Investigating the Response of Human Neutrophils to Hydrophilic and Hydrophobic Micro-Rough Titanium Surfaces.

Various treatments have been used to change both the topography and chemistry of titanium surfaces, aiming to enhance tissue response and reduce healing times of endosseous implants. Most studies to date focused on bone healing around dental implants occurring later during the healing cascade. However, the impact of the initial inflammatory response in the surgical wound site on the success and healing time of dental implants is crucial for implant integration and success, yet it is still poorly understood. The purpose of this study was to investigate the effect of titanium surface hydrophilicity on the response of human neutrophils by monitoring oxygen radical production, which was measured as chemiluminescence activity. Materials and Methods: Neutrophils were isolated from human donors' blood buffy coats using the double sucrose gradient method. Neutrophils were exposed to both hydrophilic and hydrophobic titanium surfaces with identical topographies in the presence and absence of human serum. This resulted in six experimental groups including two different implant surfaces, with and without exposure to human serum, and two control groups including an active control with cells alone and a passive control with no cells. Two samples from each group were fixed and analyzed by SEM. Comparisons between surface treatments for differences in chemiluminescence values were performed using analysis of variance ANOVA. Results and Conclusion: In the absence of exposure to serum, there was no significant difference noted between the reaction of neutrophils to hydrophilic and hydrophobic surfaces. However, there was a significant reduction in the mean and active chemiluminescence activity of neutrophils to serum-coated hydrophilic titanium surfaces than to serum-coated hydrophobic titanium surfaces. This suggests that surface hydrophilicity promotes enhanced adsorption of serum proteins, which leads to decreased provocation of initial immune cells and reduction of local oxygen radical production during wound healing. This can help explain the faster osseointegration demonstrated by hydrophilic titanium implants.

Association Between Obstructive Sleep Apnea and Periodontitis Among Male Adults Attending a Primary Healthcare Facility in Jordan.

PURPOSE: To determine the association between periodontitis and a high risk for obstructive sleep apnea (HR-OSA). MATERIALS AND METHODS: A sample of 296 males with a mean (±SD) age 40 (8.5) years was selected. Subjects who scored positive in two or more categories of the Berlin questionnaire were considered as having HR-OSA. RESULTS: Based on the self-reported symptoms of obstructive sleep apnea, 15% of patients were considered as HROSA. Patients with HR-OSA showed higher probing pocket depth (PPD) and clinical attachment level (CAL) compared with those with low risk for obstructive sleep apnea (LR-OSA)-2.35±0.69 vs 1.97±0.34 (p=0.000) and 2.95±0.82 vs 2.12±0.55 (p=0.000), respectively. Patients with HR-OSA were more likely to have periodontitis (OR=2.3; 95% CI: 1.03/5.10) compared to patients with LR-OSA. The prevalence of periodontitis varied significantly only among patients according to their response to category 1 (37% responded positively and 20% responded negatively, p=0.003). When the OSA variable was replaced by the individual categories (1, 2 and 3), patients with a positive category 1 (OR=2.27; 95% CI: 11.14/4.45) were more likely to have periodontitis than were patients with a negative response. CONCLUSION: The risk of finding periodontitis in HR-OSA patients was approximately double that of LR-OSA patients. Habitual snoring was also associated with increased risk for periodontitis.

Association between edentulism and angina pectoris in Mexican adults aged 35 years and older: a multivariate analysis of a population-based survey.

