Periosteum-derived Micrografts for bone regeneration.

Bone regeneration is currently one of the most widely researched topics in regenerative medicine. Several bone-grafting materials have been introduced and compared. However, the limitations of the currently available grafts have led researchers to investigate new materials to be used. In contrast, the periosteum performs endogenous bone regeneration as seen in physiological bone fracture repair, and transplanted periosteum has been used to induce bone regeneration in animal models. Although many of the introduced bone grafting materials have not been clinically evaluated, the use of the periosteum for bone regeneration has been documented in several clinical situations. Recently, the Micrograft concept, which was initially used to treat burn patients, where the tissue sample is cut into smaller pieces to expand the area that they can cover, has been applied to oral periosteal tissue for inclusion in scaffolds for bone defect healing, and was evaluated in various clinical bone augmentation procedures. This article first presents a brief overview of some of the commonly used bone grafts and their limitations. Next, it provides background information on the periosteum, including its histology and the cell biology and signaling involved in its osteogenic effect, periosteum-derived Micrografts, their osteogenic potential, and their recent clinical applications for bone augmentation.

Stability of guided bone regeneration with two ratios of biphasic calcium phosphate at implant sites in the esthetic zone: A randomized controlled clinical trial.

AIMS: The aim of this randomized, double-blind, clinical trial was to compare the stability of the horizontal dimensions (facial bone thickness) of augmented bone using biphasic calcium phosphate (BCP) with hydroxyapatite/ß-tricalcium phosphate ratio of either 60/40 or 70/30. MATERIALS AND METHODS: Sixty dental implants placed with contour augmentation in the esthetic zone were randomized to 60/40 BCP (n = 30) or 70/30 BCP (n = 30). Cone-beam computed tomographic was used to assess facial bone thickness post-implantation and 6 months later at implant platform and 2, 4, and 6 mm apical to it. RESULTS: The percentage of horizontal dimension reduction was 23.64%, 12.83%, 9.62%, and 8.21% in 70/30 BCP group, while 44.26%, 31.91%, 25.88%, and 21.49% in 60/40 BCP group at the level of the implant platform and 2, 4, and 6 mm apical, respectively. Statistically significant difference was found at 6 months at all levels of measurement (p-value < .05). CONCLUSIONS: BCP bone grafts with HA/ß-TCP ratio of 60/40 and 70/30 showed comparable outcomes for contour augmentation simultaneously with implant placement. Interestingly, the 70/30 ratio was significantly superior in maintaining facial thickness and showed more stable horizontal dimensions of the augmented site.

Computer-assisted and robotic implant surgery: Assessing the outcome measures of accuracy and educational implications.

OBJECTIVE: This scoping review aimed to (1) critically evaluate the outcomes measures used to assess the accuracy of implant placement with Computer Assisted Implant Surgery (CAIS) and (2) review the evidence supporting the efficient implementation of CAIS in training and education of clinicians. METHODS: A scoping literature review was conducted aiming to identify (a) clinical trials assessing accuracy of implant placement with CAIS, and (b) clinical trials or simulation/cadaver studies where CAIS was utilised and assessed for the training/education of clinicians. Studies since 1995 were assessed for suitability and data related to the outcomes measures of accuracy and educational efficacy were extracted and synthesised. RESULTS: Accuracy of CAIS has been mainly assessed through surrogate measures. Individual clinical trials have not shown any difference between static and dynamic CAIS, but recent meta-analyses suggest an advantage of dynamic CAIS in reducing angular deviation. The combination of static and dynamic CAIS might offer higher accuracy than each of the two used alone. Dynamic CAIS is suitable for novice surgeons and might even have added value as an education tool for implant surgery, although mastering the technique requires longer training than static. CONCLUSION: Meta-analyses of large samples, new and diverse outcomes measures, as well as benchmarking of levels of accuracy with specific clinical outcomes will help to better understand the potential and limitations of CAIS. Dynamic CAIS is suitable for novice operators, but educational interventions distributed over longer periods of time will be required for mastery of the process.

The accuracy of implant placement using a combination of static and dynamic computer-assisted implant surgery in fully edentulous arches: A prospective controlled clinical study.

