An evidence-based teaching approach enhances student learning of periodontal disease pathogenesis.

PURPOSE/OBJECTIVES: To evaluate the effects of implementing an evidence-based teaching approach (EBTA) in a traditional dental curriculum course on predoctoral dental students' knowledge and attitudes about evidence-based dentistry, and to determine its benefit on enhancing students' academic performance. METHODS: Fundamentals of periodontics for first-year dental students (D1, n = 100) span a period of 12 weeks. In the first 6 weeks, we teach the basic principles of periodontal disease pathogenesis and introduce the concepts of EBTA (basics of research study design, statistical principles, literature search, and critically analyzing the evidence) without active implementation. In the second 6 weeks, we build on the initial knowledge of periodontal disease pathogenesis and actively implement EBTA activities to enhance the learning of the course content. Pre- and post-EBTA implementation, students completed a validated survey assessing students' knowledge, attitudes, access of evidence, and confidence related to evidence-based dentistry. Midterm and final grades were used to assess student academic performance. RESULTS: Post-EBTA implementation survey responses showed: significant increase in students' knowledge regarding critical appraisal of the literature (p = 0.0001), significant improvement in students' attitudes about evidence-based dentistry (p = 0.0001), significant increase in students' frequency of accessing evidence from various sources (p = 0.01), and significant increase in students' confidence in evaluating various aspects of a published research report (p = 0.009). Post-EBTA final grade scores were significantly higher than pre-EBTA midterm grade scores (p = 0.0001). CONCLUSIONS: Integrating an EBTA within a traditional dental curriculum course improves students' knowledge and attitudes about evidence-based dentistry as well as enhances students' academic performance.

Obesity Is Associated with a Weakened Gingival Inflammatory Cytokine Response.

Background and Objectives: An obesity-related elevated body mass index (BMI) across life is associated with chronic low-grade inflammation and increased levels of C-reactive protein (CRP) in blood. CRP is a marker and promoter of inflammation. The objectives of this study were to examine the effect of obesity on the relationship between peripheral and gingival CRP levels and to examine the effects of gingival CRP levels on gingival fluid inflammatory cytokines in periodontitis-resistant obese individuals. Materials and Methods: Thirty-nine participants in good periodontal health were recruited. Twenty patients were classified as lean and nineteen as obese based on their BMI levels. A thorough periodontal assessment was carried out. Gingival crevicular fluid (GCF) and blood samples were collected. Both GCF and blood samples were analyzed for interleukin-1ß (IL-1ß), interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10), interleukin-17A (IL-17A), and CRP. Results: GCF CRP levels were significantly higher in the obese than in the lean individuals. No statistically significant differences were noted between the two groups in either GCF or blood in terms of any of the inflammatory cytokine levels. IL-17A was not detected in the GCF of most subjects in both groups. GCF CRP levels were positively associated with blood CRP levels, and the association tended to be stronger in the obese individuals. GCF CRP showed no associations with GCF IL-10 in both groups. Although GCF CRP levels were positively associated with multiple GCF inflammatory cytokines (e.g., IL-1ß, IL-6, IL-8, and TNF-α) in all subjects, the associations tended to be weaker in the obese individuals (e.g., IL-1ß, IL-6, and TNF-α). Furthermore, the levels of the GCF inflammatory cytokines IL-6 and TNF-α were decreased in the obese individuals. Conclusions: Obesity unfavorably influences the relationship between blood and GCF CRP levels and promotes increased CRP levels in GCF. Collectively, the findings suggest a weakened inflammatory cytokine response in the gingival tissues of obese individuals.

Metabolomic profiles of obesity and subgingival microbiome in periodontally healthy individuals: A cross-sectional study.

