Interproximal contact loss between implant-supported restorations and adjacent natural teeth: A retrospective cross-sectional study of 83 restorations with an up to 10-year follow-up.

STATEMENT OF PROBLEM: Interproximal contact loss between implant-supported restorations and adjacent natural teeth is a frequently encountered complication that could negatively affect surrounding tissues and/or patient satisfaction with treatment. The effect of interproximal contact loss on peri-implant tissue health and patient awareness of food impaction is currently unknown. PURPOSE: The purpose of this retrospective cross-sectional study was to explore the effect of interproximal contact loss on peri-implant tissue health and determine whether interproximal contact loss leads to increased patient awareness of food impaction around the affected area. This study also aimed to identify whether specific patient or local factors could cause interproximal contact loss. MATERIAL AND METHODS: Eighty-three participants with posterior single-unit implant-supported restorations were examined. The mean follow-up time after prosthesis insertion was 4 ±2.2 years (range 4 months to 10.6 years). Interproximal contacts were evaluated by using waxed dental floss. Patient age, sex, implant location, opposing tooth status, presence of endodontically treated adjacent tooth, and regular use of an occlusal device at night were recorded. Peri-implant probing depths and the presence of bleeding on probing were also recorded. Each participant was asked to indicate whether they had noticed increased food impaction around their implant-supported restoration. Statistical analysis included nonparametric Mann-Whitney U tests, the Spearman rank-order correlation, the Pearson chi-squared tests, and the paired t test (α=.05). RESULTS: Among all examined mesial contacts, 34.1% were recorded as open, with an overall mesial interproximal contact loss (open and loose contacts combined) incidence of 48.8%. Restorations placed in premolar sites exhibited significantly tighter mesial interproximal contacts compared with those placed in molar sites (U=566, P=.041). A significant negative correlation was found between follow-up time after insertion and mesial contact tightness (rs=-0.226, P=.041). CONCLUSIONS: Interproximal contact loss appears to increase over time, with more surfaces being affected after longer periods of service. This study did not find an association between interproximal contact loss and peri-implant inflammation as measured by bleeding on probing, with the exception of the distolingual implant surface. Participants with interproximal contact loss were more aware of food impaction around their implant crown. Use of an occlusal device at night did not prevent interproximal contact loss.

Clinical and Patient-Reported Outcomes of Single Posterior Implant-Supported Restorations Completed by Predoctoral Students: A Retrospective Study with Up to 10 Years of Follow Up.

PURPOSE: To assess clinical outcomes of screw-retained implant-supported restorations as well as patient satisfaction and Oral Health-related Quality of Life (OHQoL), when treatment is performed in an academic setting by supervised predoctoral students. MATERIALS AND METHODS: Ninety patients (n = 129 restorations) consented to participate in the study. The mean follow-up period was 4.2 years (range: 4 months to 10.6 years) after crown insertion. All patients filled out a modified Oral Health Impact Profile questionnaire, consisting of 14 questions (OHIP-14). A comprehensive examination of the implant-supported restoration was completed and restorative complications were recorded. Statistical analysis was performed using SPSS (IBM SPSS Statistics, v25; IBM Corp). Restoration survival rates were calculated using Kaplan-Meier survival analysis. RESULTS: The most frequent complication was loss of the mesial interproximal contact (32.2%). The overall restoration survival and success rates were 93.8% and 74.4%, respectively. The majority of patients (95.6%) reported high satisfaction with their decision to get implant treatment in the predoctoral clinic. CONCLUSIONS: In the context of this study, clinical and patient-based outcomes of implant treatment rendered in an academic setting are favorable and comparable to those reported in the literature for restorations completed by experienced dentists.

Instrument Selection and Application Used to Probe Dental Implants.

