Comparing Bone Graft Success, Implant Survival Rate, and Marginal Bone Loss: A Retrospective Study on Materials and Influential Factors.

This retrospective study aimed to evaluate success rate of guided bone regeneration (GBR) bone grafting and investigate survival rate of implants, as well as degree of marginal bone loss (MBL) around implants. This study was carried out between January 2007 and December 2016 on treatment outcomes of patients with implants which used various graft materials, including autograft, allograft, and xenograft. The bone graft success rate and implant survival rate were recorded. The influence of confounding factors such as patient characteristics, bone graft properties, and implant conditions was considered. Moreover, MBL up to 3 years after implant installation was evaluated in periapical radiographs. In mean follow-up 70 months (range 3-10 years), overall success rate of bone graft (n=80) was 100% and overall survival rate of implant (n=107) was 97.2% (autograft and allograft 100%, and xenograft 92.9%, respectively; P=.03). The 3-year MBL were similar among bone grafts (autograft 0.84±0.48mm, allograft 0.73±0.42mm and xenograft 1.01±0.59mm, respectively; P=.14). Posterior mandibular location had a significant influence on implant survival (P=.003). Regarding MBL, patients aged >60 years (P=.03), patients with both diabetes and hypertension (P=.02), patients who did not receive adjunctive membrane use (P=.04), patients with <6 months of loading (P<.001) and patients with screw-retained crowns (P=.008) were significantly associated. Our data substantiated that implant rehabilitation with GBR using autograft and allograft provide the most predictable results. With xenograft, aforementioned factors should be carefully considered to enhance long-term clinical outcomes.

Reproducibility of Computerized Cephalometric Analysis Software Compared with Conventional Manual Tracing for Analyzing Skeletal Stability After Orthognathic Surgery.

Objective: This study aimed to compare the difference between analyzing skeletal stability after orthognathic surgery by lateral cephalogram measurement created from Dolphin software (version 11.95) compared with the manual technique. Methods: Twenty-eight patients who underwent mandibular setback surgery (BSSRO) were randomly selected between 2015 and 2021. Serial lateral cephalograms were analyzed at four different time sets postoperatively, and a total of 112 cephalometric radiographs were obtained. Horizontal measurement (BX), vertical measurement (BY), and 3 angular measurements (SNB, ANB, and Gonial angle) were analyzed by manual tracing and Dolphin software by 2 examiners. The intraclass correlation coefficient determined the intra-rater reliability. Parameter differences between timelines were observed for skeletal stability, and mean values between methods were compared using the Student's t-test. Results: Both examiners were generally consistent in the repeated measurements (ICCs of the manual method ranged from 0.926 to 0.994, and the digital method ranged from 0.719 to 0.956). All variables represented skeletal stability at T0-T1, T0-T2, and T0-T3 showed no statistically significant differences between methods except ANB (T0-T1; p value = 0.009). Conclusions: Computerized cephalometric analysis software is relatively reproducible for assessing skeletal changes after orthognathic surgery and can be used routinely in follow-up.

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.

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.

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.

Factors affecting the reduction rate of odontogenic cysts after decompression based on 3-dimensional volumetric analysis.

Purpose: This study aimed to investigate the potential factors that could affect the reduction rate of odontogenic cysts following decompression using cone-beam computed tomography (CBCT) for 3-dimensional volumetric analysis. Materials and Methods: The study sample consisted of CBCT images of 41 individuals who underwent decompression of odontogenic cysts at the Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Chulalongkorn University, between 2010 and 2022. Preoperative and postoperative CBCT results were collected, and a volumetric analysis was conducted to evaluate the differences in the reduction rate and the percentage of volume reduction of cystic lesions based on different parameters. Correlations between these parameters were analyzed to determine associations. Results: In this study, the average time of decompression for odontogenic cysts was 316 days. Males demonstrated a higher reduction rate than females (P<0.05). The reduction rate was directly proportional to initial cyst volume, with higher reduction rates for cysts with large initial volume than those with small initial volume (P<0.05). Spearman's rank correlation coefficient indicated a weak positive correlation between the initial cyst volume and the duration of decompression. Additionally, a strong positive correlation was observed between the initial volume and the reduction rate. Conclusion: Knowledge of the reduction rate of odontogenic cysts is vital for surgeons to evaluate the duration of decompression before enucleation and to determine a definitive treatment plan. Sex and initial lesion volume had significant effects on the reduction rate.

