The Association Between Cumulative Periodontal Disease and Stroke History in Older Adults

BACKGROUND

Since the late 1980s, several studies have been conducted to investigate the relationship between periodontal disease and ischemic stroke. The purpose of this study is to investigate the relationship of periodontal disease to the self-reported history of stroke in the elderly (60 years of age and older) by examining the data of the Third National Health and Nutrition Examination Survey (NHANES III).

METHODS

Data from NHANES III, a large population-based cross-sectional survey of the United States, were used for this study. Because 1,563 of the 5,123 subjects in the study were edentulous, and periodontal disease is a major cause of tooth loss, it was necessary to account for edentulousness in the statistical analysis to avoid bias. Hence, a new index called the periodontal health status (PHS) index was developed to address this problem. Two measures of PHS were developed: PHS I, based on the median percentage of sites with >/=2 mm clinical attachment loss (CAL), and PHS II, based on the median percentage of sites with >/=3 mm CAL. Multiple logistic regression analysis was used to test for the association of PHS with stroke history. Two types of a multiple logistic regression model were fit: 1) logistic regression modeling with adjustment for age and tobacco use only; and 2) logistic regression modeling with adjustment of all statistically significant confounders.

RESULTS

Based on multiple logistic regression analysis of PHS with adjustment for age and tobacco use only, completely edentulous elderly adults (PHS Class 5) and partially edentulous (teeth in one arch) elderly adults with appreciable clinical attachment loss (PHS Class 4) were significantly more likely to have a history of stroke compared to dentate adults (teeth in both arches) without appreciable clinical attachment loss (PHS Class 1). When multiple logistic regression models were fit with adjustment of all significant confounders, no statistically significant association was found between PHS and stroke.

CONCLUSIONS

Based on the results of this study, there is evidence of an association between cumulative periodontal disease, based on PHS, and a history of stroke. However, it is unclear whether cumulative periodontal disease is an independent risk factor for stroke or a risk marker for the disease.

Risk of tooth loss after cigarette smoking cessation

INTRODUCTION

Little is known about the effect of cigarette smoking cessation on risk of tooth loss. We examined how risk of tooth loss changed with longer periods of smoking abstinence in a prospective study of oral health in men.

METHODS

Research subjects were 789 men who participated in the Veterans Administration Dental Longitudinal Study from 1968 to 2004. Tooth status and smoking status were determined at examinations performed every 3 years, for a maximum follow-up time of 35 years. Risk of tooth loss subsequent to smoking cessation was assessed sequentially at 1-year intervals with multivariate proportional hazards regression models. Men who never smoked cigarettes, cigars, or pipes formed the reference group. Hazard ratios were adjusted for age, education, total pack-years of cigarette exposure, frequency of brushing, and use of floss.

RESULTS

The hazard ratio for tooth loss was 2.1 (95% confidence interval [CI], 1.5-3.1) among men who smoked cigarettes during all or part of follow-up. Risk of tooth loss among men who quit smoking declined as time after smoking cessation increased, from 2.0 (95% CI, 1.4-2.9) after 1 year of abstinence to 1.0 (95% CI, 0.5-2.2) after 15 years of abstinence. The risk remained significantly elevated for the first 9 years of abstinence but eventually dropped to the level of men who never smoked after 13 or more years.

CONCLUSION

These results indicate that smoking cessation is beneficial for tooth retention, but long-term abstinence is required to reduce the risk to the level of people who have never smoked.

Compliance as a prognostic indicator: retrospective study of 505 patients treated and maintained for 15 years

BACKGROUND

The relationship of patient compliance to overall tooth prognosis remains controversial. There are little data, often conflicting, that pertain to tooth loss as a function of patient compliance.

METHODS

This retrospective study evaluates the impact of compliance (complete versus erratic) on common periodontal clinical variables, such as probing depth, bleeding index, plaque index, and tooth loss for 505 patients in a long-term period of observation (15 to 23 years) and maintenance therapy (at least 10 years). Compliance was defined in two ways for all analyses. Under the definition for compliance 1, patients who missed <30% of all prescribed maintenance visits were classified as complete compliers. Under the definition for compliance 2, patients who never went 2 years without a maintenance visit were classified as complete compliers. Change in clinical variables was dichotomized into reduction in plaque index versus no reduction, reduction in bleeding on probing versus no reduction, reduction in the percentage of periodontal pockets>3 mm versus no reduction, no increase in decayed, missing, or filled teeth (DMFT) versus increase, and no tooth loss versus tooth loss. The effects of both definitions of compliance were then evaluated in a series of multiple logistic regression models with adjustment for potential confounders.