PURPOSE: The purpose of this study is to survey clinicians' choice of peri-implant instrument selection and the application used to probe dental implants as well as to evaluate peri-implant probing force and pressure applied as compared to that reported in current literature. MATERIALS AND METHODS: 48 clinicians (16 periodontists/periodontal residents, 16 restorative dentists and 16 hygienists) participated in the study. A questionnaire to determine the frequency and method of probing dental implants was provided and subject to the Chi-square test. Each participant was given a choice of three periodontal probes (Marquis, UNC15, Plastic) to use on the typodont and probing force was recorded blindly. Probing force and pressure data were analyzed with ANOVA among subject groups as well as probe types per site; where statistical differences (p < .05) were detected, Tukey's posthoc test was applied. RESULTS: The questionnaire resulted in a variety of answers although the majority demonstrated an agreement on probing implants in everyday practice. There was no significant difference among provider groups in regard to instrument selection, probing forces and pressure in both maxilla and mandible although the mean probing forces and pressures in all provider groups were higher than the suggested value reported in the literature. CONCLUSION: This study indicates that there are variations among clinical provider groups with regard to peri-implant probe instrument type used and forces applied, though these are not statistically significant. Probe tip diameter should be considered to avoid BOP false positives when probing dental implants especially as the forces generally used by the clinicians may be higher than advised.

An In Vivo and Cone Beam Computed Tomography Investigation of the Accuracy in Measuring Alveolar Bone Height and Detecting Dehiscence and Fenestration Defects.

PURPOSE: To investigate cone beam computed tomography (CBCT) accuracy in measuring facial bone height and detecting dehiscence and fenestration defects around teeth. MATERIALS AND METHODS: Patients who were treatment planned for periodontal flap or dental implant surgeries were enrolled (n = 25). CBCT imaging (Carestream CS 9300) was obtained at 0.09-mm voxels (n = 10 patients, 23 teeth) and at 0.18-mm voxels (n = 15 patients, 33 teeth). Facial bone height measurements, from cusp tip to crest of bone height along the long axis of the tooth, and presence or absence of dehiscence or fenestration defects were recorded from CBCT images in triplicates independently by two examiners. The corresponding clinical measurements were made at the time of surgery. Comparisons of CBCT and clinical measurements were made using paired t tests for teeth: anterior and posterior, maxillary and mandibular, with or without restorations, or root canal therapy. Level of agreement between investigators was assessed by concordance correlation coefficients (CCC), Pearson's correlation coefficient (PCC), and Cohen's Kappa. RESULTS: Comparing mean CBCT and clinical measurements, statistically significant differences were noted for 0.09-mm and 0.18-mm voxel sizes, for anterior and posterior teeth, for maxillary and mandibular teeth, for teeth with or without restorations, and for teeth without root canal therapy (P < .05). Clinical and CBCT measurements were similar for teeth with crowns and with root canal therapy (P > .05). CBCT measurements underestimated mean facial bone height from 0.33 ± 0.78 to 0.88 ± 1.14 mm (mean ± SD) and absolute facial bone height values from 0.56 ± 0.35 to 1.08 ± 0.92 mm. Intraexaminer and interexaminer reliability for measuring facial bone height ranged from poor to substantial (PCC = 0.78 to 0.97 and CCC = 0.63 to 0.96, respectively). Interexaminer reliability for detection of dehiscence and fenestration defects ranged from poor to moderate (Cohen's Kappa = -0.09 to 0.66). CONCLUSION: CBCT imaging underestimated facial bone height and overestimated the presence of dehiscence and fenestration defects.

Recombinant Human Platelet-Derived Growth Factor-BB in Human Alveolar Ridge Augmentation: A Review of the Literature.

PURPOSE: The objective of this study was to review the available literature regarding the use of recombinant human platelet-derived growth factor-BB (rhPDGF-BB) in human alveolar ridge augmentation and to assess its effectiveness for this specific use. MATERIALS AND METHODS: Three electronic searches of the MEDLINE database were performed. RESULTS: This review noted a wide range of study protocols, carrier systems, study periods, and outcome measures. CONCLUSION: Within the limits of this literature review, the use of rhPDGF-BB and bone regeneration/ridge augmentation led to greater clinical attachment level gain and bone regeneration prior to implant placement. More controlled clinical studies are needed to establish the effectiveness of rhPDGF-BB in alveolar ridge augmentation.