OBJECTIVE: To compare the accuracy of implant position, using a combination of static and dynamic computer-assisted implant surgery (CAIS), with either static, dynamic, or freehand implant placement, in fully edentulous arches. MATERIALS AND METHODS: Twenty-one patients with a total of 88 fixtures were included. Implants were divided equally into four groups: a combination of static and dynamic CAIS (SD group), static CAIS (S group), dynamic CAIS (D group), and freehand placement (FH group). Angular deviation, as well as the 3D platform and apex deviations, were measured for all groups. Furthermore, the direction of implant deviation was recorded and compared. RESULTS: The FH group showed significantly more deviation compared to all groups, considering all the aspects, and at both the implant platform and apex. A significant difference in angular deviation between the SD and S groups (p < .001), and between the SD and D groups (p < .001) was noted, favoring the SD group. When evaluating implant distribution, the FH group showed a tendency towards the buccal, apical, and distal directions at platform and apex, while in the D group, implants shifted more to the buccal. In contrast, the SD group did not show a trend toward any specific direction. The S and SD groups did not show a statistical significance considering any direction. CONCLUSIONS: The combination of static and dynamic CAIS increases the accuracy of implant placement in fully edentulous arches when compared with either static or dynamic CAIS alone, as well as freehand placement.

Accuracy of implant placement with a combined use of static and dynamic computer-assisted implant surgery in single tooth space: A randomized controlled trial.

OBJECTIVE: To compare implant accuracy of combined static and dynamic (SD) computer-assisted implant surgery (CAIS) with static (S), dynamic (D) CAIS, and freehand surgery (FH) for single implant placement. MATERIALS AND METHODS: One hundred and twenty patients were randomized into four groups. Implants were placed using both stereolithographic surgical guide and dynamic navigation in the SD group, stereolithographic surgical guide in S group, dynamic navigation in D group, and conventional freehand in FH group. Analysis of deviation between planned and final implant position, as well as K means analysis was conducted for implant deviation at platform, apex, and angle (primary outcomes) and directional distribution at platform and apex (secondary outcome). RESULTS: Significant differences were found among the four groups (p < .001): The 3D deviation at the platform (mm) of SD, S, D, and FH groups was 0.62 ± 0.50, 1.06 ± 0.67, 1.02 ± 0.45, and 1.48 ± 0.68, respectively, at apex (mm) was 0.75 ± 0.57, 1.40 ± 0.71, 1.28 ± 0.50, and 2.18 ± 0.95, respectively, and angle (degrees) was 1.24 ± 1.41, 3.18 ± 2.04, 3.28 ± 1.57, and 7.50 ± 4.06, respectively. Deviation at the platform of FH group was significantly more toward mesial (p = .026) and coronal (p = .014) direction, while at the apex, toward distal (p = .004) and lingual (p = .002) than SD group. CONCLUSION: The use of combined static and dynamic CAIS provided significantly higher accuracy than the two alone and freehand surgery for single implant placement.

Can computer-assisted implant surgery improve clinical outcomes and reduce the frequency and intensity of complications in implant dentistry? A critical review.

Computer-assisted implant surgery (CAIS), either static or dynamic, is well documented to significantly improve the accuracy of implant placement. Whether the increased accuracy leads to a corresponding improvement in clinical outcomes has not yet been systematically investigated. The aim of this critical review was to investigate whether the use of CAIS can lead to reduction of complications as well as improved clinical and patient-reported outcomes (PROs) when compared with conventional freehand implant surgery. A comprehensive online search was conducted to identify studies where implants were installed with static computer-assisted implant surgery (s-CAIS)or dynamic computer-assisted implant surgery(d-CAIS) or combinations of the two, either compared with conventional free-hand implant placement or not. Seventy-seven studies were finally included in qualitative analysis, while data from three studies assessing postsurgical pain were suitable for a meta-analysis. Only a small number of the available studies were comparative. The current evidence does not suggest any difference with regard to intraoperative complications, immediate postsurgical healing, osseointegration success, and survival of implants placed with CAIS or freehand protocols. Intraoperative and early healing events as reported by patients in randomized clinical trials (RCTs) did not differ significantly between CAIS used with flap elevation and conventional implant placement. There is limited evidence that increased accuracy of placement with CAIS is correlated with superior esthetic outcomes. Use of CAIS does not significantly reduce the length of surgeries in cases of single implants and partially edentulous patients, although there appears to be a more favorable impact in fully edentulous patients. Although CAIS alone does not seem to improve healing and the clinical and PRO, to the extent that it can increase the utilization of flapless surgery and predictability of immediacy protocols, its use may indirectly lead to substantial improvements in all of the above parameters.