BACKGROUND: The possible association between oral infection and chronic inflammation and cardiovascular disease risk has been studied intensively. The present study is designed to determine the strength of association between edentulism and angina pectoris in Mexican adults aged 35 years and older. METHODS: Using the tools and sampling strategies of the World Health Survey of the World Health Organization, cross-sectional data were collected in Mexico in the National Performance Assessment Survey (probabilistic, multistage, and cluster sampling). Dental information was available for 20 of the 32 states of Mexico. Angina and edentulism are self-reported in this study. Statistical analysis was performed using binary logistic regression adjusting for complex samples. RESULTS: A total of 13,966 participants, representing a population of 29,853,607 individuals, were included. Of the complete study population, 3,052,263 (10.2%) were completely toothless, and 673,810 (2.3%) were diagnosed with angina pectoris. After adjusting for smoking, alcohol consumption, diabetes, body mass index, and sex, the effect of edentulism on angina was modified by age (interaction), being more marked in the younger age group (odds ratio [OR] = exp(2.5597) =12.93) than in the older individuals surveyed (OR = exp(2.5597 + (-0.0334)) =12.51). Additionally, low physical activity (OR = 1.51; 95% confidence interval [CI] = 1.03 to 2.22) and higher socioeconomic status (OR = 1.37; 95% CI = 1.00 to 1.90) were more likely to be associated with angina pectoris. CONCLUSIONS: Overall, the results of this study, conducted in a representative sample of Mexican adults, suggest that an association exists between edentulism and angina pectoris. Additional studies are necessary to elucidate the underlying mechanism for this association.

Gingival evaluation of the pediatric cardiac patient.

PURPOSE: Children with congenital cardiovascular diseases (CCDs) who suffer from dental diseases have an increased risk of infective endocarditis. In the light of recent evidence, oral inflammatory diseases may also increase the severity of their cardiovascular condition. The purpose of this study was to evaluate the gingival status of children with congenital cardiovascular diseases in comparison to healthy children. METHODS: Fifty 7- to 13-year-old children were included. The test group comprised 25 CCD children subdivided into three groups: (1) unrepaired ventricular septal defect; (2) aortic valve stenosis; and (3) coarctation of the aorta. The control group consisted of 25 healthy age- and gender-matched children. Gingivitis, plaque, calculus, and recession were measured on six sites per tooth on 12 teeth. RESULTS: CCD children had significantly more gingivitis (P<.001), plaque (P<.001), recession (P>.02), and calculus (P<.001) than controls. Among the CCDs groups, no statistically significant differences were found for gingivitis, plaque, or recession. CONCLUSIONS: Children with congenital cardiovascular diseases had a higher prevalence of periodontal disease, evidenced by gingivitis, plaque, calculus, and recession. These children should be evaluated periodontally and their oral health monitored on a 3-month basis to prevent disease development, benefit cardiovascular condition, prevent endocarditis, and improve quality and longevity of life.

Recent advances in the development of GTR/GBR membranes for periodontal regeneration--a materials perspective.

UNLABELLED: Periodontitis is a major chronic inflammatory disorder that can lead to the destruction of the periodontal tissues and, ultimately, tooth loss. To date, flap debridement and/or flap curettage and periodontal regenerative therapy with membranes and bone grafting materials have been employed with distinct levels of clinical success. Current resorbable and non-resorbable membranes act as a physical barrier to avoid connective and epithelial tissue down-growth into the defect, favoring the regeneration of periodontal tissues. These conventional membranes possess many structural, mechanical, and bio-functional limitations and the "ideal" membrane for use in periodontal regenerative therapy has yet to be developed. Based on a graded-biomaterials approach, we have hypothesized that the next-generation of guided tissue and guided bone regeneration (GTR/GBR) membranes for periodontal tissue engineering will be a biologically active, spatially designed and functionally graded nanofibrous biomaterial that closely mimics the native extra-cellular matrix (ECM). OBJECTIVE: This review is presented in three major parts, including (1) a brief overview of the periodontium and its pathological conditions, (2) currently employed therapeutics used to regenerate the distinct periodontal tissues, and (3) a review of commercially available GTR/GBR membranes as well as the recent advances on the processing and characterization of GTR/GBR membranes from a materials perspective. SIGNIFICANCE: Studies of spatially designed and functionally graded membranes (FGM) and in vitro antibacterial/cell-related research are addressed. Finally, as a future outlook, the use of hydrogels in combination with scaffold materials is highlighted as a promising approach for periodontal tissue engineering.