RESULTS

The analysis of the dichotomous change in clinical parameters over time revealed that complete compliers tended to show reduction in bleeding on probing and reduction in plaque index compared to erratic compliers for both definitions of compliance. In contrast, complete compliers under compliance 2 were less likely to have a reduction in the percentage of periodontal pockets >3 mm compared to erratic compliers, whereas complete compliers under compliance 1 had about the same likelihood of demonstrating a reduction in periodontal pockets compared to erratic compliers under this classification scheme. Under both definitions for compliance, complete compliers were more likely to exhibit tooth loss than erratic compliers, with the greatest tooth loss exhibited by complete compliers under the definition for compliance 1.

CONCLUSIONS

Based on these results, complete compliers under both definitions tended to show a reduction in plaque and bleeding on probing over time. However, change in periodontal pockets and DMFT over time varied according to the definition of compliance that was used. In addition, the results seem to indicate that the decision for tooth extraction made by dental health professionals at maintenance visits may result in greater tooth loss.

Grindability of cast Ti–Hf alloys

As part of our systematic studies characterizing the properties of titanium alloys, we investigated the grindability of a series of cast Ti-Hf alloys. Alloy buttons with hafnium concentrations up to 40 mass% were made using an argon-arc melting furnace. Each button was cast into a magnesia-based mold using a dental titanium casting machine; three specimens were made for each metal. Prior to testing, the hardened surface layer was removed. The specimens were ground at five different speeds for 1 min at 0.98 N using a carborundum wheel on an electric dental handpiece. Grindability was evaluated as the volume of metal removed per minute (grinding rate) and the volume ratio of metal removed compared to the wheel material lost (grinding ratio). The data were analyzed using ANOVA. A trend of increasing grindability was found with increasing amounts of hafnium, although there was no statistical difference in the grindability with increasing hafnium contents. We also found that hafnium may be used to harden or strengthen titanium without deteriorating the grindability.

Psychological profile in oral lichen planus

AIM

Oral lichen planus (OLP) is an oral lesion with an enigmatic etiology. To explore the possibility of psycho-somatization, we evaluated the psychological personality profiles of OLP patients.

METHODS

Twenty patients with reticular; 20 with erosive form of OLP, and 25 controls were tested with the psychological Minnesota Multiphasic Personality Inventory (MMPI)-202 test. Eight clinical scales (hypochondriasis, depression, hysteria, psychopathic deviate, paranoia, psychasthenia, schizophrenia, and hypomania) as well as cortisol level, CD3, CD4, CD8, and CD16 markers by group were compared. Psychosomatization was evaluated by the use of internalization ratio (IR) Index.

RESULTS

A characteristic MMPI profile was noted in the OLP groups with high IR index value. Significant differences among the groups were detected for cortisol, CD4, CD8, and CD16 counts. Mean values for hypochondriasis, depression, and hysteria were all significantly different with significantly higher mean scores for both reticular and erosive OLP subjects compared with controls.

CONCLUSIONS

Prolonged emotive stress in many OLP patients may lead to psychosomatization and may contribute to the initiation and clinical expression of this oral disorder.

CLINICAL SIGNIFICANCE

If additional research involving a larger and more diverse sample of patients confirms these findings, clinical trials will be needed to determine whether adjunctive psychological intervention provides a benefit in treating patients with OLP.

Evaluation of the safety and efficacy of periodontal applications of a living tissue-engineered human fibroblast-derived dermal substitute. I. Comparison to the gingival autograft: a randomized controlled pilot study

BACKGROUND

Periodontists have found the gingival autograft to be an effective and predictable technique to increase the amount of attached gingiva around teeth, but this technique requires the surgeon to harvest donor tissue from a remote surgical site. The present study seeks to evaluate the safety and effectiveness of a tissue-engineered skin equivalent, a living human fibroblast-derived dermal substitute (HF-DDS), compared to a gingival autograft (GA) consisting of donor tissue harvested from the patient's palate in a procedure designed to increase the amount of keratinized tissue around teeth that do not require root coverage.