Gene expression, micro-CT and histomorphometrical analysis of sinus floor augmentation with biphasic calcium phosphate and deproteinized bovine bone mineral: A randomized controlled clinical trial.

AIMS: The aim of this randomized controlled clinical trial was to compare the gene expression, micro-CT, histomorphometrical analysis between biphasic calcium phosphate (BCP) of 70/30 ratio and deproteinized bovine bone mineral (DBBM) in sinus augmentation. MATERIALS AND METHODS: Twenty-four patients in need for sinus floor augmentation through lateral approach were randomized into BCP 70/30 ratio or DBBM. After at least 6 months of healing, a total of 24 bone specimens were collected from the entire height of the augmented bone at the area of implant placement and underwent micro-CT, histomorphometric and gene expression analysis. The 12 bone specimens of BCP 70/30 ratio were equally allocated to micro-CT and histologic analysis (test group, n = 6) and gene expression analysis (test group, n = 6). Similarly, the 12 bone specimens of DBBM were also allocated to micro-CT and histologic analysis (control group, n = 6) and gene expression analysis (control group, n = 6). The newly formed bone, remaining graft materials and relative change in gene expression of four target genes were assessed. RESULTS: The micro-CT results showed no statistically significant difference in the ratio of bone volume to total volume (BV/TV ratio) for the two groups (BCP 41.51% vs. DBBM 40.97%) and the same was true for residual graft material to total volume (GV/TV ratio, BCP 9.97% vs. DBBM 14.41%). Similarly, no significant difference was shown in the histological analysis in terms of bone formation, (BCP 31.43% vs. DBBM was 30.09%) and residual graft area (DBBM 40.76% vs. BCP 45.06%). With regards to gene expression, the level of ALP was lower in both groups of bone grafted specimens compared with the native bone. On the contrary, the level of OSX, IL-1B and TRAP was higher in augmented bone of both groups compared with the native bone. However, the relative difference in all gene expressions between BCP and DBBM group was not significant. CONCLUSIONS: The BCP, HA/ß-TCP ratio of 70/30 presented similar histological and micro-CT outcomes in terms of new bone formation and residual graft particles with DBBM. The gene expression analysis revealed different gene expression patterns between augmented and native bone, but showed no significant difference between the two biomaterials.

The clinical efficacy of the allogenic demineralized dentin matrix graft for implant placement: a systematic review.

PURPOSE: The Allogenic Demineralized Dentin Matrix (Allo-DDM) has been introduced as a new grafting material, and several investigations were conducted, showing its efficacy in bone augmentation. The objective of this systematic review was to evaluate the available literature on the Allo-DDM, revealing its clinical performance when used for implant placement procedures. METHODS: This study is registered in the PROSPERO database (number: CRD42021264885, date: 30/7/2021). Four databases, as well as the grey literature, were searched, selecting human studies where the Allo-DDM was applied to augment implant-recipient sites. RESULTS: Six articles were included. The total number of implants placed in Allo-DDM-grafted sites was 149. Mean implant stability quotient values (ISQ) were 60.4 and 68.67 for the primary and secondary ISQ, respectively (data from one study). Buccal marginal bone loss around implants was approximately 1.46 mm after 24 months of prosthetic loading (data from one study). Two studies documented a total of 6 cases of dehiscence of the grated area, however, not affecting early implant success. Histological findings from all studies showed new bone formation around the graft particles. CONCLUSION: A low number of publications are available, presenting only preliminary results, thus the long-term success/survival of implants still needs to be further explored. Moreover, the possibility of bony dehiscence with the use of this material should be investigated. Within these limitations, the Allo-DDM could be a possible alternative to other grafting materials used for bone augmentation and implant placement. Nevertheless, considering this limited evidence, future studies are necessary to confirm this conclusion.

