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

A Modified Ridge-Splitting Technique to Restore a Completely Edentulous Maxillary Arch With a Cement-Retained Implant Prosthesis

The present report describes a technique in which the maxillary bone was molded to the desired location using a series of instruments for ridge-splitting procedures. This technique aims to improve bone quality all around the implants at both the crest and apex locations. In some clinical scenarios, insufficient horizontal bone with less than 3 mm prevents implant placement. Thus, ridge splitting is a treatment of choice, and this technique creates bone expansion to form a better receptor site for endosteal implants. A case report is presented involving a completely edentulous 52-year-old male patient presented to the clinic with a horizontal bone defect. The patient complained of having difficulty eating and wants to improve his smile. In this clinical case, a modified ridge-splitting technique was employed, differing from the conventional procedure that uses mallets, chisels, or osteotomes. A lancet and spatula were used for precise ridge splitting, followed by the placement of four endosseous tapered implants-two on each side (Dentis USA, La Palma, USA). Each implant had a diameter of 3.7 mm and a length of 10 mm. These implants were clinically placed in a single visit, with a torque of 30 N/cm² applied to ensure secure fixation. To accommodate the patient's unique maxillary bone anatomy, 25-degree angulated abutments were chosen for the four implants, ensuring a common path of insertion, and optimal angulation for long-term stability and aesthetics. Subsequently, a cemented provisional dental prosthesis restoration was fitted, and the patient reported satisfaction with both function and aesthetics. After a period of five months of osseointegration, the stability of the implants was assessed using a resonance frequency analyzer, yielding positive results. The average resonance frequency values for the maxillary left (canine and premolar) were ISQ 68 and ISQ 71, respectively, while for the maxillary right (lateral incisor and premolar), the values were ISQ 69 and ISQ 73. These readings indicate satisfactory implant stability following the osseointegration process. The postoperative cone-beam computed tomography (CBCT) showed gain to the bone width besides better function and good results concerning the esthetics. This report describes a modified ridge-splitting technique with a predictable and satisfactory outcome that fulfilled the patient's demands. The presented approach overcomes the disadvantages of two-staged implant placement bone grafting procedures and is also a more affordable option for the patient. CBCT evaluation confirmed bone gain with minimal morbidity after the procedure.

Relevant Aspects of the Dental Implant Design on the Insertion Torque, Resonance Frequency Analysis (RFA) and Micromobility: An In Vitro Study

The major problems for the osseointegration of dental implants are the loosening of the screw that fixes the dental implant to the abutment and the micromovements that are generated when mechanical loads are applied. In this work, torque differences in the tightening and loosening of the connection screws after 1 cycle, 10 cycles and 1000 cycles for 4 dental implants with 2 external and 2 internal connections were analyzed. The loosening of 240 implants (60 for each system) was determined using high-precision torsimeters and an electromechanical testing machine. A total of 60 dental implants for each of the 4 systems were inserted into fresh bovine bone to determine the micromovements. The implant stability values (ISQ) were determined by RFA. The mechanical loads were performed at 30° from 20 N to 200 N. By means of the Q-star technique, the micromovements were determined. It was observed that, for a few cycles, the loosening of the screw did not exceed a loss of tightening of 10% for both connections. However, for 1000 cycles, the loss for the external connection was around 20% and for the internal connection it was 13%. The micromovements showed a lineal increase with the applied load for the implant systems studied. An external connection presented greater micromotions for each level of applied load and lower ISQ values than internal ones. An excellent lineal correlation between the ISQ and micromobility was observed. These results may be very useful for clinicians in the selection of the type of dental implant, depending on the masticatory load of the patient as well as the consequences of the insertion torque of the dental implant and its revisions.

Can the Immediate Implantation With Immediate Loading Achieve an Acceptable Esthetic Outcome? A Prospective Observational Clinical Study

The trending protocol in implantology aims at integrating the esthetic on par with function while reducing discomfort and treatment time with optimal results. The purpose of this study was to evaluate the pink esthetic score in sites treated by graftless instant implantation that was boosted by instant provisionalization with a 2 to 3 mm jumping distance. Thirty-five implants were inserted in the extraction sockets of teeth of 29 healthy qualified patients (22 females and 7 males) with an age range of 23 to 60 years [mean±SD age 41.11±9.9 y). Preoperative assessment was complemented clinically and radiographically for each patient. The used system was Medentika dental implant (Germany). Osstell implant stability quotient was used to measure implant stability at the time of surgery (baseline) and at 16 weeks. Four implants in 3 patients failed. The implant survival rate was 88.6%. The protocol of this study produced a significant decrease in the jumping distance which is 2 to 3 mm at cone-beam computed tomography evaluation with satisfactory esthetic outcomes clinically. Further comparative studies with long-term and larger samples are needed to confirm the conclusion of this study.