Controlling bacterial contamination of dental impression guns.

BACKGROUND: Dental impression material handgun cartridge dispensers are contaminated easily during clinical use. The authors attempted to quantify contamination by bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), of impression guns used in an academic dental clinic after five infection-prevention protocols were followed. METHODS: The authors obtained samples from four commercially available impression guns at four specific sites (button, handle, latch, trigger) after routine clinical use, disinfection, steam sterilization (also known as autoclaving), steam sterilization followed by use of plastic impression gun covers and steam sterilization followed by use of plastic impression gun covers and disinfection. RESULTS: The authors found that after routine clinical use, bacteria-including MRSA-heavily contaminated the impression guns. After the impression guns underwent disinfection, there was a 6 percent decrease in bacterial counts. The use of steam sterilization achieved sterility without harming the impression guns. Use of steam-sterilized impression guns with plastic impression gun covers decreased bacterial isolates by approximately 60 percent. Use of steam-sterilized impression guns plus covers and disinfection resulted in an approximately 95 percent reduction in contamination. CONCLUSIONS: The use of common infection-prevention methods appears to reduce the bacterial counts, including those of MRSA. Bacterial contamination was lowest after steam sterilization, followed by the use of plastic impression gun covers and disinfection. CLINICAL IMPLICATIONS: Use of contaminated impression guns on successive patients could increase the risk of causing cross-transmission of disease. The use of sterilization, plus plastic impression gun covers and disinfection, for impression guns after each use could be an effective and practical infection-control method for dental practices.

Endotoxemia and the host systemic response during experimental gingivitis.

AIM: To assess endotoxemia episodes and subsequent changes in serum inflammatory biomarkers using the experimental gingivitis model. MATERIALS AND METHODS: Data from 50 healthy black and white adult males and females were compared for serum concentrations of endotoxin, and serum biomarkers [neutrophil oxidative activity, interleukin (IL)-1ß, IL-6, IL-8, C-reactive protein (CRP), and fibrinogen] at baseline, at 3 weeks of experimental gingivitis, and after 2 weeks of recovery. Means were compared using repeated measures analysis of variance. RESULTS: Endotoxemia was reported in 56% of the serum samples at 3 weeks of induced gingivitis. At 2 weeks of recovery, endotoxin levels decreased to levels similar to those reported at baseline. Neutrophil oxidative activity increased significantly following 3 weeks of gingivitis versus baseline (p<0.05). In the endotoxin-negative group this increase was associated with the black subjects whereas in the endotoxin-positive group change in neutrophil activity was driven by the female subpopulation. Serum cytokines, CRP, and fibrinogen levels did not change during the study. CONCLUSIONS: Experimental gingivitis was associated with endotoxemia and hyperactivity of circulating neutrophils, but not with changes in systemic levels of cytokines and acute-phase proteins. This may be attributed to the mild nature and the short duration of the induced gingivitis.

Responses of human neutrophils to nicotine and/or Porphyromonas gingivalis.

BACKGROUND: Tobacco smoking is considered a major modifiable risk factor for periodontal disease. Nicotine is the addictive ingredient in tobacco and has been shown to affect multiple cellular processes. Neutrophils are the first line of host defense and are critical cells in the maintenance of periodontal health through their role in the control of bacteria, but they can also contribute to the progression of periodontal disease by the production and release of reactive oxygen species (ROS). Virulence factors from periodontal pathogens, such as Porphyromonas gingivalis (Pg), stimulate the respiratory burst of neutrophils. The objective of this study is to explore the oxidative activity of neutrophils when stimulated with Pg, nicotine, or both. METHODS: Neutrophils were separated from buffy coats by the double dextran gradient method. The generation of ROS by neutrophils was determined using luminol-dependent chemiluminescence assays. The reaction was followed for 90 minutes, and the neutrophil activation was recorded as the total integrated energy output. RESULTS: The Pg and Pg plus nicotine groups had a significantly higher active and peak chemiluminescence than the nicotine group (all with P <0.0001). The Pg and Pg with nicotine groups were not significantly different (P = 0.90). CONCLUSION: In the presence of Pg, the nicotine did not further enhance the ROS release by the neutrophils, suggesting that the bacteria induced the maximum ROS release in this model system.