The role of hemostatic agents after tooth extractions: A systematic review and meta-analysis.

BACKGROUND: Hemostatic agents are used to control bleeding after tooth extraction and have been compared with conventional measures (that is, sutures or gauze pressure) in several studies. The objective of this systematic review was to evaluate the benefits of topical hemostatic agents for controlling bleeding after tooth extractions, especially in patients receiving antithrombotic therapy. TYPES OF STUDIES REVIEWED: The authors conducted a literature search in MEDLINE (PubMed), Scopus, and the Cochrane Central Register of Controlled Trials, including prospective human randomized clinical trials in which researchers compared hemostatic agents with conventional methods and reported the time to achieve hemostasis and postoperative bleeding events. RESULTS: Seventeen articles were eligible for inclusion. Hemostatic agents resulted in a significantly shorter time to achieve hemostasis in both healthy patients and patients taking antithrombotic drugs (standardized mean difference, -1.02; 95% CI, -1.70 to -0.35; P = .003 and standardized mean difference, -2.30; 95% CI, -3.20 to -1.39; P < .00001, respectively). Significantly fewer bleeding events were noted when hemostatic agents were used (risk ratio, 0.62; 95% CI, 0.44 to 0.88; P = .007). All forms of hemostatic agents (that is, mouthrinse, gel, hemostatic plug, and gauze soaked with the agent) had better efficacy in reducing the number of postoperative bleeding events than conventional hemostasis measures, except for hemostatic sponges. However, this was based on a small number of studies in each subgroup. CONCLUSIONS: The use of hemostatic agents seemed to offer better bleeding control after tooth extractions in patients on antithrombotic drugs than conventional measures. PRACTICAL IMPLICATIONS: Findings of this systematic review may help clinicians attain more efficient hemostasis in patients requiring tooth extraction. This systematic review is registered in the PROSPERO database. The registration number is CRD42021256145.

Training of novice surgeons using dynamic computer assisted dental implant surgery: An exploratory randomized trial.

BACKGROUND: Dynamic Computer Assisted Implant Surgery (CAIS) systems have been shown to improve accuracy of implant placement, thus training in the use of such systems is becoming increasingly important. There is a scarcity of research on how to implement dynamic CAIS training in the settings of postgraduate university education. PURPOSE: To determine the effectiveness of two modes of CAIS training programs on motor skill acquisition of novice surgeons. MATERIALS AND METHODS: Thirty-six postgraduate students without experience in dynamic CAIS systems were randomly assigned to a distributed training program (3 training sessions over 3 days) or a massed training (3 training sessions over the same day). A post-test involving the placement of one implant was conducted for both groups, 7 days after completion of the training. Surgical time and implant accuracy were recorded and analyzed, using independent t-tests, with 0.05 significant level. RESULTS: Both groups reached the accuracy benchmarks expected by current standards in the use of CAIS. No significant differences with regards to accuracy were found between the groups, but a trend was documented favoring performance of distributed (mean difference-0.4, 95% confidence interval-0.7-0.1) in the accuracy at platform level. Distributed training students performed faster than massed for the third trial (mean difference-95.0, 95% confidence interval-178.8 to -11.2). CONCLUSIONS: Novice students reached the accuracy benchmarks with the use of CAIS through both a massed and a distributed training program, while there was a strong but marginally not significant trend for higher accuracy in the distributed group. Students who received the training in the distributed format over the process of different days, performed faster. Trial registered in Thai Clinical Trials Registry: https://www.thaiclinicaltrials.org/show/TCTR20230109002. This clinical trial was not registered prior to participant recruitment and randomization.

The lack of keratinized mucosa as a risk factor for peri-implantitis: a systematic review and meta-analysis.

