies on simultaneous implant placement and GFSFE using the lateral window or transcrestal approach, published in the English language from January 1976 to March 2016, were conducted. The random-effects model and mixed-effect meta-regression were used to analyze weighted mean values of clinical parameters and evaluate factors that influenced amount of VBG.

RESULTS

Of 740 studies, 22 clinical studies were included in this systematic review. A total of 864 implants were placed simultaneously with GFSFE at edentulous sites having mean residual bone height of 5.7 ± 1.7 mm. Mean implant survival rate (ISR) was 97.9% ± 0.02% (range: 93.5% to 100%). Weighted mean MBL was 0.91 ± 0.11 mm, and it was significantly associated with the postoperative follow-up period (r = 0.02; R2 = 43.75%). Weighted mean VBG was 3.8 ± 0.34 mm, and this parameter was affected significantly by surgical approach, implant length, and PIL immediately after surgery (PILi) (r = 2.82, 0.57, 0.80; R2 = 19.10%, 39.27%, 83.92%, respectively). Weighted mean PILf was 1.26 ± 0.33 mm (range: 0.3 to 2.1 mm).

CONCLUSION

Within limitations of the present systematic review, GFSFE with simultaneous implant placement can achieve satisfactory mean ISR of 97.9% ± 0.02%.

The effect of 2 versus 4 implants on implant stability in mandibular overdentures: A randomized controlled trial

STATEMENT OF PROBLEM

Dental research is rich with articles that investigated the influence of host-site variables, some implant-related variables (implant length, diameter, taper, design, location, and surface topography), different loading protocols or surgical procedures, and measurement methodology on dental implant stability. However, the number of implants and its effect on implant stability remain unclear.

PURPOSE

The purpose of this randomized clinical trial was to investigate the influence of implant number on implant stability by comparing 2 versus 4 implants in mandibular implant overdentures.

MATERIAL AND METHODS

The trial included 20 participants with edentulous mandibular ridges. Participants were randomly assigned to 2 equal groups, a 4-implant (experimental) group consisting of 4 implants installed in lateral-canine and premolar regions; and a 2-implant (control) group, consisting of 2 implants in lateral-canine regions. Implant stability was measured using resonance frequency analysis at implant placement and then at 1, 3, 6, 9, and 12 months. The Student t test was used to compare the implant stability quotient (ISQ) values of the anterior implants in the 4-implant and 2-implant groups. One-way ANOVA followed by the post hoc Bonferroni test was used to compare ISQ values among the different follow-up periods within each group (α=.05).

RESULTS

Mean ISQ values for anterior implants in the 4-implant group were slightly higher than those recorded for the 2-implant group at all follow-up periods. However, these differences were not statistically significant (P>.05). Within-group comparison revealed an initial decrease in implant stability for all implants. This decrease was statistically significant for the 2-implant group (P<.001) and for posterior implants in the 4-implant group (P<.001). This was then followed by a gradual increase in ISQ values for all implants in both groups.

CONCLUSIONS

Increasing the number of implants from 2 to 4 in mandibular implant overdentures did not have a significant influence on implant stability.

Factors Affecting Dental Implant Stability Measured Using the Ostell Mentor Device: A Systematic Review

OBJECTIVES

The aim of this study was to review the literature on factors that may affect dental implant stability as measured with the Ostell mentor device.

MATERIALS AND METHODS

A systematic search of the literature was performed in Pubmed, Scopus, and Cochrane databases using dental implants, stability, and resonance frequency analysis as key words.

RESULTS

The most relevant randomized controlled trials and clinical trials (n = 39) were selected from among 264 articles.

CONCLUSIONS

Many factors can affect dental implant stability as measured with the Ostell mentor device. This may be a useful instrument for deciding the timing of implant loading, but additional research is required to establish the reliability and predictability of resonance frequency analysis for the future osseointegration of dental implants, which remains controversial.

