Influences of race/ethnicity in periodontal treatment response and bacterial distribution, a cohort pilot study.

Objectives: Periodontitis disproportionately affects different racial and ethnic populations. We have previously reported the higher levels of Porphyromonas gingivalis and lower ratios of Streptococcus cristatus to P. gingivalis may contribute to periodontal health disparities. This prospective cohort study was designed to investigate if ethnic/racial groups responded differently to non-surgical periodontal treatment and if the treatment outcomes correlated to the bacterial distribution in patients with periodontitis before treatment. Methods: This prospective cohort pilot study was carried out in an academic setting, at the School of Dentistry, University of Texas Health Science Center at Houston. Dental plaque was collected from a total of 75 African Americans, Caucasians and Hispanics periodontitis patients in a 3-year period. Quantitation of P. gingivalis and S. cristatus was carried out using qPCR. Clinical parameters including probing depths and clinical attachment levels were determined before and after nonsurgical treatment. Data were analyzed using one-way ANOVA, the Kruskal-Wallis test, the paired samples t-test and the chi-square test. Results: The gains in clinical attachment levels after treatment significantly differed amongst the 3 groups-Caucasians responded most favorably, followed by African-Americans, lastly Hispanics, while numbers of P. gingivalis were highest in Hispanics, followed by African-Americans, and lowest in Caucasians (p = 0.015). However, no statistical differences were found in the numbers of S. cristatus amongst the 3 groups. Conclusion: Differential response to nonsurgical periodontal treatment and distribution of P. gingivalis are present in different ethnic/racial groups with periodontitis.

The Associations of Cardiometabolic and Dietary Variables with Clinical Periodontitis in Adults with and without Type 2 Diabetes: A Cross-Sectional Study.

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.

The ability to screw-retain single implant-supported restorations in the anterior maxilla: A CBCT analysis.

STATEMENT OF PROBLEM: Evidence to validate the routine use of angled screw-channel abutments in the anterior maxilla is sparse. If properly planned, they might provide surgical and prosthetic benefits. PURPOSE: The purpose of this observational study was to determine the prevalence of digitally placed implants in the anterior maxilla that would allow screw-retained implant-supported restorations with either a straight or an angled screw-channel abutment. MATERIAL AND METHODS: Two hundred cone beam computed tomography (CBCT) scans met the inclusion criteria for retrospective analysis and digital implant planning. Virtual implants were planned for randomly selected anterior maxillary teeth by using the anatomic crown and root position. Virtual abutments of varying angulation were attached to the implants to determine the ability to screw retain a restoration with either a straight or an angled screw-channel abutment. RESULTS: One hundred fifty-two (76%) sites required an angled screw-channel abutment to enable screw retention. Forty-eight (24%) sites allowed screw retention with a straight abutment. The percentage of implants requiring angled or straight abutments varied significantly among anterior teeth (P<.005). One hundred nine (71.7%) angled screw-channel abutment sites required a 5-degree abutment, 41 (26.9%) required a 10-degree abutment, and 2 (1.3%) required a 15-degree abutment. Among the anterior teeth, lateral incisors presented a greater need for angled screw-channel abutments. None of the implants in the present study needed cement-retained restorations. CONCLUSIONS: Angled abutments allowed for screw-retained restorations on digitally planned implants in the anterior maxilla. The required angular correction to a screw-retained restoration was ≤15 degrees. Screw-retained restorations were frequently achievable (76%) with the use of angled screw-channel abutments or with straight abutments (24%), and lateral incisors presented a greater need for angled screw-channel abutments.

Altered human alveolar bone gene expression in type 2 diabetes-A cross-sectional study.

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.

Antimicrobial Efficacy Assessment of Human Derived Composite Amnion-Chorion Membrane.