This study aimed to investigate the effect of the lack of keratinized mucosa on the risk of peri-implantitis, while also accounting for possible confounding factors. A literature search was conducted in PubMed and Scopus, including human studies that assessed the presence and width of keratinized mucosa in relation to the occurrence of peri-implantitis. Twenty-two articles were included, and 16 cross-sectional studies we meta-analyzed. The prevalence of peri-implantitis was 6.68-62.3% on patient-level and 4.5-58.1% on implant-level. The overall analysis indicated that the lack of keratinized mucosa was associated with a higher prevalence of peri-implantitis (OR = 2.78, 95% CI 2.07-3.74, p < 0.00001). Similar results were shown when subgroup analyses were performed, including studies with a similar case definition of peri-implantitis (Marginal Bone Loss, MBL ≥ 2 mm) (OR = 1.96, 95% CI 1.41-2.73, p < 0.0001), fixed prostheses only (OR = 2.82, 95% CI 1.85-4.28, p < 0.00001), patients under regular implant maintenance (OR = 2.08, 95% CI 1.41-3.08, p = 0.0002), and studies adjusting for other variables (OR = 3.68, 95% CI 2.32-5.82, p = 0.007). Thus, the lack of keratinized mucosa is a risk factor that increases the prevalence of peri-implantitis and should be accounted for when placing dental implants.

The effect of different hemostatic agents following dental extraction in patients under oral antithrombotic therapy: a network meta-analysis.

This network meta-analysis was done to thoroughly evaluate the available literature on the use of different hemostatic agents for dental extraction in patients under oral antithrombotic therapy, aiming to identify the agent with the best/worst performance in bleeding control. Considering that such patients have a higher risk of bleeding, choosing the right hemostatic is essential. Twenty-three randomized clinical trials articles were included after completing the literature search. Cyanoacrylate tissue adhesive showed a reduction in the odds of postoperative bleeding events compared with conventional methods (i.e., gauze/cotton pressure, sutures), with a tendency toward a statistical significance (OR 0.03, P = 0.051). Tranexamic acid was the only agent that demonstrated a significantly lower risk of developing postoperative bleeding events (OR 0.27, P = 0.007). Interestingly, chitosan dental dressing and collagen plug had the shortest time to reach hemostasis. However, they ranked last among all hemostatic agents, regarding bleeding events, revealing higher odds than conventional measures. Therefore, it is concluded that the use of cyanoacrylate tissue adhesive and tranexamic acid gives favorable results in reducing postoperative bleeding events following dental extractions. Although chitosan dental dressing and collagen exhibited a faster time to reach hemostasis, they led to a higher occurrence of bleeding events.

Effect of chemical and electrochemical decontamination protocols on single and multiple-used healing abutments: A comparative analysis of contact surface area, micro-gap, micro-leakage, and surface topography.

INTRODUCTION: Although the combined use of chemical and electrochemical decontamination protocols can completely remove contaminants from the surfaces of one-time used healing abutments (HAs), their effectiveness in multiple-used HAs remains unknown. We aimed to investigate the effect of reused HAs frequency on the implant-HA contact surface area, micro-gap, microleakage, and surface topography following chemical and combined chemical and electrochemical decontamination protocols. METHODS: Ninety bone level titanium implants were assembled with 90 bone level HAs, in which 80 contaminated HA samples were collected from human participants. The retrieved HAs were randomly divided into two groups according to the cleaning protocol: ultrasonication with 5.25% NaOCl solution for 15 min and steam autoclaving (group I); ultrasonication with 5.25% NaOCl solution for 15 min, followed by electrochemical cleaning and steam autoclaving (group II). The control group (group III) comprised 10 new unused HAs. The cleaning protocol was applied after each insertion as follows: (a) single-use and cleaning, (b) double-use and double cleaning cycles, (c) triple-use and triple cleaning cycles, and (d) more than triple-use and more than triple cleaning cycles. The contact surface area and micro-gap were assessed with micro-computed tomography scanning technique, microleakage test using 2% methylene blue staining, surface morphology with scanning electron microscopy, and surface elemental composition with energy-dispersive X-ray spectroscopy analysis. RESULTS: Group Id exhibited the smallest contact surface area. The values of the micro-gap volumes and microleakage were significantly different (p < 0.001) in the descending order of Id > Ic > Ib > IId > Ia, IIa, and III. Morphological evaluation of Groups IIa, IIb, and IIc revealed that residual biological debris was optimally removed without altering their surface properties. CONCLUSIONS: Chemical and electrochemical decontamination protocols are more effective than NaOCl cleaning methods, particularly for multiple consecutive uses with better decontamination levels, which decreases micro-gap volume and microleakage without surface alterations. Although the use of combined decontamination protocols for the contact surface area at the implant-HA interface showed comparable results with the control, change in the contact surface area was observed following the NaOCl cleaning methods. Therefore, titanium HA reuse can be considered in multiple times, if they are cleaned and sterilized using combined chemical and electrochemical decontamination protocols.