Clinical Validation of Dental Implant Stability by Newly Designed Damping Capacity Assessment Device during the Healing Period

Background and Objectives: To evaluate the stability of a dental implant and the effectiveness of a newly designed damping capacity assessment device by improving the number of blows and strength evaluated by a prospective clinical study. Materials and Method: The stability of dental implants was measured in 50 implants in a total of 38 patients. Measurements were performed using Anycheck and Periotest M devices, twice in total, divided into buccal and lingual directions. In addition, measurements were performed on the day of surgery, two weeks, one month, two months, and three months after surgery for a total of five times. After the standardization of the measured values, the differences and changes over time for each device were observed. Result: No difference in standardized values between the two devices was observed at any time point. In both devices, stability decreased at two weeks postoperatively but gradually increased thereafter. No differences were observed in the values according to the measurement direction. Conclusions: The damping capacity of Anycheck was similar to that of Periotest M. After a slight decrease in stability two weeks after implant placement, implant stability increased over time.

The Effects of Polyphenol, Tannic Acid, or Tannic Acid in Combination with Pamidronate on Human Osteoblast Cell Line Metabolism

Background: This study investigates the effect of tannic acid (TA) combined with pamidronate (PAM) on a human osteoblast cell line. Methods: EC₅₀ for TA, PAM, and different combination ratios of TA and PAM (25:75, 50:50, 75:25) were measured by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. The combination index value was utilized to analyze the degree of drug interaction, while trypan blue assay was applied to analyze the cells proliferation effect. The mineralization and detection of bone BSP and Osx genes were determined via histochemical staining and PCR test, respectively. Results: The EC₅₀ of osteoblasts treated with TA and a 75:25 ratio of TA and PAM were more potent with lower EC₅₀ at 0.56 µg/mL and 0.48 µg/mL, respectively. The combination of TA and PAM (75:25) was shown to have synergistic interaction. On Day 7, both TA and PAM groups showed significantly increased proliferation compared with control and combination groups. On Day 7, both the TA and combination-treated groups demonstrated a higher production of calcium deposits than the control and PAM-treated groups. Moreover, on Day 7, the combination-treated group showed a significantly higher expression of BSP and Osx genes than both the TA and PAM groups. Conclusion: Combination treatment of TA and PAM at 75:25 ameliorated the highest enhancement of osteoblast proliferation and mineralization as well as caused a high expression of BSP and Osx genes.

Effects of smoking on the bone alkaline phosphatase in peri-implant crevicular fluid and implant stability quotient around implants before loading

We aimed to examine the implant stability quotient (ISQ), alveolar bone level measurements (ABL), and bone alkaline phosphatase (BALP) in peri-implant crevicular fluid (PICF) around implants in smokers and non-smokers before loading in 3 months. 44 dental implants were placed into smoker and non-smoker patients equally. ISQ was measured at baseline and 3 months after surgery. The levels of PICF BALP and alveolar bone were measured. ISQ values significantly increased in smokers and non-smokers in the 3rd month (p < 0.05). ABL measurements were lower at 3 months compared to baseline in both groups (p < 0.05). Although ISQ and ABL values were higher in non-smokers than smokers at 3 months, the difference between the groups did not show any statistical significance. The PICF BALP levels in the 3rd month changed in both groups. But, these differences were insignificant. Although some of the measurements presented differences between the groups during the assessment periods, they were not indicative of the hazardous effects of smoking on bone healing around implants after surgery till functional loading in 3 months. However, smoking is an important factor to be considered for osseo-integration outcomes. Further studies are needed to clarify the influence of smoking on osseo-integration.