Human derived composite amnion-chorion membrane (ACM) has been used to facilitate wound healing due to reported anti-inflammatory properties and promotion of cell proliferation. This study aimed to assess the antimicrobial properties of the ACM using novel methods to visualize the antimicrobial efficacy of membranes in situ at different time points. Porcine Pericardium Collagen Membranes (PPCM) served as membrane controls. Circular pieces of the membranes were used in three different assays: insert, agar contact and glass-bottom well assays. Streptococcus gordonii were spotted onto the membranes and the plates were subsequently centrifuged to ensure direct bacterial contact with the membranes in the insert and agar contact assays, thus better mimicking bacterial adherence in the oral cavity. After incubation at 37 °C for 8, 24, and 48 hours, the membranes were dyed with the Live/Dead BacLight Bacterial Viability fluorescence stain and analyzed via confocal microscopy. The results demonstrated that the ACM completely inhibited bacterial growth at all time points, whereas the PPCM did not demonstrate any antimicrobial properties. Within the limits of this study, the ACM showed extremely high antimicrobial efficacy against oral streptococci. In addition, our methods may be useful in assessing antimicrobial properties for biomaterials with minimum diffusion ability, when traditional assessment methods are not applicable.

Oral bisphosphonates: early endosseous dental implant success and crestal bone changes. A retrospective study.

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.

Ridge preservation with or without an osteoinductive allograft: a clinical, radiographic, micro-computed tomography, and histologic study evaluating dimensional changes and new bone formation of the alveolar ridge.

BACKGROUND: The aim of this randomized, controlled clinical trial is to determine whether ridge preservation using an osteoinductive allograft (test) would prevent ridge resorption and promote bone maturation compared to extraction alone (control). METHODS: Seventeen patients (20 total sites), in need of a non-molar extraction and delayed implant placement were randomly selected to receive either ridge preservation or extraction alone. A cone-beam computed tomography was completed with a radiographic stent in place before extraction and 10 to 12 weeks postoperatively for dimensional and buccal plate analyses. Bone cores were taken for micro-computed tomography (microCT) and histologic analyses. RESULTS: Resorption of the alveolar ridge occurred at all sites with no statistically significant differences found between test and control sites. A significant correlation was found between the initial buccal plate thickness and the loss of vertical ridge height. microCT and histologic analyses found a mean new bone volume of 44.9% with microCT and 37.4% with histology in test sites and 39% and 35.5%, respectively, in control sites. The residual graft volume was 2.4% with microCT and 4.5% with histology. CONCLUSIONS: Test and control sites lost similar amounts of alveolar ridge, with the loss of buccolingual width occurring predominantly at the expense of the buccal bone. A thicker buccal plate was associated with less ridge loss in the vertical dimension. The percentage of new bone was not statistically significant between either the test or control sites, using either microCT or histologic analyses.

Regeneration of degree ii furcation defects with a 4% doxycycline hyclate bioabsorbable barrier.

BACKGROUND: Bacterial contamination of a healing regenerative site has been shown to affect the response to therapy adversely. Doxycycline possesses antibacterial properties as well as other biologic actions that may result in an increased production and maintenance of collagen and bone. The purpose of this study was to assess if the sustained release of 4% doxycycline through a bioabsorbable barrier would enhance the regenerative outcomes of healing furcation sites. METHODS: Individuals with a single degree II furcation defect in a mandibular molar participated. They were assigned randomly to one of three treatment groups: poly(DL-lactide) polylactic acid (PLA) barrier containing 4% doxycycline hyclate + demineralized freeze-dried bone allograft (DFDBA) (BG+PDox); poly(DL-lactide) PLA barrier without doxycycline + DFDBA (BG+P); or DFDBA alone (BG). Clinical parameters included vertical probing depth (VPD), vertical clinical attachment level (VCAL), gingival recession, and horizontal probing depth (HPD). Intrasurgical measurements to calculate vertical and horizontal furcation fill were obtained at the time of surgery (baseline) and during a reentry procedure 9 months later. Statistical tests were used to assess changes in the clinical and surgical parameters before and after treatment among groups and within each group. RESULTS: Mean changes at 9 months for all groups yielded VPD reductions and VCAL gains. However, no significant difference was noted for the group that was treated with 4% doxycycline barrier compared to the other two groups. Vertical bone fill was 0.89, 1.44, and 1.18 mm for the BG+PDox, BG+P, and BG groups, respectively. Furcation horizontal bone was 2.33, 2.11, and 1.18 mm for the BG+PDox, BG+P, and BG groups, respectively. CONCLUSIONS: Addition of doxycycline to the guided tissue regeneration barrier did not enhance treatment outcomes compared to the non-antibiotic-loaded barrier or bone graft alone. All treatment modalities provided similar improvement in clinical and intrasurgical parameters.