Assessment of implant stability following sinus lift procedures with different grafting materials

OBJECTIVE

The objective of this research was to evaluate implant stability following sinus lift with two grafting materials, and to compare it with the results obtained for the implants placed in a pristine posterior maxilla.

MATERIALS AND METHODS

The study included 44 healthy patients with an existing indication for sinus lift procedure (test group). 46 implants were placed following sinus lift with a pure-phase beta-tricalcium phosphate, while 39 implants were placed following augmentation with 60% hydroxyapatite with 40% beta-tricalcium phosphate material. The control group consisted of 48 healthy patients who were treated with 85 implants but without bone augmentation in posterior maxilla. Astra Tech OsseoSpeed implants were placed in all subjects. Resonance frequency analysis was used in both groups for determining implant stability 4 months after insertion. A mean implant stability quotient (ISQ) was calculated on the basis of 3 measurements.

RESULTS

No statistical difference was observed in ISQ values of implants placed with and without augmentation procedure (p=0,789). Statistically significant difference was not found when ISQ values of implants placed following particular grafting material were compared with ISQ values of corresponding implants in a pristine bone (p=0.697 and p=0.402).

CONCLUSIONS

This study demonstrated that the implant stability is comparable among implants placed in the posterior maxilla regardless of sinus lift and grafting procedure. Implants placed in the grafted posterior maxilla can be predictably loaded as the implants placed in a non-grafted, pristine maxilla.

Single-staged vs. two-staged implant placement in vertically deficient alveolar ridges using bone ring technique - Part 2: implant osseointegration

OBJECTIVES

The aim of this study was to evaluate the osseointegration of implants placed in a single-staged compared to two-staged procedure using bone ring technique.

MATERIAL AND METHODS

In this study were used standardized, vertical alveolar bone defects in dogs. In the test group, dental implants (Straumann BL^® , Basel, Switzerland) were inserted simultaneously with bone ring technique. As control group served implants inserted 6 months following grafting. Implants of both groups were left for an osseointegration period of 3 and 6 months. The peri-implant bone loss and bone-to-implant contact within the bone ring and native bone were analyzed morphometrically. An explorative statistical analysis was performed.

RESULTS

The peri-implant bone level remained relatively stable within groups and between groups per given time period. Most of bone apposite on the implant surface in two groups was composed of newly formed bone. A nonparametric analysis of variance (ANOVA) revealed no significant advantage for two-staged implant placement for new and total bone, except for residual bone (P = .0084). Furthermore, two groups of implants performed similarly in bone ring and in native bone throughout the observation period.

CONCLUSIONS

In terms of osseointegration, both techniques are likely equally efficient in the present defect model. The single-staged implant placement with cortical bone grafts warrants further documentation in clinical studies.

Implant stability change and osseointegration speed of immediately loaded photofunctionalized implants

OBJECTIVES

This study evaluated the degree and rate of implant stability development for photofunctionalized dental implants in humans.

MATERIALS AND METHODS

Thirty-three implants (7 patients) placed in the maxilla and immediate loaded were evaluated. Photofunctionalization was performed by treating implants with ultraviolet for 15 minutes immediately before placement. Implant stability was assessed by measuring the implant stability quotient (ISQ) weekly starting from implant placement up to 3 months. Osseointegration speed index (OSI), defined as ISQ increase per month, was also evaluated.

RESULTS

The average ISQ for photofunctionalized implants at week 6 was 78.0, which was considerably higher than the average ISQ of 66.1, reported in literature for various as-received implants after a longer healing time of 2 to 6 months. No stability dip was observed for photofunctionalized implants regardless of the initial ISQ values. The OSI for photofunctionalized implants was 6.3 and 3.1 when their initial ISQ was 65 to 70 and 71 to 75, respectively, whereas the OSI values for as-received implants calculated from literature ranged from -3.0 to 1.17 with an average of -0.10.

CONCLUSIONS

Photofunctionalization accelerated and enhanced osseointegration of dental implants, providing novel and practical avenues for further advancement in implant therapy.