Comparative study of stability between two different fixation systems after orthognathic surgery in mandibular prognathism skeleton.

OBJECTIVE: This study is intended to compare the skeleton stability of bioabsorbable and titanium systems after orthognathic surgery in mandibular prognathism patients. STUDY DESIGN: A Retrospective study of 28 mandibular prognathism patients who underwent BSSRO setback surgery at Chulalongkorn University. Both titanium and the bioabsorbable group would take lateral cephalometrics immediately postoperative in 1-week(T0), 3(T1), 6(T2), and 12(T3) months. These radiographs were analyzed with Dolphin imaging programTM. The vertical, horizontal, and angular indices were measured. To compare immediately postoperative and follow-up periods within the group, the Friedman difference was used, and the Man-Whitney U test was used between the two groups. RESULT: The measurements within the group presented no statistically significant differences. But this study showed that at T0-T1, there was a statistically significant difference between the two groups in the mean of Me in horizontal linear measurement. T0-T2 found differences between Me in both horizontal and vertical linear measurements, and the difference between ANB. The differences between B-point, Pog, and Me in vertical linear measurements at T0-T3 were also reported. CONCLUSION: The significant difference values were within the normal range which indicated that using the bioabsorbable system could be well maintained as well as the titanium system. STATEMENT OF CLINICAL RELEVANCE: The second operation for removing titanium plate and screw after conventional orthognathic surgery may leads patient discomforts. While a resorbable system might be the role change if the stability is place on the same level.

Understanding the Stress Distribution on Anatomic Customized Root-Analog Dental Implant at Bone-Implant Interface for Different Bone Densities.

The aim of this study is to assess the stress distribution on the bone tissue and bone-implant interface of a customized anatomic root-analog dental implant (RAI) by means of finite element analysis (FEA) for different types of bone density. A mandibular right second premolar was selected from the CBCT database. A DICOM file was converted to an STL file to create a CAD model in FEA software. The bone boundary model was created, while bone density types I-IV were determined. Von Mises stress was measured at bone tissues and bone-implant interfaces. To validate the models, the RAI was 3D printed through a laser powder-bed fusion (L-PBF) approach. The results revealed that all RAI designs could not cause plastic deformation or fracture resulting in lower stress than the ultimate tensile stress of natural bone and implant. Compared to a conventional screw-type implant, RAIs possess a more favorable stress distribution pattern around the bone tissue and the bone-implant interface. The presence of a porous structure was found to reduce the stress at cancellous bone in type IV bone density.

The stability of tetracalcium phosphate/titanium implants: A short-term follow-up study.

Background/purpose: Bioceramic tetracalcium phosphate (TTCP) is used as a surface modifier on the implant surface and the clinical studies on this surface modification are still limited. The objective of this clinical study was to investigate short-term implant stability of titanium implant surfaces being modified through sandblasting and acid etching (SLA), followed by TTCP sintered bioceramic anchoring. Materials and methods: A total of 20 patients who had single tooth space were included in this study. Surface modification by SLA plus with TTCP on Ti implants with a diameter of 4.0 mm and lengths of 10 and 11.5 mm were placed. Implant stability quotient (ISQ) value was measured immediately (ISQ0) and one month (ISQ1), two months (ISQ2), three months (ISQ3), and four months (ISQ4) after implantation. Subgroup analysis was defined to location (maxilla, mandible) and bone density (soft or hard bone). Statistical analysis was performed using Friedman test and Mann-Whitney U test. Results: The mean ISQ values with standard deviation at the different time points of ISQ0 to ISQ4 were 60.03 ± 14.12, 53.48 ± 15.24, 58.91 ± 14.43, 63.14 ± 12.22, and 63.50 ± 13.61, respectively. The results showed significant differences between the ISQ1 and ISQ3 groups and between the ISQ1 and ISQ4 groups. On the other hand, there was no statistical differences between the maxilla and mandible as well as between soft and hard bone types in all implant groups. Conclusion: TTCP/titanium implant showed favorable stability in short-term ISQ values over 4 months. The locations and bone types demonstrated no effect on implant stability.