Changes in gingival dimensions following connective tissue grafts for root coverage: comparison of two procedures.

BACKGROUND: The purpose of this study was to investigate the changes in gingival dimensions and root coverage using the same surgical procedure but varying the amount of the connective tissue graft left uncovered. METHODS: Twenty-five Class I or II recession defects in 20 healthy subjects were randomly assigned to test (exposed connective tissue group; E group) or control (fully covered connective tissue group; FC group) groups and treated with a connective tissue graft procedure. In the E group, 1 to 2 mm of the graft was left uncovered at the completion of the surgery, whereas the FC group had the graft completely covered by the flap. Clinical parameters assessed included probing depth, recession depth, clinical attachment level, width of keratinized tissue, mobility, and plaque score. RESULTS: At 12 weeks, the mean root coverage percentages for FC and E groups were 93% and 88%, respectively. The difference between the groups was not statistically significant (P=0.48). Complete root coverage was observed in 79% and 64% of the subjects in FC and E groups, respectively. There was greater increase in the width of keratinized tissue in the E group (1.5+/-1.1 mm) than the FC group (0.9+/-0.9 mm), although this difference did not reach statistical significance (P=0.16). There were no statistically significant differences between the groups for the changes in other parameters. CONCLUSIONS: Both procedures resulted in successful root coverage with an increase in the width of keratinized tissue. Leaving a portion of the graft exposed resulted in a greater increase of keratinized tissue, and complete coverage of the graft resulted in greater root coverage. However, these differences did not reach statistical significance.

Periodontal assessment by right- and left-handed examiners: is there a difference?

BACKGROUND: Multiple factors that influence the precision of periodontal probing measurements have been identified. These factors can be categorized as being dependent upon host-related, probe-related, or examiner-related variables. However, the potential influence of examiner handedness (right or left) on the measurement of periodontal probing depths (PDs) has not been addressed. The purpose of this study was to determine whether the measurements of PDs in the right and left quadrants are influenced by the handedness of the examiner. METHODS: Eight systemically healthy adult subjects with varying degrees of attachment loss and a minimum of 20 teeth were examined by five right-handed and five left-handed clinicians. The 10 clinicians were trained and calibrated for reproducible probe placement and angulation. PDs were measured using a conventional periodontal probe at six sites per tooth. Mean PD measurements were compared between right- and left-handed examiners using analysis of variance (ANOVA) with a random patient effect to correlate participant data and a random effect for the examiner. RESULTS: There was no statistical difference in the measurement of PDs between right- and left-handed examiners at various locations in the mouth (P>0.17 in all cases). Only three individual sites showed a statistically significantly different mean PD between right- and left-handed examiners (unadjusted P<0.05; differences at or near 0.5 mm). Overall, right-handed examiners tended to record slightly higher PD measurements than left-handed examiners, but this difference did not reach statistical significance. CONCLUSIONS: The handedness of the periodontal examiner does not appear to influence the recorded measurement of probing depths. This finding is relevant to those conducting clinical research involving assessment of periodontal status.

Resistance of fluorescent-labelled Actinobacillus actinomycetemcomitans strains to phagocytosis and killing by human neutrophils.

