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Introduction: The human-derived amnion-chorion membrane (ACM) has endogenous antimicrobial properties, which are important for preventing the colonization and survival of oral bacteria on exposed membranes. This project aimed to decipher the underlying mechanism by identifying the components of ACM that confer antibacterial properties. In addition, the antimicrobial efficacy of these identified components on oral bacteria was assessed. Methods: Four antimicrobial proteins, histone H2A/H2B, cathelicidin LL-37, lactoferrin, and lysozyme, were identified via mass spectrometry in ACM. These proteins were then assessed for their efficacy in killing Streptococcus gordonii Challis. Log-phased bacterial cells were cultured with the commercially available proteins that were identified in ACM, either individually or in combination, at different concentrations. After incubation for 8 or 24 hours, the bacteria were stained with a live/dead viability kit and analyzed via confocal microscopy. Results: The combination of these proteins effectively killed S. gordonii in a dosedependent fashion after 8 or 24 hours of incubation. When each protein was tested individually, it killed S. gordonii at amuch lower efficacy relative to the combinations. The synergistic effects of the antimicrobial protein combinations were also observed in both the viable cell count recovery andminimum inhibitory concentration assays. Discussion: By shedding light on the mechanisms in the ACM's antimicrobial property, this study may raise more awareness of the potential benefit of utilization of a membrane with endogenous antimicrobial properties in regeneration surgeries. [ABSTRACT FROM AUTHOR]

(1) Background: OD burs are used in two different modes: (i) CW and (ii) CCW. The purpose of the study was to evaluate the ΔT during the preparation of implant osteotomies in a four-way interaction. (2) Methods: Three hundred and sixty osteotomies were prepared at 12 mm depth in human cadaver tibiae. The ΔT values were calculated similarly to the method used in two previous studies carried out by our group. Four different variables were evaluated for their effect on ΔT. (3) Results: A four-way interaction was observed in the CCW mode, allowing for 1000 RPM to have the least effect in both modes. However, in the CCW mode the use of 3.0 and 4.0 burs after 23 osteotomies showed a statistically significant increase in ΔT, and significant chatter, compared to the CW mode. In the CCW mode, the ΔT was increased significantly as the diameter of the burs increased in 800 and 1200 RPM. (4) Conclusions: The synergistic effect of drills' diameter, CCW mode, 800 and 1200 RPM, and bur usage (over 23 times) had a significant effect on ΔT, which exceeded 47 °C. One thousand (1000) RPM had the least effect in both modes. The 3.0 and 4.0 burs in the CCW mode drastically increased the temperature and produced significant chatter. [ABSTRACT FROM AUTHOR]

Periodontitis is a commonly occurring inflammatory oral disease affecting a large proportion of global and US adults and is characterized by the destruction of the tooth-supporting apparatus. Its etiology is multifactorial, and type 2 diabetes and diet play critical roles in its remission and progression. However, few studies have addressed nutritional and serum vitamin D status in adults with periodontitis in the presence of diabetes. A cross-sectional study (n = 78), and a sub-set of age- and BMI-matched case–control studies (n = 50), were conducted to examine differences in dietary and cardiometabolic variables, and serum vitamin D in adults with periodontitis with or without diabetes. Participants provided fasting blood samples and 24-h diet recalls on at least two different days. Data on health history, body weight, height, nutritional habits, and clinical features of periodontitis were also collected. The Mann–Whitney U Test (with exact p-value estimation by Monte Carlo simulation) was used to examine differences by diabetes status in continuous and ordinal variables. Results revealed significantly lower serum vitamin D, and dietary intake of fruits, vegetables, dairy, vitamins A and C in adults with periodontitis with vs. without diabetes in the sub-study (all p < 0.05). In the overall sample, adults with diabetes presented with higher caries risk measures and lower numbers of teeth than those without diabetes; plaque and bleeding scores did not differ by diabetes status. Finally, a significant associations of food habits was observed, especially consuming protein-rich foods twice a day with a lower bleeding score, and daily consumption of fried or fast foods with a fewer number of teeth present (all p < 0.05). The present findings show significant dietary and serum vitamin D inadequacies among adults with periodontitis, and diabetes further aggravates the observed malnourishment and oral health. [ABSTRACT FROM AUTHOR]