AIM: Since blood metabolomic profiles of obese individuals are known to be altered, our objective was to examine the association between obesity-related metabolic patterns and subgingival microbial compositions in obese and non-obese periodontally healthy individuals. MATERIALS AND METHODS: Thirty-nine periodontally healthy subjects were enrolled. Based on body mass index scores, 20 subjects were categorized as lean and 19 as obese. A comprehensive periodontal examination was performed. Subgingival plaque and blood samples were collected. Plaque samples were analysed for bacteria using 16S rDNA sequencing. Untargeted metabolomic profiling (mass spectrometry) was used to quantify metabolites in serum. RESULTS: Obese subjects were statistically associated with several periodontopathic taxa including Dialister invisus, Prevotella intermedia, Prevotella denticola, Fusobacterium nucleatum_subsp.vincentii, Mogibacterium diversum, Parvimonas micra and Shuttleworthia satelles. In obese individuals, an amino acid-related metabolic pattern was elevated; however, there was a decrease in metabolic patterns related to lipids and cofactor/vitamins. These metabolic perturbations were associated with multiple subgingival bacterial species that differentiated lean from obese individuals. CONCLUSIONS: Obesity-related perturbations in circulating blood metabolites are associated with the development of periodontopathic bacterial colonization in the subgingival microbiome and consequently may increase the risk for periodontal disease in obese individuals.

Oral Squamous Papilloma Mimicking Oral Verrucous Leukoplakia.

The human papillomavirus (HPV) is a non-enveloped DNA virus that causes a variety of skin and mucosal lesions. This report reviews a likely HPV-related lesion of oral squamous cell papilloma clinically mimicking oral verrucous leukoplakia. A 71-year-old white male presented with a raised white lesion on the palatal mucosa. It felt hard on palpation and had a sessile fixed base, and a rough verrucous surface. The lesion was fully excised. Histopathology showed short, thin, fingerlike projections lined by stratified squamous epithelium with thin central connective tissue cores. The epithelial superficial layers demonstrated focal koilocytotic changes suggestive of an HPV infection. High-risk HPV-related lesions have the potential to turn malignant. Early diagnosis and management are critical to preventing serious complications.

Cross-sectional comparisons of subgingival microbiome and gingival fluid inflammatory cytokines in periodontally healthy vegetarians versus non-vegetarians.

BACKGROUND: Vegetarian diets are known to reduce inflammation. The objective of this study was to test the hypothesis that reduced inflammation associated with a vegetarian diet would promote a more commensal subgingival bacterial profile. METHODS: A total of 39 periodontally healthy subjects (PD ≤3 mm, bleeding on probing <10%) were enrolled. Dietary intake was assessed by a food frequency questionnaire. A comprehensive periodontal examination was performed. Gingival crevicular fluid (GCF) and subgingival plaque samples were collected. GCF samples were assessed for interleukin-1ß, interleukin-6, interleukin-8, tumor necrosis factor-alpha, and interleukin-10. Plaque samples were analyzed for bacteria using 16S rDNA sequencing on an Illumina platform. GenBank database was used for taxonomy classification. RESULTS: Twenty-three subjects were categorized as vegetarian and 16 non-vegetarians. Clinical periodontal measures and GCF cytokine levels were statistically comparable between the two groups. Measures of microbial richness and alpha diversity were also comparable between the two dietary groups. Vegetarians harbored higher levels of phyla associated with gingival health (Actinobacteria, and Proteobacteria). Two species known to be associated with periodontitis (Mogibacterium timidum and Veillonella rogosae) were prominent in non-vegetarians. Pearson's correlations between GCF inflammatory cytokines and microbial taxa differed between vegetarians and non-vegetarians. In vegetarians, the anti-inflammatory cytokine IL-10 positively correlated with two species known to be associated with periodontal health (Peptidiphaga sp. HMT183 and Rothia aeria). CONCLUSIONS: Diet is directly and indirectly associated with the microbial composition of subgingival plaque. A vegetarian diet may promote a subgingival microbiota associated with periodontal health.

A comparison of computed tomography scans and digital periapical radiographs ridge height measurements.