Dental implants' stability dependence on rotational speed and feed-rate of drilling: In-vivo and ex-vivo investigations

This study aimed to explore the effects of drilling rotational speed and feed-rate on the stability of dental implants through in-vivo and ex-vivo experiments. To this end, a total of 16 identical dental implants were inserted in the mandible of four dogs. The osteotomies were made with two drilling rotational speeds, i.e., 800 and 1500 rpm, and two different feed-rates, i.e., 1 and 2 mm/s. Implant stability quotients (ISQs) were recorded immediately after inserting implants and then each week for four subsequent weeks. Then, all animals were euthanized, and a bone sample containing the implants was extracted from each hemi-mandible for the pull-out test. A two-way ANOVA was performed for ISQs, and pull-out strengths (PoS), and the significance level was set to <0.05. The effect of rotational speed and feed-rate, used in this study, on the primary stability quotients was not significant (P > 0.05). Increasing the rotational speed from 800 to 1500 rpm significantly increased both ISQ and PoS values at the end of the 4^th week after the implantation (P = 0.022 and P = 0.001, respectively). Moreover, by decreasing the feed-rate from 2 to 1 mm/s, a significant increase in PoSs of the dental implants was observed four weeks after the implantation (P = 0.019). Results of this study showed that either by increasing drilling rotational speed, here from 800 to 1500 rpm, or by reducing feed-rate, here from 2 to 1 mm/s, the secondary stability would be reinforced. Further investigations are needed to see if and how the conclusions made in this study can be generalized.

Comparison of Implant Stability between Regenerated and Non-Regenerated Bone. A Prospective Cohort Study

Implant stability is one of the main indicators of successful osseointegration. Although it has been measured in numerous studies, there has been little research on implant stability in regenerated bone. The study compares primary and secondary stability between implants placed in regenerated versus native bone and evaluates the influence of bone quality on the results. Sixty implants were placed in 31 patients: 30 implants inserted in native bone (non-regenerated) after a healing period of at least 6 months post-exodontia and 30 inserted in regenerated bone at 6 months after grafting with xenograft. Resonance frequency analysis (RFA) was used to obtain implant stability quotient (ISQ) values at baseline (implant placement), 8 weeks, and 12 weeks. Statistically significant differences were found between implants placed in regenerated bone and those placed in native bone at all measurement time points (p < 0.05). ISQ values were significantly influenced by bone quality at baseline (p < 0.05) but not at 8 or 12 weeks. Greater stability was obtained in implants placed in native bone; however, those placed in regenerated bone showed adequate primary and secondary stability for prosthetic loading. Bone quality influences the primary but not secondary stability of the implants in both native and regenerated bone.

A Radiographic and Clinical Comparison of Immediate vs. Early Loading (4 Weeks) of Implants with a New Thermo-Chemically Treated Surface: A Randomized Clinical Trial

Background: Implant dentistry has evolved over time, resulting in better treatment outcomes for both patients and clinicians. The aim of this trial was to test whether the immediate loading of implants with a platform-switching design influences the marginal bone level, compared to four-week loading, after one year of follow-up. Moreover, a comparison of clinical data regarding implant survival, implant stability, and patient-reported outcome measures (PROMs) was conducted. Methods: Klockner^® VEGA^® implants with a ContacTi^® surface were placed in partially edentulous patients in the posterior areas. Group A received an immediately loaded prosthesis (one week) and Group B received an early-loaded prosthesis (four weeks). All abutments were placed at the time of surgery. Radiographic and clinical data were recorded. Results: Twenty-one patients were treated (35 implants). No implants were lost during the study. The final marginal bone level did not show differences between groups. The bone loss at 12 months at the implant level was 0.00 mm for both groups (median). The final implant quotient stability (ISQ) values did not differ between groups (median 73 and 70.25), nor did the other clinical parameters or PROMs. Conclusions: The results suggest that neither of the loading protocols with the implants used influenced the marginal bone level—not the osseointegration rate, clinical conditions, or PROMs.