METHODS

Twenty-five patients with insufficient attached gingiva associated with at least two teeth in contralateral quadrants of the same jaw were treated. One tooth in each patient was randomized to receive either a GA (control) or a HF-DDS graft (test). Clinical parameters measured at baseline and 3, 5, 7, 9, and 12 months included recession, clinical attachment level, keratinized tissue height, and plaque index. Probing depth was measured at 7, 9, and 12 months. Inflammation of each site was scored and texture and color of the grafted tissue were compared to the surrounding tissue. Resistance to muscle pull was evaluated and a questionnaire was used to determine patient preference. Surgical position of the graft and alveolar bone level were recorded at the surgical visit and patients were evaluated weekly for the first 4 weeks at which time recession and level of oral hygiene were measured. Biopsies and persistence studies were performed on a subset of the patients.

RESULTS

Results for both test and control groups were similar for all measured clinical parameters with the exception of amount of keratinized tissue and percent shrinkage of keratinized tissue. The control group exhibited an average of 1.0 to 1.2 mm more keratinized tissue over time than the test group (P <0.001) and the control group had about half as much shrinkage as the test group over time (P <0.001). Test sites demonstrated significantly better color match over time compared to control sites. Similarly, tissue texture for test sites was significantly better than control sites over time.

CONCLUSIONS

Based on the results of this investigation, the tissue engineered HF-DDS graft was safe and capable of generating keratinized tissue without the morbidity and potential clinical difficulties associated with donor site surgery. The GA generated more keratinized tissue and shrank less than the HF-DDS graft, but the test graft generated tissue that appeared more natural.

Evaluation of the Safety and Efficacy of Periodontal Applications of a Living Tissue-Engineered Human Fibroblast- Derived Dermal Substitute. II. Comparison to the Subepithelial Connective Tissue Graft: A Randomized Controlled Feasibility Study

BACKGROUND

The subepithelial connective tissue graft, traditionally harvested from the patient's palate, is commonly used for root coverage in periodontal recession defects. This study evaluates the safety and effectiveness of a living human fibroblast-derived dermal substitute (HF-DDS) compared to a connective tissue graft (CTG) for root coverage in these situations.

METHODS

Thirteen patients were selected for this study. Each patient had Miller Class I or II bilateral facial recession defects > or =3 mm on two non-adjacent teeth. The test tooth received an HF-DDS graft, while a CTG was placed on the control site. The 10 test surgeries were performed by one operator and three pilot surgeries were performed by another surgeon. Eight of the HF-DDS sites received a single thickness of material; five received a double thickness. Clinical measurements were taken at baseline; 1 week; and 1, 3, and 6 months following surgery. Parameters measured were plaque index, recession depth, clinical attachment levels, recession width, probing depth, and width of keratinized tissue. All clinical readings were taken by a masked, calibrated examiner.

RESULTS

There were no statistically significant differences between the test and control groups. The amount of root coverage was slightly greater for the control group than for the test group, but statistically the difference was insignificant. The width of the recession defect measured at the cemento-enamel junction (CEJ) for the test group was slightly smaller than that of the control group at the conclusion of the study. The amount of keratinized tissue was the same in both groups at 6 months. The probing depth was slightly greater in the control group as was the gain in clinical attachment, but neither was statistically significant. The amount of root coverage obtained when one layer of HF-DDS was used compared to the amount of coverage obtained when two layers were used approached statistical significance, but the small sample size may have been responsible for the difference.

CONCLUSION

Within the limits of this study, the human fibroblast-derived dermal substitute may offer potential as a substitute to the connective tissue graft for covering areas of facial Miller Class I or Class II gingival recession in humans.

Assessment of SS-A and SS-B in parotid saliva of patients with Sjogren's syndrome

BACKGROUND

The purpose of this study was to compare the sensitivity of parotid saliva to that of serum in detecting anti-SSA/Ro and anti-SSB/La autoantibodies in patients with Sjögren's syndrome.