Objectives: Some commonly used models utilized for teaching periodontal surgical techniques to dental students include pig mandible and periodontal typodonts. Currently, no study compares the learning and teaching outcomes following the use of one model to the other. This study is aimed at evaluating the effectiveness of the preclinical laboratory component on student understanding of concepts taught in the periodontal surgical course and assessing students' and faculty members' satisfaction with the instructional models. Methods: As part of the surgical periodontics course, 98 students took the final exam, with eighty students participating in only the pig mandible session and twenty‐three students participating in both the pig jaw mandible and an additional session utilizing periodontal typodonts under the supervision of ten periodontal faculty members. Examination scores of students attending or not attending the laboratory session were analyzed by a two‐sample t‐test. A questionnaire evaluating the effectiveness of both models was given to faculty members and students who participated in both laboratory sessions. These results were analyzed by paired t‐test. Results: Participation in the laboratory sessions did not significantly impact the final exam scores (p = 0.722). Students who had better didactic performance in the course performed better in the final exam, irrespective of laboratory participation. Both students and faculty members preferred typodont to the pig mandibles in learning or teaching periodontal surgical concepts, but both felt gaining flap management and flap refection experience to be better with the pig mandible model without statistical significance (p = 0.119 and p = 0.070, respectively). Conclusion: Within the limitations of this study, we can conclude that laboratory sessions did not significantly improve student performance on the exam. Students and faculty members generally gave positive feedback on both instructional models. Periodontal typodont could be an alternative model for teaching dental students, periodontal surgical concepts. [ABSTRACT FROM AUTHOR]

Objective: The purpose of the present study was to present vertical ridge augmentation (VRA) with the use of cross-linked resorbable membrane, tenting screws, and a combination grafting technique. Report: Three cases are presented. Case 1: A 67-year-old ASA II patient required VRA at the areas of the mandibular left second premolar and first molar. Flap management was performed with the use of periosteal release on the buccal aspect and 23 mm of mylohyoid muscle release on the lingual aspect. VRA was completed with the use of four self-tapping tenting screws, and 1:1 mix of anorganic bovine bone matrix (ABBM) and particulate mineralized bone allograft. A cross-linked resorbable membrane was placed over the buccal and lingual aspect, and a double line of suturing was performed to secure the tension-free closure. Twelve months postoperatively, 4 mm of VRA was confirmed with CBCT. Two implants were placed with >35 Ncm primary stability. Case 2: A 64-year-old ASA I patient required VRA at the area of the maxillary first premolar. Flap management was performed with the use of periosteal release on the buccal aspect and VRA was performed with a 9-mm self-tapping screw, 1:1 mix of ABBM and particulate mineralized bone allograft, a cross-linked resorbable membrane, and a double line of suturing. Twelve months postoperatively, VRA of 6.2 mm on the buccal aspect and 7.9 mm on the lingual aspect were confirmed with CBCT. An implant was placed with >35 Ncm primary stability in combination with horizontal ridge augmentation. Case 3: A 70-yearold ASA II patient required horizontal and VRA at the area of the mandibular left canine. Following extraction, a lateral pedicle sliding flap was completed to enhance the soft tissue volume of the site. After 6 weeks, flap management was performed with the use of buccal periosteal release, VRA was completed with two self-tapping screws, 1:1 mix of ABBM and particulate mineralized bone allograft, a cross-linked resorbable membrane, and a double line of suturing. Eight months postoperatively there was 5.3 mm of bone regeneration on the vertical dimension and 3.9 mm on the horizontal dimension. An implant was placed with primary stability of 45 Ncm. Conclusion: Successful VRA can be achieved with proper flap management to achieve tension-free closure, a cross-linked collagen membrane, tenting screws, and a combination grafting technique. The VRA ranged from 4.0 to 7.9 mm. [ABSTRACT FROM AUTHOR]