The Effects of Smoking Cigarettes on Immediate Dental Implant Stability—A Prospective Case Series Study

Background: Smoking tobacco significantly affects the biology of periodontal tissues and contributes to the increased risk of peri-implant diseases. The aim of the study was to investigate whether smoking cigarettes affects the primary and secondary stability of maxillary dental implants, inserted into fresh sockets immediately after extraction. Methods: The study was conducted on 164 patients between the ages of 27–71 years old. 67 individuals smoked more than 20 cigarettes daily and 97 were non-smokers. 190 immediate implants were inserted in the maxilla. Immediate implantations were performed with simultaneous augmentation of the socket with xenogenic bone grafting material. In the posterior region, implants were inserted into the palatal alveolus. The stability of the implants was measured using Insertion Torque Value (ITV) and two types of devices: Periotest (PT) and Osstell (ISQ). Marginal bone loss was evaluated on cone beam computed tomography scans. Results: In an aesthetic area, the PT values at 6 months post-implantation were higher for smokers than non-smokers (p < 0.05), respectively. The ISQ values were significantly lower in smokers compared to non-smokers at 6 months post-implantation (p = 0.0226), respectively. In the posterior region PT values were higher in smokers both on the day of implantation (p = 0.0179), 6 months after surgery (p = 0.0003) as well as 24 months after surgery (p < 0.0001), as compared to non-smokers, respectively. Smokers revealed lower ISQ values than non-smokers (p = 0.0047) on the day of implantation, as well as 6 months after implantation (p = 0.0002), respectively. There were no significant differences in marginal bone loss after 18 months of loading between smokers and non-smokers in the aesthetic, as well as posterior regions (p > 0.05). ITV measurements were lower in smokers than non-smokers in the aesthetic (16.3 vs. 17.5 Ncm) and posterior area (16.8 vs. 17.9 Ncm). Conclusions: This study indicate that smoking cigarettes has a negative effect on the stability of immediate implants in the maxilla. Primary stability of immediate implants may be lower in the posterior area of the maxilla in smokers when compared to non-smokers, which may eliminate smokers from immediate implants in this region. Secondary stability of immediate implants may be lower in both the aesthetic and posterior areas in smokers compared to non-smokers, which may encourage the postponement of final crowns delivery at 6 months post op and the extension of the occlusaly temporary crowns use in some smoker cases.

Third-generation modular mandible endoprosthesis in Macaca fascicularis

The aim of this study was to develop a third-generation modular mandible endoprosthesis that would experience less stress concentration at its stems compared to earlier generations, thereby minimizing micromotion and achieving long-term stability. In this three-piece modular design, different degrees of movement were incorporated between the endoprosthesis module interfaces. It was hypothesized that this unique feature would minimize stress concentration at the stems and hence promote osseointegration during the early phase of implantation. The endoprosthesis system was made of commercially pure grade 4 titanium, machined and surface-treated, then sterilized and implanted in segmental mandible defects of nine Macaca fascicularis. Clinical, radiological, histological, and histomorphometric evaluations were performed 4 months post-implantation. The endoprosthesis systems with a degree of movement incorporated, exhibited superior performance compared to the rigid system: 30.9-34.8 times higher percentage bone-implant contact (P< 0.0001) and 3.4-4.1 times higher percentage bone area (P<0.0001), with osseointegration noted at the posterior stems. However, fibrous tissue encapsulation was noted around the majority of the anterior stems in all groups. Although the degree of movement was favourable for improving bone healing and stability of the endoprosthesis system, more work needs to be done to investigate other strategies to further reduce loading on the endoprosthesis to achieve predictable osseointegration at the stems.

Factors Influencing Primary and Secondary Implant Stability—A Retrospective Cohort Study with 582 Implants in 272 Patients

The success rate of dental implants depends on primary and secondary stability. We investigate predictive factors for future risk stratification models. We retrospectively analyze 272 patients with a total of 582 implants. Implant stability is measured with resonance frequency analysis and evaluated based on the implant stability quotient (ISQ). A linear regression model with regression coefficients (reg. coeff.) and its 95% confidence interval (95% CI) is applied to assess predictive factors for implant stability. Implant diameter (reg. coeff.: 3.28; 95% CI: 1.89–4.66, p < 0.001), implant length (reg. coeff.: 0.67, 95% CI: 0.26–1.08, p < 0.001), and implant localization (maxillary vs. mandibular, reg. coeff.: −7.45, 95% CI: −8.70–(−6.20), p < 0.001) are significant prognostic factors for primary implant stability. An increase in ISQ between insertion and exposure is significantly correlated with healing time (reg. coeff.: 0.11, 95% CI: 0.04–0.19). Patients with maxillary implants have lower ISQ at insertion but show a higher increase in ISQ after insertion than patients with mandibular implants. We observe positive associations between primary implant stability and implant diameter, implant length, and localization (mandibular vs. maxillary). An increase in implant stability between insertion and exposure is significantly correlated with healing time and is higher for maxillary implants. These predictive factors should be further evaluated in prospective cohort studies to develop future preoperative risk-stratification models.