To investigate the agreement between computerized tomography scans (CT) and intraoral periapical digital radiographs (PA) alveolar ridge height measurements in maxillary and mandibular posterior regions. We reviewed 100 implant patient radiographic records and identified 27 mandibular sites in 19 patients and 23 maxillary sites in 13 patients with available CT scans and matching PA radiographs. The distance from the crest of the ridge to the floor of the maxillary sinus or to the superior border of the inferior alveolar canal was measured. PAs were measured with Dexis software v. 8.0 and CTs were measured with Simplant software v. 11.02. Two examiners (RJ and MM) recorded the measurements separately; each examiner recorded two readings. The average of the 4 readings was used for data analysis. Absolute agreement: Paired t test comparing ridge-height measurements between the two imaging methods showed no differences for maxillary sites (P > 0.2) and significant differences for the mandibular sites (CT > PA, P = 0.0009). Relative agreement: Kendall rank correlation analysis of ridge-height measurements between the 2 imaging methods showed a high positive correlation for maxillary sites (Kendall's tau = 0.76, P = 0.0001) and moderate correlation for the mandibular sites (Kendall's tau = 0.46, P = 0.001). Maxillary PAs tend to approximate CT ridge-height measurements. By contrast mandibular PAs tend to underestimate the distance from the crest of the ridge to the inferior alveolar canal.

Aggressive forms of periodontitis secondary to systemic disorders.

A number of systemic disorders increase a patient's susceptibility to destructive periodontitis and have impacts on periodontal disease progression and severity. The underlying factors are usually genetic and are mainly related to alterations in the immune response and in certain endocrine functions, leading to various syndromes in which periodontitis and/or early tooth loss are secondary manifestations. Neutrophils are important immune defense cells that play a significant role in controlling the spread of microbial plaque infections in the dentogingival region. This review focuses on a selected group of systemic disorders that are associated with alterations in either neutrophil counts (quantitative disorders) or function (qualitative disorders), and defects in the mineralization of bone and dental tissues. In most of these diseases controlling the periodontal disease progression is very challenging. Proper diagnosis is a prerequisite for proper management of the periodontal problem. Future advances in research, including gene targeting and the resolution of enzyme deficiencies, may bring about remedies of the underlying systemic disorders and may significantly improve the outcome of periodontal treatment in these patients.

Neutrophil function and periodontitis in alcohol-dependent males without medical disorders.

BACKGROUND: Periodontitis and immune dysfunction are often reported in alcohol-dependent patients. Our objectives were to investigate the effects of alcohol exposure on neutrophil function and the associated consequential effects on the periodontium in a group of African American (AA) males with documented history of alcohol use without medical complications. METHODS: Thirty-three AA males with documented history of alcohol use were included in this analysis. All subjects were free from systemic illness. Blood levels of gamma-glutamyl transpeptidase (GGTP) were determined and used as a measure of alcohol consumption. Periodontal evaluations including attachment levels (AL) were recorded on 6 sites per tooth. Enumerative and functional neutrophil measures were obtained. RESULTS: GGTP blood levels inversely associated with neutrophil bacterial killing (NBK) (p = 0.04). Regression analysis, adjusting for risk factors associated with periodontitis, showed an inverse association between NBK and percent of sites with AL > or = 5 mm (p <0.05) and a direct significant interaction between GGTP (> 51 international units) and increasing NBK activity on percent of sites with AL > or = 5 mm (p < 0.05). CONCLUSIONS: In AA males with excessive alcohol use, neutrophils show depressed NBK. Depressed NBK was not associated with loss of periodontal attachment in this population. Furthermore, AA males with excessive alcohol use and uncompromised neutrophil function are at greater risk of periodontal tissue damage.

Salivary thiol levels and periodontal parameters assessed with a chromogenic strip.

Periodontitis tends to be associated with bacteria that use sulfate as an energy source and produce thiol compounds that contain sulfhydryl (-SH) groups. This study used a chromogenic thiol-detecting strip to investigate whole saliva -SH concentration (SS) in subjects with and without periodontal disease. Ninety-six subjects were enrolled; all underwent periodontal evaluations, including plaque index (PI), gingival index (GI), probing depth measurements (PD), and attachment levels (AL). Subjects were divided into 3 groups: those who were periodontally healthy (n = 17), those with gingivitis (n = 54), and those with periodontitis (n = 25). Of the 96 subjects, 33% (n = 32) were cigarette smokers. A chromogenic strip was used to collect a whole saliva sample from the mouth. Color reaction was scored based on a color chart. Good-to-moderate correlations were found between SS scores and PI (r = 0.47, P = 0.0001), GI (r = 0.45, P = 0.0001), PD (r = 0.42, P = 0.0001), and AL (r = 0.30, P = 0.002). Analysis of variance showed significant differences in SS scores among the 3 study groups (P = 0.0001); post-hoc analysis showed higher SS scores in subjects with periodontitis than in those without (P = 0.05). Logistic regression, adjusting for smoking, showed the odds ratio of periodontitis increased by a factor of 12.76 for each increase of one unit of measure of SS. These results indicate that assessing whole saliva thiol levels with a chromogenic strip could be used as a screening test for periodontal diseases.