Purpose: The rate of dental implant failures ranges from 3% to 8%, with that number increasing as the number of implants placed increases. When an implant fails, the survival rate drops significantly when a second or third attempt is performed. The aim of this study was to evaluate the survival rate of an implant placed in a previously failed implant site and to explore the risk factors that might affect the outcome of the second procedure. Materials and Methods: A retrospective chart review was conducted for patients receiving dental implants at the University of Texas, School of Dentistry from 1985 to 2017. Exclusion criteria included patients with genetic diseases, radiation and chemotherapy, or an age less than 18 years. Data on age, sex, race, tobacco use, diabetes, cardiovascular, osteoporosis, implant brand, anatomical location of the implant, implant length and width, respective information on the replacement implant, and professional maintenance were collected for analysis. Results: A total of 1,234 patients with 2,742 implants were included. A chart review found that of the 247 failed implants, replacement of implants was performed in 85 patients with 99 implants. More than half of the initial implants failed within the first year of placement. Based on the 12-month performance of each brand, the initially failed implants were categorized as high, medium, or low survival rates. Based on this categorization, the replacement implants that belonged to the medium survival rate category showed higher survival rates than the high survival group of the initially failed implants. Conclusion: The cumulative survival rates of the replacement implants were 91% at 1 year, 88% at 5 years, and 83% at 10 years. Implant failures were more common prior to functional loading. [ABSTRACT FROM AUTHOR]

(1) Background: Several studies showed a sustained temperature of 47 °C or 50 °C for one minute resulted in vascular stasis and bone resorption with only limited bone regrowth over a 3–4-week healing period. The purpose of the present study was to evaluate the temperature changes (ΔΤ) that occur during the preparation of dental implant osteotomies using MIS® straight drills versus Densah® burs in a clockwise (cutting) drilling protocol. (2) Methods: Two hundred forty (240) osteotomies of two different systems' drills were prepared at 6 mm depth at 800, 1000, and 1200 revolutions per minute (RPM), in fresh, unembalmed tibiae, obtained by a female cadaver. ΔΤ was calculated by subtracting the baseline temperature on the tibial surface, from the maximum temperature-inside the osteotomy (ΔT = Tmax − Tbase). The variables were evaluated both for their individual and for their synergistic effect on ΔΤ with the use of one-, two-, three- and four-way interactions; (3) Results: An independent and a three-way interaction (drill design, drill width, and RPM) was found in all three RPM for the Densah® burs and at 1000 RPM for the MIS® straight drills. As Densah® burs diameter increased, ΔΤ decreased. The aforementioned pattern was seen only at 1000 RPM for the MIS® straight drills. The usage of drills 20 times more than the implant manufacturers' recommendation did not significantly affect the ΔΤ. A stereoscopic examination of the specimens confirmed the findings. (4) Conclusions: The independent and synergistic effect of drills' diameter, design and RPM had a significant effect on ΔΤ in human tibiae, which never exceeded the critical threshold of 47 °C. [ABSTRACT FROM AUTHOR]

Introduction: Vertical ridge augmentation (VRA) is one of the most challenging procedures. This is the first case report to show 2–5 mm VRA after two unsuccessful GBRs around previously placed dental implants, with the use of an exposed d‐PTFE membrane. Case Presentation: A 79‐year‐old ASA II Caucasian male presented after two previous GBR procedures on the LLQ. The second attempt left the site with two exposed implants, scar tissue, no keratinized tissue and lack of vestibular depth. VRA was attempted with the use of cortical perforations, tenting screws, dense PTFE membrane and a 50:50 mixture of anorganic bovine bone matrix and mineralized allograft. The site was left to heal in a secondary intention, leaving the d‐PTFE membrane exposed. The membrane was removed 4 weeks postoperatively. The healing abutments were placed, the tenting screws were removed, and the site was allowed to heal for more than seven months. Radiographically, VRA was achieved ranging from 2 to 5 mm. A vestibuloplasty was performed using a diode laser and subsequent flap dissection. Four months after the vestibuloplasty, the tissue surrounding the implants showed adequate keratinization, and an elongated vestibular depth. In addition, in both implants, the emergence profile buccal and lingual was more than 3 mm and the patient was referred to his prosthodontist for the fabrication of the final restorations. Conclusions: VRA around dental implants was achieved with the use of a nonresorbable dense PTFE membrane, which was left exposed to heal in a secondary intention, tenting screws and a combination grafting technique to correct two previously failed GBRs. [ABSTRACT FROM AUTHOR]