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.

Dynamics of implant site preparation affecting the quality of osseointegrated implants in the maxillary aesthetic zone

PURPOSE

This study compared piezoelectric (PE) and conventional drills (CD) for maxillary aesthetic zone implant insertion.

MATERIAL AND METHODS

This was a prospective split-mouth study. Implants were divided into two groups. Beds were prepared with CDs in group I and PE in group II. The implant stability quotient (ISQ) of the mechanical implant stability (MIS) was measured intraoperatively. The ISQ of the biological implant stability (BIS) was recorded at postoperative second and fourth months. Marginal bone loss (MBL) and bone density (BMD) were measured in the first and second years after prosthetic loading. The osteotomy time was also documented for both techniques. P values <0.05 were considered significant.

RESULTS

Sixty implants in 30 patients were included. PE provided a significantly higher ISQ. All values were above 70 throughout the follow-up period. The mean of the ISQ for MIS was 63.78 ± 1.03 and 73.89 ± 1.05 in group I and group II, respectively (p = 0.003). PE needed significantly longer osteotomy time with a mean of 11.99 ± 0.839 min. The BIS quality had high stability in group II and medium stability in group I throughout the study period. Its values decreased in both groups. Group II had a lesser percentage of decrease. However, it was significant only at time intervals between intraoperative and two months' postoperative (p = 0.004). MBL and BMD demonstrated insignificant results.

CONCLUSION

The implant site preparation with PE devices should be preferred to CDs whenever possible, because they seem to enhance implant stability and osseointegration, especially at the initial stages of healing.

Does the manual insertion torque of smartpegs affect the outcome of implant stability quotients (ISQ) during resonance frequency analysis (RFA)?

Background

There is disagreement about the optimal torque for tightening smartpegs for resonance frequency analysis (RFA). Subjective finger pressure during hand tightening could affect the reliability of the resulting values. The aim of the current study was therefore to assess whether or not the insertion torque of a smartpeg magnetic device influences the implant stability quotient (ISQ) value during RFA.

Methods

Thirty self-tapping screw implants (XiVE S, Dentsply Sirona Implants, Bensheim, Germany) with a diameter of 3.8 mm and a length of 11 mm were inserted in three cow ribs with a bone quality of D1. The RFA value of each implant was measured (Ostell, FA W&H Dentalwerk, Bürmoos, Austria) in two orthogonal directions (mesial and buccal) after tightening the corresponding smartpeg type 45 with a mechanically defined value of 5 Ncm (Meg Torq device, Megagen, Daegu, South Korea) (test). Additionally, 4 different examiners measured the RFA after hand tightening the smartpegs, and the results were compared (control). Insertion torque values were determined by measuring the unscrew torque of hand seated smartpegs (Tohnichi Manufacturing Co. Ltd, Tokyo, Japan).

Results

The ISQ values varied from 2 to 11 Ncm by hand tightening and from 2 to 6 Ncm by machine tightening. The comparison of hand and machine tightening of smartpegs displayed only minor differences in the mean ISQ values with low standard deviations (mesial 79.76 ± 2,11, buccal 77.98 ± 2,) and no statistical difference (mesial p = 0,343 and buccal p = 0,890).

Conclusions

Manual tightening of smartpeg transducers allows for an objective and reliable determination of ISQ values during RFA.

Proliferation study and microscopy evaluation on the effects of tannic acid in human fetal osteoblast cell line (hFOB 1.19)