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.

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.

Complications related to orthognathic surgery: A 10-year experience in oral and maxillofacial training center.

This article aimed to review adverse events and complications to orthognathic surgery based upon 10 years. This study was a retrospective investigation between 2009 and 2018. Independent variables such as sex, age, pre-operative conditions, diagnosis, type of surgery, bleeding volume, surgery duration, and hospitalization were recorded. The data regarding orthognathic surgery adverse events and complications were evaluated and statistically analyzed with a significance level of p < 0.05. A total of 891 patients were included in this study (male 39.1%, female 60.9%) with a mean age of 26.4 ± 6.09 years. A neurosensory disturbance was found as immediate post-operative sequelae as 93.5%. The four most frequent complications had a relapse (6.4%), post-operative TMD (5.7%), unfavorable osteotomy (5.5%), and infection (4.9%), which seem to be more common in males. An average blood loss was 497 ± 371 ml and the average operative time was 401 ± 109.3 min. Complication rates were statistically affected by bleeding volume (p-value = 0.01), operative time (p-value = 0.03), and type of skeletal deformity (p-value = 0.01). Although numerous complications were recorded, no fatal complications were experienced. Bleeding time, operative time, and skeletal classification have significant influence on orthognathic surgery complications. However, a multitude of factors could be modified to reduce the complication rate and improve the result of the treatment. One of the most significant factors was the operative time.

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.

Drinking green tea alleviates alveolar bone resorption in ligature-induced periodontitis in mice.

OBJECTIVES: It has been reported that green tea exerts antibacterial, anti-inflammatory, and antioxidant effects. The purpose of the present study was to evaluate the effects of drinking green tea on bone resorption in ligature-induced periodontitis in mice. METHODS: Sixty C57BL/6 eight-week-old male mice were used. To induce periodontitis, a ligature was placed for 7 days around the upper left second maxillary molar. After ligature removal, the animals were administered different concentrations of green tea (1.5 g/60 mL, 3 g/60 mL, or 6 g/60 mL) or distilled water. At 1 and 2 weeks of administration, the animals were sacrificed and micro-CT images of the maxillae were taken. Next, the depth and area of alveolar bone loss in the buccal and palatal sides were measured. The number of inflammatory cells and osteoclasts in histological sections were counted. RESULTS: The result showed ligature-induced alveolar bone loss. Green tea inhibited ligature-induced bone loss in the buccal side in a dose-dependent manner. Histologically, ligature increased the number of inflammatory cells and osteoclasts, but this effect was alleviated by green tea. CONCLUSIONS: Evidence from this animal experiment suggested that drinking green tea would be potentially beneficial to reduce alveolar bone loss in ligature-induced periodontitis.

Ligature induced peri-implantitis: tissue destruction and inflammatory progression in a murine model.

OBJECTIVES: The aim of this study was to investigate tissue destruction and inflammatory progression of ligature-induced peri-implantitis in mice and to establish an alternative murine model of peri-implantitis. MATERIAL AND METHODS: Sixty male C57BL/6NCrSlc mice (4-week-old) were used and the maxillary right first molars were extracted. Eight weeks after extraction, custom-made pure titanium machined screw type implants (0.8 × 1.5 mm) were placed, one implant per animal. Four weeks later, 5-0 silk ligatures were applied around implant necks to induce peri-implantitis. Animals were sacrificed at 0 (before ligature), 7, 14, 21 and 28 days after ligature. Half of the samples were analyzed radiologically and histologically to measure bone level change, osteoclast number, density, and distribution. The rest of the samples was used to determine the relative mRNA expression levels of IL-1 and TNF-α with RT-PCR analysis. RESULTS: Bone levels at all sites (buccal, palatal, mesial, distal) decreased 40-50% significantly 28 days after ligature (P < 0.01). Osteoclast number at all post-ligature time points increased significantly (P < 0.05). However, their density at day 28 decreased significantly compared to that of day 21 (P < 0.05). Accordingly, IL-1 and TNF-α mRNA expression increased significantly at the early time points but decreased significantly at day 28 after ligature (P < 0.05). CONCLUSIONS: Inflammatory response followed by significant peri-implant bone resorption suggested 28 days ligation is sufficient to successfully induce peri-implantitis in the current mice model. This model might open a new avenue to study the pathogenesis and mechanism of peri-implantitis.