METHODS

Forty patients and 20 controls participated in the study; all patients met the 1993 European Community criteria for the diagnosis of Sjögren's syndrome. Healthy controls were age- and sex-matched individuals with no signs or symptoms of Sjögren's syndrome. Serum and saliva samples were evaluated using AffiniTech SSA/Ro and SSB/La antibodies kits (AffiniTech, Ltd. Bentonville, AR, USA). The results were also compared with serological status of SS-A and SS-B as reported by an independent clinical laboratory.

RESULTS

Serum was significantly more sensitive than saliva in detecting SSA/Ro and SSB/La antibodies (P = 0.001). There was high agreement between the results with the AffiniTech kits and the independent laboratory (kappa = 0.80; P < 0.001). However, there was poor agreement between saliva and serum results (kappa = 0.174; P = 0.168).

CONCLUSIONS

The overall results appear to support that serum analysis is effective method for evaluating the presence of SS-A and SS-B autoantibodies.

Prospective Assessment of the Use of Enamel Matrix Proteins With Minimally Invasive Surgery

BACKGROUND

Minimally invasive surgery (MIS) is a surgical technique using very small incisions, indicated for performing regenerative therapy in periodontal defects. Enamel matrix proteins (EMP) have been shown to enhance periodontal regeneration. This study was undertaken to determine the effect of using EMP in combination with an MIS approach.

METHODS

Patients from two private periodontal practices with chronic periodontitis who, following non-surgical therapy, had one or more sites with probing depths (PD) of > or =6 mm were included in the study. An MIS approach was utilized for surgical access. Following surgical debridement, EMP was placed into the bony defect. The surgical sites were reevaluated after at least 11 months.

RESULTS

Surgical treatment was performed at 160 sites in 16 patients. No significant differences were noted in the results between the two offices and the data were combined. Mean PD reduction (P = 0.002) and attachment level improvements (P = 0.012) were significantly greater than 3 mm with mean post-surgical PD of 3.17 mm and attachment levels of 4.05 mm, based on subject means. Mean change in recession following surgery was negligible (0.01 mm). All sites were considered to be clinically successful.

CONCLUSION

The combination of MIS and EMP yields significant reductions in probing depths and improvements in attachment levels while producing little or no increase in recession.

Stain reduction of an integrated oral hygiene system

This article discusses research to determine the efficacy of a prototype integrated power toothbrush and toothpaste dispensing system, the IntelliClean System from Sonicare and Crest, in the removal of extrinsic stain. The prototype integrated system and a positive control, the Sonicare Elite with conventional toothpaste, were evaluated in 2 randomized, single-blinded, parallel 4-week controlled clinical trials. There was a low dropout rate, with 28 subjects of the 31 randomized in study 1 completing the study (10% loss to follow-up) and 26 subjects of the 28 randomized in study 2 completing the study (7% loss to follow-up). Lobene stain scores were used to assess the extent and intensity of stain for all teeth meeting the criteria for inclusion in the studies. Lobene stain scores were assessed at baseline and after 4 weeks in both studies. A survey also was conducted at the conclusion of each study to determine user attitude toward the integrated system. The prototype integrated system was found to significantly reduce overall extrinsic stain over time, performing not significantly differently from the positive control. Overall, the prototype integrated system reduced the composite measure of stain that encompasses both the extent and intensity of stain by 60%. This research demonstrates that the IntelliClean System from Sonicare and Crest is highly effective in reducing extrinsic stain.

Plaque reduction over time of an integrated oral hygiene system

This article compares the efficacy of a prototype integrated system (the IntelliClean System from Sonicare and Crest) in the reduction of supragingival plaque to that of a manual toothbrush and conventional toothpaste. The integrated system was compared to a manual toothbrush with conventional toothpaste in a randomized, single-blinded, parallel, 4-week, controlled clinical trial with 100 subjects randomized to each treatment group. There was a low dropout rate, with 89 subjects in the manual toothbrush group (11% loss to follow-up) and 93 subjects in the integrated system group (7% loss to follow-up) completing the study. The Turesky modification of the Quigley and Hein Plaque Index was used to assess full-mouth plaque scores for each subject. Prebrushing plaque scores were obtained at baseline and at 4 weeks after 14 to 20 hours of plaque accumulation. A survey also was conducted at the conclusion of the study to determine the attitude toward the two oral hygiene systems. The integrated system was found to significantly reduce overall and interproximal prebrushing plaque scores over 4 weeks, both by 8.6%, demonstrating statistically significant superiority in overall plaque reduction (P = .002) and interproximal plaque reduction (P < .001) compared to the manual toothbrush with conventional toothpaste, which showed no significant reduction in either overall plaque or interproximal plaque. This study demonstrates that the IntelliClean System from Sonicare and Crest is superior to a manual toothbrush with conventional toothpaste in reducing overall plaque and interproximal plaque over time.