Neutrophils are initially the predominant cells involved in the host defence of bacterial infections, including periodontal disease. Aggressive periodontitis is associated with Actinobacillus actinomycetemcomitans, a Gram-negative capnophilic microorganism. Infections caused by A. actinomycetemcomitans are not resolved by the host immune response despite the accumulation of neutrophils at the site of inflammation. To better understand the role of natural host defence mechanisms in A. actinomycetemcomitans infections, the interaction of phenotypically diverse strains of this pathogen with human neutrophils was assessed directly using techniques such as genetic labelling with the gene for green fluorescent protein, fluorescence-activated cell sorting and fluorescence imaging. The study included clinical isolates of A. actinomycetemcomitans represented by self-aggregating, biofilm-associated and isogenic planktonic variants. Data obtained showed that complement-mediated phagocytosis of A. actinomycetemcomitans was generally inefficient regardless of strain-specific serotype or leukotoxin production. Furthermore, the majority of ingested bacteria remained viable after exposure to neutrophils for 1 h. Interestingly, uptake of antibody-opsonized bacteria resulted in the rapid cell death of neutrophils. This was in contrast to ingestion of complement-opsonized bacteria, which did not affect neutrophil viability. The methods used in this study provided reliable and reproducible results with respect to adherence, phagocytosis and killing of A. actinomycetemcomitans when encountering human neutrophils.

Pharmacodynamic and pharmacokinetic effects in gingival crevicular fluid from re-dosing during brushing.

The IntelliClean System from Sonicare and Crest combines a rechargeable sonic power toothbrush and a novel liquid toothpaste into one integrated system, providing the opportunity to re-dose with toothpaste during the brushing cycle. The purpose of this study was to investigate cleaning effects from in-mouth re-dosing with toothpaste during the brushing cycle vs conventional bolus dosing. This was a randomized, examiner-blind, six-period, crossover clinical study. Eighteen adult subjects used an experimental integrated system employing either a re-dosing regimen (2 doses at the start of brushing with 1 additional in-mouth dose during the last 30 seconds of brushing [2+1]) or a conventional regimen (2 doses at the start of brushing only [2+0]). Gingival crevicular fluid (GCF) was sampled at the final brushing quadrant from a preselected site in the gingival sulcus using filter strips at baseline and at 4, 15, and 120 minutes postbrushing. Mean change from baseline in the concentrations of total facultative anaerobes (TFAs) and gram-negative anaerobes (GNAs) in the GCF at 120 minutes posttreatment were modeled separately using general linear mixed models. Area under the curve of surfactant (sodium dodecyl sulfate [SDS]) in GCF over 2 hours postbrushing was calculated and modeled using an analysis of variance model. All hypotheses were tested 2-sided at the 5% significance level. Relative to the conventional regimen, the re-dosing (2+1) regimen produced a significantly greater reduction in log10 (TFA colony-forming units [CFU]/microL GCF) after brushing, 0.99+/-0.12 vs 0.65+/-0.12 (mean change +/- standard error), and a significantly greater reduction in log10 (GNA CFU/microL GCF) after brushing, 0.75 +/-0.14 vs 0.45 +/- 0.14. The re-dosing regimen led to significantly more SDS in GCF relative to the conventional regimen over the 2-hour time period. Re-dosing of liquid toothpaste during the brushing cycle with the IntelliClean System leads to a significantly increased cleaning effect, as defined by a reduced bacterial count in GCF, and significantly higher levels of surfactant in the GCF up to 2 hours after the brushing event.

Partial-mouth assessment of periodontal disease in an adult population of the United States.

BACKGROUND: It has been previously demonstrated, using periodontal data from an untreated population, that half-mouth assessment of six sites/tooth provides an appropriate alternative to whole-mouth assessment of periodontal disease status. Since periodontal destruction exhibits left-right symmetry, it was hypothesized that this would be equally applicable to a population with access to routine dental care. METHODS: Adult subjects (N = 92) with a range of disease levels participated in the study. Probing depths (PDs) and recession (REC) were measured directly on six sites/tooth, on all teeth (excluding third molars), and clinical attachment levels (CALs) were derived. Partial-mouth assessments, i.e., assessment of limited sites and/or teeth, were compared with whole-mouth assessment as follows. Intraclass correlation coefficients (ICCs) were calculated for mean PD, CAL, and REC, and for percentage of sites with disease above a specified threshold, to determine the agreement between the whole- and partial-mouth assessment. The sensitivity of partial-mouth assessment of disease prevalence also was determined. RESULTS: For assessment of six sites per tooth in one upper and one lower quadrant, ICCs were consistently >0.80. Assessment of two sites per tooth or only Ramfjord teeth generally underestimated disease extent and severity, and prevalence, compared to half-mouth assessment. CONCLUSIONS: These results support the use of a half-mouth examination of six sites/tooth, to conserve time, limit cost, and reduce patient and examiner fatigue, while providing maximal clinical information. Assessment of only two sites per tooth or the Ramfjord teeth was not suitable for evaluation of either disease extent and severity or prevalence.