Objective: The objective of this cross‐sectional study is to investigate alveolar bone gene expression in health and diabetes through ribonucleic acid (RNA) sequencing and bioinformatics analysis. Background: It is relatively unknown how type 2 diabetes modulates gene expression in alveolar bone in humans. Clinical concern regarding increased implant failure rate in patients with diabetes has been discussed in the literature. Previous studies in animal models and humans have suggested an imbalance between the genes regulating bone formation with data suggesting bone resorption in diabetes. However, there is lack of data regarding a comprehensive gene expression from human alveolar bone in diabetes. Methods: Alveolar bone was collected from healthy and type 2 diabetic subjects undergoing periodontal and implant surgeries. The homogenized RNA sample was then extracted and analyzed for quantity and quality. RNA samples were further purified using ribosomal RNA depletion technique and processed for RNA sequencing and analysis. Expression levels for mRNAs were performed by calculating FPKM ([total_exon_fragments/mapped reads (millions) × exon length (kB)]), and differentially expressed mRNAs were selected with log2 (fold change) >1 or log2 (fold change) ≤1 and with a parametric F test comparing nested linear models. Results: Eighteen bone samples (10 healthy, 8 patients with diabetes) were analyzed for gene expression. The mean age and HbA1c% of healthy versus diabetic subjects were as follows: age (55.3 ± 17.5 vs 63.9 ± 8.7 years) and HbA1c% (5.6 ± 0.29 vs 7.3 ± 2.4), respectively. Sequencing analysis showed that expression of genes that regulate bone turnover like TGFB1, LTBP4, IGF1, BMP2, BMP4, BMP6, SMAD1, RUNX2, MCSF, and THRA was significantly downregulated in diabetes samples compared with healthy controls with overall reduced expression of genes in the bone regulation pathway in patients with diabetes. Bioinformatics analysis for the altered genes highlighted several pathways related to bone homeostasis and inflammation in diabetes. Periodontitis did not affect the gene expression pattern based on diabetes status. Conclusions: Altered expression of genes due to downregulation of certain pathways that are involved in bone turnover and inflammation suggests that overall wound healing and bone homeostasis may be compromised in type 2 diabetes. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this retrospective chart-review study was to compare the early success rate and the crestal bone changes of dental implants in patients taking oral bisphosphonates at the time of implant placement to those of patients who had never taken bisphosphonates. Materials and Methods: A retrospective chart review of 100 women (153 implants) taking oral bisphosphonates at the time of implant placement (test group) and 100 women (132 implants) who had never taken bisphosphonates (control group) was performed to examine overall implant success at the time of stage-two surgery. Radiographic images, which were available for 73 patients in each group and were taken at the time of implant placement and at stage-two surgery, were analyzed to assess and compare crestal bone changes around the implants. Results: There was no significant difference between groups in the success rates of dental implants at stage-two surgery (test 93.5%, control 95.5%). The change in crestal bone height was statistically significant from the time of placement to stage-two surgery within both groups but was not significantly different between groups (means ± standard deviations: test, 0.66 ± 0.70 mm; control: 0.80 ± 0.65 mm). Conclusions: In this study, the use of oral bisphosphonates at the time of implant placement and during healing did not affect early implant success rates or crestal bone changes up to the time of stage-two surgery. In addition, the implant location and the duration of drug therapy at the time of placement were not significant factors in the success rate or bony changes. These conclusions must be viewed in the context of the limitations of the retrospective study design and should be confirmed in longer, more rigorously designed studies. [ABSTRACT FROM AUTHOR]