Osseointegration of dental implants complexed with rhBMP-2: a comparative histomorphometric and radiographic evaluation

PURPOSE

To evaluate the effect of rhBMP-2 on implant osseointegration using histomorphometric and radiographic imaging analyses and determine the diagnostic accuracy of periapical radiographs regarding clinical bone-implant contact levels.

MATERIALS AND METHODS

Hollow-cylinder implants were filled with an absorbable collagen sponge soaked with recombinant human bone morphogenetic protein-2 (rhBMP-2) or left empty and implanted in the mandibles of dogs. Animals were followed for 2, 4, 8, or 12 weeks. At the end of each time interval, the animals were sacrificed and specimens were collected for histomorphometric and radiographic evaluation of the bone-implant contact levels.

RESULTS

Both groups exhibited the same mean histologic bone-implant contact on the outer surface of the implant, except for the 4-week group. The radiographic evaluation of bone-implant contact overestimated the actual osseointegration levels by at least 30%, a significant amount.

DISCUSSION

The osteoinductive and regenerative potential of rhBMP-2 is of clinical benefit in cases where bone augmentation is indicated and improved levels of osseointegration are expected. Radiographic evaluation has been the most widely employed technique in clinical practice for assessing bone levels around dental implants and comparing changes over time. However, there is a limit to the diagnostic accuracy of conventional radiographs when compared to the data obtained by histologic analysis.

CONCLUSION

Application of rhBMP-2 within the confined boundaries of the hollow chamber of the implant had a limited effect on the osseointegration level along its outer surface, perhaps because of physically restricted diffusion. Radiographic evaluation resulted in the overestimation of bone-implant contact, and poor correlation with the histomorphometric data was found.

A Comparative Study of Coronally Advanced Flaps With and Without the Addition of Enamel Matrix Derivative in the Treatment of Marginal Tissue Recession

BACKGROUND

The primary aim of this randomized, controlled, clinical investigation was to evaluate the differences in clinical parameters of root coverage procedures utilizing coronally advanced flaps (CAF) with and without enamel matrix derivative (EMD). Another aim was to evaluate if EMD can influence keratinization of tissues utilizing these procedures.

METHODS

Fifty-eight contralateral sites in 17 patients with > or = 2 mm of Miller Class I, II, and III buccal marginal tissue recession were treated. Test sites received CAF plus EMD while control sites were treated with CAF only, with each patient serving as his own control. Patients were followed for 3 and 6 months. All data were analyzed using the method of generalized estimating equations. A P value <0.05 was considered significant (alpha = 0.05).

RESULTS

There was a mean increase in keratinized tissue of 0.60 mm for test sites and a mean decrease of 0.05 mm for control sites. Test sites demonstrated significantly better root coverage (P<0.001), 89.7% and 92.9% root coverage after 3 months and 6 months, respectively, while control sites had 56.6% and 66.8% root coverage after 3 months and 6 months, respectively. There was significantly more root coverage among test sites compared to control sites, regardless of arch or Miller classification.

CONCLUSIONS

Based on the results of this study, the application of enamel matrix derivative to denuded root surfaces receiving coronally advanced flaps significantly increased the percentage of root coverage compared to CAF without EMD. In addition, EMD application was accompanied by a significant increase in keratinized tissue 6 months after surgery.

Statherin is an in vivo pellicle constituent: identification and immuno-quantification

Recently, we demonstrated that anti-statherin monoclonal antibodies could be generated upon immunisation of mice with in vivo formed human acquired enamel pellicle, indicating that statherin is a constituent of pellicle. To gain insight in the in vivo adsorption behaviour of statherin we tested the abundance of statherin in pellicle and investigated the relationship between statherin and protein levels in salivary secretions and pellicle using a capture ELISA. Statherin levels were approximately 20-fold higher in parotid and submandibular-sublingual secretions than in cleared whole saliva supernatant or pellicle, suggesting the rapid degradation of statherin in the oral cavity. A strong positive correlation was observed between statherin and protein levels in pellicle but not in saliva indicating that statherin and protein adsorption to pellicle are related processes. This indicates that statherin represents the integral part of proteins that constitute the pellicle structure and may play a key role in its formation.