Probing and scaling instrumentation on implant abutment surfaces: an in vitro study.

PURPOSE: To investigate surface roughness on the apical collar of implant abutments caused by probing and scaling instruments. MATERIALS AND METHODS: Fourteen transmucosal abutments (BioHorizons, Atlanta, GA) and 4 instruments: UNC-15 metal probe, Periowise plastic probe, McCall SM 17/18 metal scaler, and universal plastic scaler were used to conduct the study. Four abutments were used for nontreated measures, and 10 abutments were treated with the 4 indicated instruments. Surface roughness was assessed with a contact profilometer. RESULTS: Analysis of variance showed significant differences in surface roughness between the treated and untreated surfaces (P < 0.0001). Add hoc analysis using Tukey-Kramer honestly significant difference test showed no statistical differences between untreated measures and metal probe measures. On the other hand, statistical differences were noted between untreated measures with plastic probe measures (P = 0.05), plastic scaler measures (P = 0.05), and metal scaler measures (P = 0.05). The metal scaler measures were higher than plastic probe measures (P = 0.05) and plastic scaler measures (P = 0.05). CONCLUSIONS: Probing around implant abutments with a metal probe seems to have no effect on abutment surfaces. In contrast, instrumentation with scalers (metal and plastic) and plastic probe may cause surface roughness.

A clinical investigation of the association of a biochemical chairside assay and periodontal parameters.

OBJECTIVE: This study examines the relationship between the values of a research-use only biochemical assay that detects sulfur/protein compounds in gingival crevicular fluid (GCF) and clinical measures of periodontal status. METHODS: Seventy-five subjects were enrolled; two were excluded. Mean age (SD) was 44.73 (19.61); age range, 23 to 85; men, 55%; white, 44%. Periodontal evaluations, including plaque index (PI), gingival index (GI), clinical periodontal attachment levels (AL), and bleeding on probing (BOP) were performed on six sites per tooth. Subjects were divided into three groups: periodontally healthy (no loss of attachment and no gingival bleeding, 18 subjects); gingivitis (no loss of attachment and presence of gingival bleeding, 32 subjects); and periodontitis (loss of attachment > 5 mm in five or more teeth, 23 subjects). Gingival crevicular fluid was collected from four separate sites, one site per quadrant, and processed for sulfur compounds (GCF.tx) and protein compounds (GCF.pt). RESULTS: Analysis of variance showed that GCF.pt scores differed between the three periodontal groups (p = 0.01). Ad hoc Tukey HSD test showed periodontally diseased subjects (gingivitis and periodontitis) had higher GCF.pt scores than periodontally healthy subjects (p = 0.05). Correlation analysis showed moderate significant associations between clinical periodontal measures and both GCF.tx and GCF.pt scores. CONCLUSION: Our results suggest that a chairside biochemical assay, capable of measuring sulfur and protein levels in GCF, has potential as an adjunct diagnostic test for periodontal diseases.

Association of interleukin-1 polymorphisms with periodontitis in Down syndrome.