Accuracy and Reproducibility of Radiographic Images for Assessing Crestal Bone Height of Implants Using the Precision Implant X-ray Locator (PIXRL) Device.

PURPOSE: Assessment of crestal bone levels around implants is essential to monitor success and health. This is best accomplished with intraoral radiographs exposed at 90 degrees to the long axis of the implant, but this can be challenging to achieve clinically. Radiographic paralleling devices produce orthogonal radiographs but traditionally have required access to the implant body for each exposure. This study was conducted to determine if use of the Precision Implant X-ray Locator (PIXRL), a radiographic paralleling device that indexes the implant at the time of surgical placement, can produce orthogonal radiographs of dental implants more accurately than traditional radiologic techniques for assessing crestal bone levels. MATERIALS AND METHODS: Three dental implants were inserted in dry human skulls in supracrestal positions to simulate crestal bone loss (maxillary right first premolar [site 14], maxillary right central incisor [site 11], and mandibular left second premolar [site 35]). The implants were masked with a soft tissue moulage and restored with provisional restorations. Four dental assistants exposed six radiographs using their usual and customary technique and six using the PIXRL device for each implant. A single examiner measured crestal bone levels on the radiographs relative to the implant platform shoulder on the mesial and distal of each implant. Recorded measurements were compared to the known values. Statistical analysis was completed using a generalized linear regression model to analyze the differences, and post-hoc comparisons with pairwise adjustment were applied. RESULTS: The images produced using the PIXRL device were more accurate overall compared to traditional techniques and were also more consistent. The greater degree of accuracy was statistically significant for all sites with the exception of the mesial measurements of the implant at site 11. CONCLUSION: This study demonstrates that the use of the PIXRL device can assist clinicians in obtaining more accurate orthogonal radiographs for assessing crestal bone height and would be a useful tool for researchers utilizing radiographic imaging of implants as a longitudinal measure of implant success and stability.

Factors associated with the clinical response to nonsurgical periodontal therapy in people with type 2 diabetes mellitus.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is a growing health problem worldwide. People with T2DM are at risk of experiencing periodontitis and likely require treatment. Using data from the national multicenter Diabetes and Periodontal Therapy Trial (DPTT), the authors assessed patient-based characteristics associated with the clinical response to nonsurgical therapy. METHODS: The DPTT investigators randomly assigned adults with T2DM (hemoglobin A1c [HbA1c] ≥ 7 percent and < 9 percent) and moderate to advanced periodontitis to receive immediate or delayed therapy (scaling and root planing, oral hygiene instruction, chlorhexidine rinse). The investigators assessed probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), and medical conditions at baseline, three months and six months. Six-month changes in mean PD, CAL and BOP defined the treatment response. Complete data were available for 473 of 514 DPTT participants. The authors used multiple regression models to evaluate participant-level factors associated with the response. RESULTS: More severe baseline PD, CAL and BOP were associated with greater improvements in these same measurements (P < .0001). Hispanic participants experienced greater improvements in PD and CAL than did non-Hispanic participants (P < .0001). Obese participants (those with a body mass index > 30 kilograms per square meter) experienced greater reductions in PD and BOP than did participants who were not obese (P < .001). Age, sex, HbA1c values, diabetes duration, and smoking were not associated with change in any outcome (P > .1). CONCLUSIONS: In patients with T2DM, baseline disease severity was associated with the clinical response to nonsurgical periodontal therapy. Body mass index and Hispanic ethnicity-but not glycemic control, diabetes duration or smoking-also may be useful in predicting clinical changes in this population.

The effect of nonsurgical periodontal therapy on hemoglobin A1c levels in persons with type 2 diabetes and chronic periodontitis: a randomized clinical trial.