Treatment of intrabony defects with bovine-derived xenograft alone and in combination with platelet-rich plasma: a randomized clinical trial.

BACKGROUND: In the treatment of periodontal intrabony defects, the benefits of adding platelet-rich plasma (PRP) to a bone replacement grafting material have not been tested. The purpose of this study was to compare the clinical outcomes obtained by the combination of PRP and a bovine derived xenograft (BDX) to those obtained from the use of the bone replacement graft alone. METHODS: Thirteen patients were enrolled in a randomized, split mouth, double-masked clinical trial. Bilateral defects were matched according to their intrasurgical measurements. Qualifying defects had loss of attachment of > or = 6 mm, a radiographically detectable defect of > or = 4 mm, at least two remaining osseous walls, and not primarily related to a furcation involvement. After the hygienic phase, at the baseline examination, probing depth (PD), clinical attachment level (CAL), and recession (REC) were measured. During open flap debridement, the defects were randomly assigned to receive either BDX mixed with PRP or BDX alone. Baseline osseous intrasurgical measurements were obtained. Post-surgical follow-up and maintenance were performed and PD, CAL, and REC were remeasured at 6 months. The mean baseline and 6-month PD, CAL, and REC of the deepest buccal and lingual measurements related to the defect for each group were computed. The change from baseline to 6 months for each parameter measured was calculated. Pre- and postoperative comparisons were made between treatment groups at 6 months. RESULTS: Randomization of the defects resulted in comparable groups (P > or = 0.05). At 6 months, paired t test comparisons within groups showed statistically significant benefits with both treatment modalities (P < or = 0.05). The mean changes (delta) at 6 months for the test and the control groups at the deepest sites were: PD reduction: 3.54 and 2.53 mm; CAL gain: 3.15 and 2.31 mm; and REC: -0.38 and -0.23 mm, respectively. Paired t test comparisons yielded significant differences between treatments for PD and CAL (P < or = 0.05). CONCLUSION: In this 6-month clinical trial, the addition of a high concentration of autologous platelets to a bovine derived xenograft to treat intrabony defects significantly improved their clinical periodontal response.

Favorable periodontal regenerative outcomes from teeth with presurgical mobility: a retrospective study.

BACKGROUND: The relevance of tooth mobility on periodontal healing is still controversial. The purpose of the present study was to evaluate the effect of presurgical tooth mobility on periodontal regenerative outcomes. METHODS: The data in this study were derived from three randomized clinical trials which evaluated regenerative procedures. Sixty-four patients with one intraosseous periodontal defect each received one of the following treatments: guided tissue regeneration (GTR) using expanded polytetrafluoroethylene (ePTFE), GTR using a bioabsorbable membrane with or without demineralized freeze-dried bone allograft (DFDBA), or enamel matrix derivative with or without DFDBA. Probing depth (PD), clinical attachment level (CAL), recession (REC), and tooth mobility (TM) were recorded at baseline and 1 year after treatment by a calibrated examiner. The post-surgical follow-up and maintenance periods were designed to optimize plaque control. The teeth were grouped according to their baseline Miller index TM score. The grouping yielded 36 teeth with minimal mobility, score 0; 13 teeth with score 1; and 15 with score 2. The mean changes in PD, CAL and REC from baseline to 1 year were calculated for each group. One-way analysis of variance (ANOVA) was performed to assess differences between the tooth mobility groups considering changes in PD, CAL, and REC at 1 year. RESULTS: The mean PD reduction from baseline to 1 year for teeth with TM score 0 was 3.67 mm; for TM score 1, 2.81 mm; and for score 2, 3.73 mm. The corresponding values for the gain in CAL were 2.73, 1.96, and 2.36 mm, respectively. According to ANOVA, the probing depth reductions and clinical attachment level gains found in each group were not statistically different, P= 0.218 and P= 0.252, respectively. CONCLUSION: Within the limitations of this analysis, it can be concluded that interproximal, intraosseous defects of teeth with limited presurgical tooth mobility; i.e., teeth with Miller's Class 1 and 2 mobility, will respond favorably to regenerative therapy.