This study examined the association of IL1 genetic polymorphisms (IL-1A +4845, IL-1B +3954 & IL-1RN +2018) with periodontal disease status of Down syndrome (DS) individuals. Fifty-four DS patients (18-56 yr, 48.15% male, 77.78% Caucasians) were recruited from the Georgia Regional Hospital (GRH) health care system. Two comparable groups (71 mentally retarded patients and 87 control subjects) were also recruited. All subjects were nonsmokers. Periodontal evaluations (plaque index, gingival index, bleeding-on probing and clinical attachment levels (AL)), personal and professional dental care habits were recorded. Blood was collected by a venipuncture. The IL-1A +4845, IL-1B +3954 & IL-1RN +2018 loci were genotyped by the TaqMan assay. No statistically significant differences were noted in the distribution of IL-1 gene polymorphisms between the three groups. The IL-1 variant genotypes varied by race; for both IL-1A and IL-1RN, the variant gene was significantly more prevalent among whites than non-whites (ps > 0.1). ANCOVA, which also adjusted for age, showed a 3-way interaction among dental visits, gene variation and Down status [(F(1, 179) = 3.96, P = 0.048 in White subjects and F(1, 241) = 2.96, P = 0.087 in all subjects). Post-hoc t-tests confirmed lower levels of AL in IL-1RN-variant Down subjects receiving more frequent dental visits (P < 0.05). ANCOVA, which also adjusted for age, showed an interaction between IL-1A/B gene variation and Down status (F(1, 174) = 3.04, P = 0.083 in White subjects and F(1, 235) = 3.72, P = 0.055 in all subjects). Post-hoc t-tests confirmed lower levels of AL in IL-1A/B-variant Down subjects (P < 0.05). The distribution of variant IL-1 genes in DS subjects was not different from the general population. However the association between the carriage of the IL-1 rare alleles and periodontitis differed between the Down and non-Down subjects. The carriage of the IL-1 rare alleles in the Down subjects tended to confer a protective effect against loss of periodontal attachment.

Periodontitis associated with Chediak-Higashi syndrome in a young African American male.

BACKGROUND: Chediak-Higashi syndrome (CHS) is a rare autosomal recessive genetic disease. The primary defect is abnormal granule formation in the cells secondary to a mutation of a lysosomal trafficking regulator protein. CHS patients have immune system abnormalities, bleeding abnormalities, and multiple infections including periodontitis. METHODS: A 13-year-old African American male presented with severe gingival inflammation, generalized gingival bleeding, and tooth looseness. Comprehensive dental, medical and laboratory evaluations were performed. RESULTS: All teeth exhibited excessive mobility. The gingival tissues were swollen and bled easily. Most sites had probing depth in excess of 10 mm. Dental radiographs showed advanced generalized alveolar bone loss. Areas of skin depigmentation were noted. Blood smear showed presence of intracellular large granules in white blood cells. Platelet function was altered. Gingival histopathology showed an intense chronic inflammatory cell infiltrate and presence of numerous filamentous bacteria. Subgingival microbiological culture showed the presence of Porphyromonas gingvalis, Prevotella intermedia and Tannerella forsythia. Based on the periodontal, medical and laboratory findings a diagnosis of CHS was established. Because of the advanced periodontal condition and the risk of fatal bacterial infections, exodontias were performed. Because of platelet abnormalities the patient developed postoperative bleeding complications that required management with coagulation factor 7. CONCLUSIONS: Advanced periodontitis is an important symptom of CHS and may be the first step in the diagnosis of the condition. Due to the weakened immunity of CHS patients, periodontal management is usually unsuccessful. Tooth extractions are recommended to eliminate the periodontal problems and reduce the risk of fatal bacterial infections.

Periodontal health in Down syndrome: contributions of mental disability, personal, and professional dental care.

Fifty-five dentate patients with Down syndrome (DS) and 74 with mental disability non-Down (MR) were compared to 88 control subjects. Subjects in the MR and Control groups were matched by gender and ethnicity to subjects with DS. All subjects were nonsmokers. Periodontal evaluation included plaque index (PI), gingival index (GI), bleeding on probing (BOP), and clinical periodontal attachment levels. Caries and missing teeth were recorded. Measures of personal dental hygiene and the frequency of professional dental care were also recorded. Most subjects brushed their teeth at least once per day, but did not floss. Both groups with DS and MR had significantly more missing teeth, more BOP, and higher GI and PI levels than the control group. Patients with DS had more attachment loss (AL) than the other two groups (p < .001). Increased AL in patients with DS was not associated with differences in socioeconomic status, personal/professional dental care, or mental disability.

Effect of implant design on initial stability of tapered implants.