Background: Implants have been widely used to restore missing teeth. Limited information on applied anatomy at the anterior maxilla compromises the clinical outcome for implant placement in this region. In the current study, Cone Beam Computerized Tomography (CBCT) was used to measure alveolar ridge and buccal undercut dimension at the anterior maxilla to help develop treatment planning for immediate implant placement. Methods: CBCT scans were screened to include 51 subjects with full dentition at right maxilla. Measurements were taken at the cross sectional views in the middle of the maxillary right central incisor, lateral incisor, and canine regions. Alveolar height was measured from the alveolar crest to floor of nasal fossa. Alveolar width was measured from the buccal to palatal cortical plate at the coronal, middle, and apical third of the distance from the alveolar crest to floor of the nasal fossa. Buccal undercut location was measured from where the buccal cortical plate started dipping to a line extending at the alveolar crest that was perpendicular to the long axis of the alveolar ridge. The buccal undercut depth was measured from the deepest point of the undercut at the buccal plate to a line tangent to the buccal plate paralleling the long axis of ridge. Results: Alveolar width increased from coronal to apical direction for each tooth. Mean alveolar widths (mm) were: central incisor, 9.55; lateral incisor, 8.30; canine, 9.62. The lateral incisor had a significantly smaller alveolar width than the other anterior teeth. No significant difference in ridge height was noted among the teeth. Undercut locations from the alveolar crest (mm) were: central incisor, 5.84; lateral incisor, 3.59; canine, 5.11. Undercut depths (mm) were: central incisor, 0.76; lateral incisor, 0.87; canine, 0.73. The percentages of teeth with buccal undercuts were: central incisor, 41 %, lateral incisor, 77 %, and canine 33 %. Male demonstrate significant larger ridge width compared with females for all three teeth. Conclusions: At anterior maxilla, the lateral incisor has the thinnest alveolar bone, and most frequently exhibits a buccal undercut which is the closest to alveolar ridge compared with other maxillary anterior teeth. [ABSTRACT FROM AUTHOR]

Objective Studies demonstrated immediate implant sites commonly have ridge dimensional alterations accompanied with post-op mucosal recession that compromise esthetic outcomes. The use of an autogenous tissue graft or an acellular dermal matrix was proposed to compensate these changes. However, the results of studies were equivocal. This randomized controlled trial was aimed to evaluate the impact of immediate implant combined with soft tissue augmentation on preserving tissue contour. Methods This study had three groups: immediate implant (IM), immediate implant combined with the subepithelial connective tissue graft (IMCT), and immediate implant combined with the acellular dermal matrix (IMAD). The included patients had a single unrestorable tooth in the esthetic zone (maxillary incisors, canines and premolars) with adjacent teeth. The surgical sites should have acceptable buccal gingival level, interproximal bone level (recession or bone loss< 2mm) and mostly intact buccal plate. All implants were immediately placed following extraction and xenografts were placed to fill in any bony defects. Each implant was randomly assigned to one group (the size of the graft was standardized). A healing abutment was placed and allowed to heal for six months before the permanent crown delivery (Figure 1). Smokers (<10 cigarettes per day) were included. The primary outcome was ridge dimensional alteration while the secondary outcomes were changes of peri-implant mucosal level, mucosal thickness, bone level and bone dimension. Based on the power calculation, 15 patients in each group was planned to be recruited. Ridge dimensional changes were measured by computerassisted scanned images of dental models. The images of periapical radiographs and cone beam computed tomography were used to measure bone levels and dimensions. All clinical measurements were performed by a single examiner using a stent with reference marks at four visits (baseline, 3, 6, 12 months following the surgery) (Figures 2, 3, 4). Results To date, fifteen patients completed the 12-month visit and nineteen patients completed the 6-month visit. Only 6-month results of these nineteen patients (n=9, 6, 4 in the IM, IMCT, and IMAD groups) were reported (Table 1). The reduction of buccal horizontal ridge dimension (BHRD) or buccal horizontal bone dimension (BHBD) did not seem to be different between groups (mean BHRD: 0.65±0.66, 0.47±0.95, 0.12±1.16mm; mean BHBD: 0.42±1.21, 0.05±1.69, 0.78±0.71mm in the IM, IMCT, and IMAD respectively). The mean changes of peri-implant mucosal levels were within 1mm (mean mid-buccal mucosal recession: -0.33±1.03, 0.50±0.77, 0.16±1.55 mm; mean mesiobuccal mucosal recession: 0.61±0.65, 0.33±0.52, 0.75±0.65mm; mean distobuccal mucosal recession: 0.44±0.81, 0.33±0.61, 0.63±1.60mm in IM, IMCT and IMAD respectively). Soft tissue augmentation appeared to increase peri-implant mucosal thickness (mean mucosal thickness gain: 0.18±0.15, 0.78±0.34, 1.27±0.83mm in IM, IMCT and IMAD respectively). Radiographic alveolar bone levels appeared to be stable (mean marginal bone loss at the mesial site:0.99±1.34, 0.07±0.16, 0.75±1.07mm; at the distal site: 0.73±1.15, 0.02±0.04, 1.23±1.13mm in the IM, IMCT and IMAD respectively). No further statistical analysis was performed since the study was not finished. Conclusions The preliminary results demonstrated soft tissue augmentation increased tissue thickness but did not appear to have significant impact on preserving peri-implant mucosal level, bone level, bone dimension and ridge dimension. No conclusive statement could be made until the study is finished. [ABSTRACT FROM AUTHOR]