IMPORTANCE: Chronic periodontitis, a destructive inflammatory disorder of the supporting structures of the teeth, is prevalent in patients with diabetes. Limited evidence suggests that periodontal therapy may improve glycemic control. OBJECTIVE: To determine if nonsurgical periodontal treatment reduces levels of glycated hemoglobin (HbA1c) in persons with type 2 diabetes and moderate to advanced chronic periodontitis. DESIGN, SETTING, AND PARTICIPANTS: The Diabetes and Periodontal Therapy Trial (DPTT), a 6-month, single-masked, multicenter, randomized clinical trial. Participants had type 2 diabetes, were taking stable doses of medications, had HbA1c levels between 7% and less than 9%, and untreated chronic periodontitis. Five hundred fourteen participants were enrolled between November 2009 and March 2012 from diabetes and dental clinics and communities affiliated with 5 academic medical centers. INTERVENTIONS: The treatment group (n = 257) received scaling and root planing plus chlorhexidine oral rinse at baseline and supportive periodontal therapy at 3 and 6 months. The control group (n = 257) received no treatment for 6 months. MAIN OUTCOMES AND MEASURES: Difference in change in HbA1c level from baseline between groups at 6 months. Secondary outcomes included changes in probing pocket depths, clinical attachment loss, bleeding on probing, gingival index, fasting glucose level, and Homeostasis Model Assessment (HOMA2) score. RESULTS: Enrollment was stopped early because of futility. At 6 months, mean HbA1c levels in the periodontal therapy group increased 0.17% (SD, 1.0), compared with 0.11% (SD, 1.0) in the control group, with no significant difference between groups based on a linear regression model adjusting for clinical site (mean difference, -0.05% [95% CI, -0.23% to 0.12%]; P = .55). Periodontal measures improved in the treatment group compared with the control group at 6 months, with adjusted between-group differences of 0.28 mm (95% CI, 0.18 to 0.37) for probing depth, 0.25 mm (95% CI, 0.14 to 0.36) for clinical attachment loss, 13.1% (95% CI, 8.1% to 18.1%) for bleeding on probing, and 0.27 (95% CI, 0.17 to 0.37) for gingival index (P < .001 for all). CONCLUSIONS AND RELEVANCE: Nonsurgical periodontal therapy did not improve glycemic control in patients with type 2 diabetes and moderate to advanced chronic periodontitis. These findings do not support the use of nonsurgical periodontal treatment in patients with diabetes for the purpose of lowering levels of HbA1c. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00997178.

A prospective, multicenter study of bovine pericardium membrane with cancellous particulate allograft for localized alveolar ridge augmentation.

Resorption of the alveolar ridge may lead to ridge deformities that make dental implant placement difficult or impossible. Augmentation of the alveolar ridge may restore appropriate ridge form to allow implant placement. Forty-four patients with edentulous spaces completed this multicenter prospective trial to clinically and radiographically evaluate the efficacy of a bovine pericardium membrane and a particulate mineralized cancellous bone allograft in promoting lateral ridge augmentation. Overall, 38 of 44 patients (86.4%) were able to receive dental implants in the appropriate restoratively driven position 6 months after ridge augmentation. The mean gain in clinical ridge width after augmentation was 2.61 mm, while radiographically the mean gain in ridge width was 1.65 mm at a level 3 mm apical to the bony crest and 1.93 mm at a level 6 mm apical to the crest. On average, approximately 50% of the graft material added horizontally during surgery was displaced or resorbed during healing. Histomorphometric evaluation of cores taken from the augmented ridge at 6 months revealed that approximately 58% of the tissue volume was vital bone, with 12% residual allograft particles and 30% nonmineralized tissue.

The Human Microbiome Project strategy for comprehensive sampling of the human microbiome and why it matters.