Tannic acid (TA) is a phenolic compound that might act directly on osteoblast metabolism. The study was performed to investigate the effects of TA on the proliferation, mineralization, and morphology of human fetal osteoblast cells (hFOB 1.19). The cells were divided into TA-treated, untreated, and pamidronate-treated (control drug) groups. Half maximal effective concentration (EC₅₀ ) values for TA and pamidronate were measured using MTT assay. The EC₅₀ of hFOB 1.19 cells treated with TA was 2.94 M. This concentration was more effective compared to the pamidronate (15.27 M). Cell proliferation assay was performed to compare cell viability from Day 1 until Day 14. The morphology of hFOB 1.19 was observed via inverted microscope and scanning electron microscope. Calcium (Ca) and phosphate (P) were assessed using energy-dispersive X-ray (EDX) analysis. Furthermore, the mineralization of hFOB 1.19 was determined by von Kossa staining (P depositions) and Alizarin Red S staining (Ca depositions). The number of cells treated with TA was significantly higher than the two control groups at Day 10 and Day 14. The morphology of cells treated with TA was uniformly fusiform-shaped with filopodia extensions. Besides, globular-like structures of deposited minerals were observed in the TA-treated group. In line with other findings, EDX spectrum analysis confirmed the presence of Ca and P. The cells treated with TA had significantly higher percentage of both minerals at Day 3 and Day 10 compared to the two control groups. In conclusion, TA enhances cell proliferation and causes cell morphology changes, as well as improved mineralization.

Systematic review of clinical and patient-reported outcomes following oral rehabilitation on dental implants with a tapered compared to a non-tapered implant design

BACKGROUND

Dental implants are available in different shapes.

AIMS

This systematic review aims to address whether tapered compared to non-tapered implants demonstrate similar clinical and patient-reported outcomes. The review follows the preferred reporting items for systematic reviews and meta-analyses (PRISMA) format.

MATERIALS & METHODS

We searched electronic databases including MEDLINE through PubMed and the Cochrane Central Register of Controlled Trials for randomized clinical trials (RCT) that compare tapered versus non-tapered implants with at least 10 treated participants and a minimum mean follow-up time of 3 years. There were no restrictions to a particular treatment indication or outcome measures. Two authors independently conducted screening, risk of bias assessment, and data extraction of eligible trials in duplicate. We applied the Cochrane risk of bias assessment tool to consider risk of bias.

RESULTS

We identified 18 different RCTs, of which three reported outcomes at 3 years or greater. The three trials described the results of 245 participants with 388 implants at 3 years, from the initially 306 participants with 494 implants at baseline. The three trials compared, respectively, two, two, and three different commercially available implant brands and reported only clinically insignificant differences. We judged all three trials to be at moderate risk of bias. The low number and heterogeneity of RCTs did not allow for meta-analyses.

DISCUSSION AND CONCLUSION

Appropriate professional judgment in clinical decision making must include a comprehensive diagnosis of the patient's jawbone quality and quantity and consideration of osteotomy protocol in accordance with the patient's treatment preferences, where the shape of the dental implant is only one contributory factor.

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.

Minimally Invasive Ponto Surgery Versus the Linear Incision Technique With Soft Tissue Preservation for Bone Conduction Hearing Implants: A Multicenter Randomized Controlled Trial

OBJECTIVE

To compare the surgical outcomes of the Minimally Invasive Ponto Surgery (MIPS) technique with those of the linear incision technique with soft-tissue preservation for bone-anchored hearing systems (BAHS).

DESIGN

Sponsor-initiated multicenter, open, randomized, controlled clinical trial.

SETTING

Maastricht University Medical Centre, Ziekenhuisgroep Twente and Medisch Centrum Leeuwarden, all situated in The Netherlands.

PARTICIPANTS

Sixty-four adult patients eligible for unilateral BAHS surgery.Interventions Single-stage BAHS surgery with 1:1 randomization to the linear incision technique with soft-tissue preservation (control) or the MIPS (test) group.

PRIMARY AND SECONDARY OUTCOME MEASUREMENTS

Primary objective: compare the incidence of inflammation (Holgers Index ≥ 2) during 12 weeks' follow-up after surgery. Secondary objectives: skin dehiscence, pain scores, loss of sensibility around the implant, soft-tissue overgrowth, skin sagging, implant extrusion, cosmetic results, surgical time, wound healing and Implant Stability Quotient measurements.

RESULTS

Sixty-three subjects were analyzed in the intention-to-treat population. No significant difference was found for the incidence of inflammation between groups. Loss of skin sensibility, cosmetic outcomes, skin sagging, and surgical time were significantly better in the test group. No statistically significant differences were found for dehiscence, pain, and soft-tissue overgrowth. A nonsignificant difference in extrusion was found for the test group. The Implant Stability Quotient was statistically influenced by the surgical technique, abutment length, and time.