Introduction: The human-derived amnion-chorion membrane (ACM) has endogenous antimicrobial properties, which are important for preventing the colonization and survival of oral bacteria on exposed membranes. This project aimed to decipher the underlying mechanism by identifying the components of ACM that confer antibacterial properties. In addition, the antimicrobial efficacy of these identified components on oral bacteria was assessed., Methods: Four antimicrobial proteins, histone H2A/H2B, cathelicidin LL-37, lactoferrin, and lysozyme, were identified via mass spectrometry in ACM. These proteins were then assessed for their efficacy in killing Streptococcus gordonii Challis. Log-phased bacterial cells were cultured with the commercially available proteins that were identified in ACM, either individually or in combination, at different concentrations. After incubation for 8 or 24 hours, the bacteria were stained with a live/dead viability kit and analyzed via confocal microscopy., Results: The combination of these proteins effectively killed S. gordonii in a dose-dependent fashion after 8 or 24 hours of incubation. When each protein was tested individually, it killed S. gordonii at a much lower efficacy relative to the combinations. The synergistic effects of the antimicrobial protein combinations were also observed in both the viable cell count recovery and minimum inhibitory concentration assays., Discussion: By shedding light on the mechanisms in the ACM's antimicrobial property, this study may raise more awareness of the potential benefit of utilization of a membrane with endogenous antimicrobial properties in regeneration surgeries., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Brummerhop, Lee, Weltman, Tribble, van der Hoeven, Chiu, Hong and Wang.)

Periodontitis is a commonly occurring inflammatory oral disease affecting a large proportion of global and US adults and is characterized by the destruction of the tooth-supporting apparatus. Its etiology is multifactorial, and type 2 diabetes and diet play critical roles in its remission and progression. However, few studies have addressed nutritional and serum vitamin D status in adults with periodontitis in the presence of diabetes. A cross-sectional study ( n = 78), and a sub-set of age- and BMI-matched case-control studies ( n = 50), were conducted to examine differences in dietary and cardiometabolic variables, and serum vitamin D in adults with periodontitis with or without diabetes. Participants provided fasting blood samples and 24-h diet recalls on at least two different days. Data on health history, body weight, height, nutritional habits, and clinical features of periodontitis were also collected. The Mann-Whitney U Test (with exact p -value estimation by Monte Carlo simulation) was used to examine differences by diabetes status in continuous and ordinal variables. Results revealed significantly lower serum vitamin D, and dietary intake of fruits, vegetables, dairy, vitamins A and C in adults with periodontitis with vs. without diabetes in the sub-study (all p < 0.05). In the overall sample, adults with diabetes presented with higher caries risk measures and lower numbers of teeth than those without diabetes; plaque and bleeding scores did not differ by diabetes status. Finally, a significant associations of food habits was observed, especially consuming protein-rich foods twice a day with a lower bleeding score, and daily consumption of fried or fast foods with a fewer number of teeth present (all p < 0.05). The present findings show significant dietary and serum vitamin D inadequacies among adults with periodontitis, and diabetes further aggravates the observed malnourishment and oral health.