The effect of shared genetic and environmental factors on periodontal disease parameters in untreated adult siblings in Guatemala.

BACKGROUND: Increasing evidence supports the role of genetic factors in susceptibility to infectious diseases, including chronic periodontitis. The role of genetic factors in phenotypic expression can be estimated from the degree of resemblance between relatives, as compared with that of unrelated members of a population. Heritability is an estimate of the proportion of total phenotypic variation of a quantitative trait, which is attributable to genetic factors, and is based on the variance within versus between family members. The aim of this study was to determine whether there is a familial basis for periodontal disease status in an untreated population in Guatemala using heritability estimates as a measure of familial clustering of disease. METHODS: One-hundred and thirteen adult subjects (including both siblings and spouse pairs), age range 35 to 60 years, participated in this study. Full-mouth periodontal examinations were performed and heritability estimates were calculated for mean plaque score, mean gingival index (GI), probing depth (PD), and clinical attachment level (CAL). Intraclass correlation coefficients (ICCs) were calculated using the same parameters for spouses to determine whether a common family environment in adulthood plays a role in disease expression. RESULTS: Only in the case of mean plaque score and mean recession score were heritability estimates significantly above zero at alpha = 0.05. For spouse pairs, mean GI score, mean PD, and percentage of sites of PD > or = 5 mm showed a statistically significant ICC. CONCLUSIONS: These results lead us to reject the hypothesis that there is substantial heritability for periodontal disease expression in this population. This may be due to an underlying lack of genetic variation within this sample or may indicate that, compared with the role of environmental factors, the genetic contribution to periodontal disease phenotypes is relatively minor.

The applicability of half-mouth examination to periodontal disease assessment in untreated adult populations.

BACKGROUND: Data from whole-mouth examinations are the gold standard for accurate assessment of periodontal disease. Since periodontal destruction exhibits left-right symmetry, however, it is hypothesized that a half-mouth exam provides an appropriate alternative to whole-mouth assessment, with considerable advantage over a more limited partial-mouth assessment of index teeth. METHODS: Data from 2 untreated populations were utilized in the analyses. Half-mouth (random diagonal quadrants) and Ramfjord teeth assessment was compared with whole-mouth assessment as follows. Intraclass correlation coefficients (ICCs) were calculated for mean plaque index (PI), gingival index (GI), probing depth (PD), and clinical attachment level (CAL) and for percentage of sites with PD > or = 4, 5, or 6 mm; CAL > or = 3, 4, 5, or 6 mm; and recession > or = 3 mm to determine the agreement between the whole- and partial-mouth assessment. Disease prevalence was also determined for both whole- and partial-mouth assessments. RESULTS: For mean PI, GI, PD, and CAL, both half-mouth and Ramfjord teeth assessment provided an acceptable alternative to whole-mouth assessment (ICCs > 0.92). For percentage of sites above a specified threshold, ICCs were generally greater than 0.90 in all age cohorts for half-mouth assessment, but consistently lower for Ramfjord teeth assessment. Ramfjord teeth assessment also considerably underestimated disease prevalence compared with half-mouth assessment. CONCLUSIONS: These results support the use of a half-mouth examination procedure, to conserve time, limit cost, and reduce patient and examiner fatigue while providing maximal clinical information. Ramfjord teeth assessment was not as suitable for evaluation of either disease extent or prevalence.