CONCLUSION

No significant differences between the MIPS and the linear incision techniques were observed regarding skin inflammation. MIPS results in a statistically significant reduction in the loss of skin sensibility, less skin sagging, improved cosmetic results, and reduced surgical time. Although nonsignificant, the implant extrusion rate warrants further research.

Effect of Growth Hormone Supplementation on Osseointegration: A Systematic Review and Meta-analyses

OBJECTIVES

The aim of this study was to assess whether growth hormone (GH) replacement therapy can enhance implant osseointegration.

MATERIALS AND METHODS

A systematic literature search was conducted from 1982 to March 2016. A structured search using the keywords "growth hormone," "implants," and "osseointegration" was performed to identify preclinical and clinical in vivo controlled studies and was followed by a 2-phase search strategy. Initially, 31 potentially relevant articles were identified. After removal of duplicates and screening by title and abstract, 10 potential studies were included. Studies were assessed for bias and data were synthesized using a random-effects meta-analysis model.

RESULTS

All studies were preclinical animal trials, and the follow-up period ranged from 2 to 16 weeks. Seventy percent of the included studies reported an increase in bone-to-implant contact in animals receiving GH compared with controls. Meta-analysis showed a significant mean difference for bone to implant between GH groups versus controls (no GH supplementation) of 10.60% (95% confidence interval: 3.79%-17.41%) favoring GH administration.

CONCLUSION

GH treatment seems to promote osseointegration around implants in preclinical studies; however, these findings must be assessed in highly controlled human clinical trials as a number of confounding factors may have influenced the outcomes of the included studies.

Autogenous teeth used for bone grafting: A systematic review

BACKGROUND

Recently, bone graft materials using permanent teeth have come to light, and clinical and histological outcomes of this material have been confirmed by some studies. The aim of this systematic review was to evaluate the reliability of the autogenous tooth bone graft material applied to alveolar ridge augmentation procedures.

MATERIAL AND METHODS

A systematic review of literature was conducted analyzing articles published between 2007 and 2017. The following four outcome variables were defined: a) implant stability b) post-operative complication c) evaluation of implant survival and failure rates, and d) histological analysis. A total of 108 articles were identified; 6 were selected for review. Based on the PICO (problem, intervention, comparison, outcome) model, the chief question of this study was: Can patients with alveolar ridge deficiency be successfully treated with the autogenous teeth used as bone graft?

RESULTS

The mean primary stability of the placed implants was 67.3 ISQ and the mean secondary stability was 75.5 ISQ. The dehiscence of the wound was the most frequent complication with a rate of 29.1%. Of the 182 analyzed implants, the survival rate was 97.7% and the failure rate was 2.3%. In the histological analysis, most of studies reported bone formation.

CONCLUSIONS

There is insufficient evidence regarding the effects of autogenous teeth used for bone grafting to support any definitive conclusions, although it has been shown clinically safe and good bone forming capacity, and good results are shown about implant stability.

The Use of Cone Beam Computed Tomography in Assessing the Insertion of Bone Conduction Hearing Implants

OBJECTIVE

This study aimed to compare postoperative cone beam CT (CBCT) imaging to implant stability quotient (ISQ) measurement and direct caliper measurements as a suitable technique to assess bone conduction hearing implant (BCHI) seating and insertion depth.

METHODS

In vitro, BCHIs were completely (n = 9) and partially inserted (n = 9) in bone blocks of different densities and subsequently scanned. Scans were processed using 3DSlicer 4.3.1 and Mathematica 10.3. ISQ measurements were obtained for all BCHIs mounted with different abutment lengths (9, 12, and 14 mm). CBCT imaging was performed for patients with a clinical indication.

RESULTS

In vitro, 95% prediction intervals for partially inserted and completely inserted BCHIs were determined. ISQ values significantly decreased with partial insertion, low-density artificial bone, and longer abutment lengths. Evaluation of in vitro and in vivo 3D models allowed for assessment of insertion depth and inclination.

CONCLUSION

CBCT imaging allows to study implant seating and insertion depth after BCHI surgery. This can be useful when visual confirmation is limited. It is possible to distinguish a partial BCHI insertion from a complete insertion in artificial bone blocks. This technique could prove to be a valuable research tool. In vitro, ISQ values for Ponto BCHIs relate to abutment length, insertion depth, and artificial bone density.