Comparison of the accuracy of implant placement using different drilling systems for static computer-assisted implant surgery: A simulation-based experimental study.

BACKGROUND: Different designs of surgical drilling systems have been developed for the purpose of static Computer-Assisted Implant Surgery (sCAIS), but there is at present little understanding of how design principles affect the accuracy of implant placement. PURPOSE: The aim of this in vitro study was to compare the accuracy of implant placement among five drilling systems of sCAIS in a controlled experimental setting. MATERIALS AND METHODS: Twenty-five 3D printed models with two edentulous bilateral premolar spaces were allocated to five different drilling systems: group A: sleeve-in-sleeve, group B: sleeve-in-sleeve with self-locking, group C: mounted sleeve-on-drill, group D: integrated sleeve-on-drill with metal sleeve in the guide, group E: integrated sleeve-on-drill without metal sleeve. Models were scanned with CBCT and optical scanner. All implants were digitally planned and 10 implants placed with sCAIS in each group. Postoperative 3D deviation of placed vs planned position was measured by means of platform, apex and angular deviation. Data was analyzed using Kruskal-Wallis test (P ≤ .05). Pairwise comparisons were tested with Dunn's test with adjusted P values. RESULTS: The overall platform deviation ranged from 0.42 ± 0.12 mm (group B) to 1.18 ± 0.19 mm (group C). The overall apex deviation ranged from 0.76 ± 0.22 mm (group B) to 1.95 ± 0.48 mm (group D). The overall angular deviation ranged from 2.50 ± 0.89 degree (group B) to 5.30 ± 1.04 degree (group E). Group A and B showed significantly less angular deviation than groups D and E (P < .05). There was no statistically significant differences in all parameters between group A and B, as well as between group D and E (P > .05). CONCLUSIONS: Significant differences were found with regards to accuracy among the five sCAIS systems tested, suggesting that the drilling protocol, the devices used and the design principles of the guides could influence the accuracy of implant placement.

The Stability of Augmented Bone Between Two Different Membranes Used for Guided Bone Regeneration Simultaneous with Dental Implant Placement in the Esthetic Zone.

PURPOSE: This randomized controlled clinical trial compared the stability of augmented bone between a synthetic resorbable membrane and a collagen resorbable membrane with guided bone regeneration (GBR) simultaneous with dental implant placement in the esthetic zone in terms of facial bone thickness. MATERIALS AND METHODS: A total of 60 dental implants from patients requiring implant placement with simultaneous GBR in the esthetic zone were equally allocated to the test group or control group by block randomization. Biphasic calcium phosphate ceramic bone was used in combination with either a polylactic acid (PLA) membrane (test group, 30 implants) or a resorbable collagen membrane (control group, 30 implants). Cone beam computed tomographic (CBCT) images were used to assess the facial bone thickness postimplantation and then 6 months later at four levels: implant platform and 2 mm, 4 mm, and 6 mm apical to the implant shoulder. RESULTS: All implants were osseointegrated, and no implant loss was found during this study. Facial bone was detected in all cases; however, the thickness of the facial bone was reduced at the 6-month follow-up in both groups. The percentage of facial bone thickness reduction was 34.30%, 27.94%, 24.25%, and 19.81% in the test group and 34.80%, 24.06%, 19.52%, and 20.45% in the control group at the level of the implant platform and at 2 mm, 4 mm, and 6 mm apical to the implant shoulder, respectively. Nevertheless, there was no statistically significant difference between the groups (P > .05). CONCLUSION: A synthetic resorbable membrane revealed an amount of stable augmented bone similar to that of a collagen resorbable membrane.