Implant design is one of the parameters for achieving successful primary stability. This study aims to examine the effect of a self-tapping blades implant design on initial stability in tapered implants. Polyurethane blocks of different densities were used to simulate different bone densities. The two different implant designs included one with self-tapping blades and one without self-tapping blades. Implants were placed at 3 different depths: apical third, middle third, and fully inserted at 3 different densities of polyurethane blocks. A resonance frequency (RF) analyzer was then used to measure stability of the implants. Repeated-measures analysis of variance was used to examine the effect of implant design, insertion depth, and block density on RF. Analysis of covariance was used to examine the strength of association between RF and the aforementioned factors. In both medium-density (P = .017) and high-density (P = .002) blocks, fully inserted non-self-tapping implants showed higher initial stability than self-tapping implants. No differences were noted between the 2 implant designs that were not fully inserted. The highest strength of association was with insertion depth (standardized beta [std beta] = -0.60, P = .0001), followed by block density (std beta = -0.15, P = .0002). Implant design showed a weak association (std beta = -0.07, P = .09). In conclusion, fully inserted implants without self-tapping blades have higher initial stability than implants with self-tapping blades. However, the association strength between implant design and initial stability is less relevant than other factors, such as insertion depth and block density. Thus, if bone quality and quantity are optimal, they may compensate for design inadequacy.

Dental care and oral disease in alcohol-dependent persons.

Dental/Oral health of alcohol-dependent persons and substance abusers is often neglected. It is not clear that alcohol dependence has effects on oral health beyond those expected in nonalcoholic persons of similar socioeconomic status (SES). Study objectives were to examine the personal dental care habits, ability to access professional dental care, and the types of services received and to examine their effect on the oral health of alcohol-dependent persons and substance abusers. Forty Diagnostic and Statistical Manual of Mental Disorders, Third Edition Revised-diagnosed alcohol-dependent persons and a comparison group of 25 non-alcohol-dependent subjects matched for race, age, gender, and SES were recruited. Subjects were medically healthy. Each subject received a comprehensive oral/dental examination, and an interview was conducted to record personal dental hygiene habits, ability to access professional dental care, and types of dental services provided. No statistical differences were found between the oral care habits of the groups. Forty-four percent of all subjects had access to charity professional dental care. Tooth extraction was the main dental service they received. Seventy-five percent of subjects brushed their teeth once or more per day. In the non-alcohol-dependent group, brushing frequency was inversely associated with plaque levels (p < .05); in the alcohol-dependent group, brushing frequency showed no statistical effect on plaque levels. Access to professional dental care was inversely associated with periodontitis in the alcohol-dependent group (p < .05). Alcohol dependence may increase plaque levels above that seen in race, gender, age, and SES-matched controls, but professional dental care can limit the subsequent development of periodontal disease in these people.

Radiographic assessment of periodontitis in African-Americans with Down syndrome.

OBJECTIVE: Down syndrome (DS) is a neurodevelopmental genetic disorder affecting millions of Americans. Previous studies, mainly in Caucasians, have shown periodontitis to be a major oral health problem among DS patients. Other research has shown that African-Americans (AA) are more susceptible to periodontitis than Caucasians. Our objective was to determine if DS negatively affects the already impaired periodontal status of AAs. METHODS: Radiographic alveolar bone levels were used to determine periodontal status. Full-mouth series of intraoral periapical (PA) radiographs of 25 AA DS patients (age range 18-64 years, 36% males) were randomly selected from a special care dental center for the handicapped. PA radiographs of 25 AA mentally challenged (MC) non-Down patients were also selected from the same center. MC patients were matched to DS patients on variables of race, age, sex, socioeconomic status and institutionalized care. All periapical radiographs were taken with a long cone paralleling technique under normal clinical practice conditions. Under standardized viewing conditions, the distance from the cementoenamel junction to the interproximal alveolar crest on both the mesial and distal surfaces of each fully erupted permanent tooth present was measured. A paired samples t-test was used to compare the radiographic bone levels of DS and MC subjects. RESULTS: All subjects showed sites with bone loss > or = 3 mm. Whole mouth mean (SD) bone level for DS subjects was 3.0 (1.5) mm and for MC subjects it was 1.9 (1.1) mm, p = 0.001. This finding was replicated in the various regions in the mouth where DS patients showed greater bone loss than MC patients in anterior regions (incisors and canines, p = 0.001), in posterior regions (molars and premolars, p = 0.007), in maxillary regions (p = 0.001) and in mandibular regions (p = 0.005). CONCLUSIONS: Periodontitis is a problem in AA patients. Adding the genetic disorder of DS to AA race imposes additional risks for periodontitis.