The Human Microbiome Project used rigorous good clinical practice standards to complete comprehensive body site sampling in healthy 18- to 40-yr-old adults, creating an unparalleled reference set of microbiome specimens. To ensure that specimens represented minimally perturbed microbiomes, we first screened potential participants using exclusion criteria based on health history, including the presence of systemic diseases (e.g., hypertension, cancer, or immunodeficiency or autoimmune disorders), use of potential immunomodulators, and recent use of antibiotics or probiotics. Subsequent physical examinations excluded individuals based on body mass index (BMI), cutaneous lesions, and oral health. We screened 554 individuals to enroll 300 (149 men and 151 women, mean age 26 yr, mean BMI 24 kg/m, 20.0% racial minority, and 10.7% Hispanic). We obtained specimens from the oral cavity, nares, skin, gastrointestinal tract, and vagina (15 specimens from men and 18 from women). The study evaluated longitudinal changes in an individual's microbiome by sampling 279 participants twice (mean 212 d after the first sampling; range 30-359 d) and 100 individuals 3 times (mean 72 d after the second sampling; range 30-224 d). This sampling strategy yielded 11,174 primary specimens, from which 12,479 DNA samples were submitted to 4 centers for metagenomic sequencing. Our clinical design and well-defined reference cohort has laid a foundation for microbiome research.

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.

Periodontitis and airway obstruction.

BACKGROUND: The objective of this study was to examine the relationship between airway obstruction and periodontal disease. METHODS: Participants were a subset of 860 community- dwelling, well functioning elderly (aged 70 to 79, blacks and whites, males and females) selected from 2,732 participants enrolled in the Health, Aging, and Body Composition Study (Health ABC). The periodontal evaluations occurred over years 2 and 3 of the study and included four indices of periodontal health: plaque index (PI), gingival index (GI), probing depth (PD), and loss of attachment (LOA). The pulmonary evaluation took place in year 1: conducted according to American Thoracic Society criteria, based on the forced expiratory volume/forced vital capacity (FEV1/FVC) ratio and then using the percent of predicted FEV1 to categorize severity. RESULTS: GI (P = 0.023) and LOA (P = 0.009) were significantly better in participants with normal pulmonary function compared to those with airway obstruction after adjusting for age, race, gender, and field center. When stratified by smoking status and after adjusting for age, race, gender, center, and pack-years, there was a significant association between periodontal health and airway obstruction in former smokers. Within this group, those with normal pulmonary function had significantly better GI (P = 0.036) and LOA (P = 0.0003) scores than those with airway obstruction. All periodontal indices were elevated in smokers regardless of pulmonary status; however, the current smoker group was too small to detect a periodontitis effect. CONCLUSION: While the present cross-sectional study cannot provide direct inference of cause and effect, it does reveal a significant association between periodontal disease and airway obstruction, particularly in former smokers.

Periodontitis and Airway Obstruction.

BACKGROUND: The objective of this study was to examine the relationship between airway obstruction and periodontal disease. METHODS: Participants were a subset of 860 community- dwelling, well functioning elderly (aged 70 to 79, blacks and whites, males and females) selected from 2,732 participants enrolled in the Health, Aging, and Body Composition Study (Health ABC). The periodontal evaluations occurred over years 2 and 3 of the study and included four indices of periodontal health: plaque index (PI), gingival index (GI), probing depth (PD), and loss of attachment (LOA). The pulmonary evaluation took place in year 1: conducted according to American Thoracic Society criteria, based on the forced expiratory volume/forced vital capacity (FEV1 /FVC) ratio and then using the percent of predicted FEV1 to categorize severity. RESULTS: GI (P = 0.023) and LOA (P = 0.009) were significantly better in participants with normal pulmonary function compared to those with airway obstruction after adjusting for age, race, gender, and field center. When stratified by smoking status and after adjusting for age, race, gender, center, and pack-years, there was a significant association between periodontal health and airway obstruction in former smokers. Within this group, those with normal pulmonary function had significantly better GI (P = 0.036) and LOA (P = 0.0003) scores than those with airway obstruction. All periodontal indices were elevated in smokers regardless of pulmonary status; however, the current smoker group was too small to detect a periodontitis effect. CONCLUSION: While the present cross-sectional study cannot provide direct inference of cause and effect, it does reveal a significant association between periodontal disease and airway obstruction, particularly in former smokers.