A Method to Enhance Determining the Clinical Relevance of Periodontal Research Data: Number Needed to Treat (NNT)

It would be advantageous if clinical trials reported both statistical and clinically meaningful results. In this regard, determination of the number of sites that would need to be treated in a test group to provide a beneficial result or prevent an adverse event at one additional site beyond the control group would provide useful information. This editorial addresses the use of NNT (number needed to treat) calculations to enhance determining the clinical relevance of periodontal research findings. The application, requirements for use, benefits, and limitations of employing NNT calculations are discussed.

The Effect of Occlusal Discrepancies on Gingival Width

BACKGROUND

A relationship between occlusal forces and gingival recession has been postulated in the past. However, minimal data are available to demonstrate a causal relationship between occlusal forces and recession.

METHODS

The records from a private practice limited to periodontics were reviewed to find patients who had complete periodontal examination records, including occlusal analysis and gingival width, that were recorded at least 1 year apart. Patients who fit this criteria were divided into those who had none of the recommended treatment (untreated, n = 30), those who had only non-surgical treatment (partially treated, n = 20), and a control group who had completed all recommended surgical and non-surgical treatment (completely treated, n = 41). The data for each tooth of each patient, including occlusal status and gingival width, were placed in a database and analyzed for a relationship between occlusal discrepancies and changes in gingival width.

RESULTS

No statistically significant relationship was detected between the presence of occlusal discrepancies and initial width of the gingival tissue (P = 0.414) or between occlusal treatment and changes in the width of the gingiva (P = 0.481).

CONCLUSION

Based on the current study, there does not appear to be a relationship between occlusal discrepancies and gingival recession.

Patient preference for ultrasonic or hand instruments in periodontal maintenance

The purpose of this study was to determine if patients prefer ultrasonic or hand instruments for periodontal maintenance. A questionnaire of 13 items was answered by 469 patients in three periodontal offices. The results showed a strong preference (74%) for ultrasonic instruments. The possibility of increased compliance because of this preference is discussed.

Crown lengthening in mandibular molars: a 5-year retrospective radiographic analysis

BACKGROUND

Crown lengthening procedures are a significant part of the periodontist's armamentarium. In order to recreate the clinical space lost to caries or trauma necessary for prosthetic restoration, osseous surgery is often required. If the procedure is not carefully planned, it may result in furcation involvement of multirooted teeth.

METHODS

Twenty-six subjects with 26 mandibular molar teeth requiring crown lengthening procedures prior to prosthetic crown placement were evaluated. Nineteen subjects with 24 prosthetic crowns on lower molars which had not undergone crown lengthening were included as control teeth. Bite-wing radiographs prior to surgery (for the test group) or placement of the crown (control group) and 5 years after completion of the prosthesis were compared and analyzed.

RESULTS

Of the 26 test teeth, 10 teeth (38.5%) were found to have radiographic evidence of furcation involvement, whereas none of the control teeth developed furcation invasions.

CONCLUSION

A critical distance from the furcation (CDF) of 4 mm was established as a landmark under which, if surgery was performed on mandibular molars, chances of furcation involvement in the future were very high.

A national survey of the oral health status of homeless veterans

OBJECTIVES

This study reports results from a survey designed to (1) assess the oral health needs of a national sample of homeless veterans and (2) compare the dental needs of homeless veterans participating in VA-sponsored rehabilitation programs with domiciled veterans in VA substance addiction programs.

METHODS

Homeless veterans enrolled in a nationwide rehabilitation program (n = 1,152) completed a survey including questions concerning patients' perceptions of their oral health, dental service needs and use, and alcohol and tobacco use. A sample of these veterans (n = 281) subsequently received dental exams. A comparison group of domiciled veterans enrolled in VA substance abuse programs (n = 339) completed a similar survey. A sample of these veterans (n = 150) also received dental exams.

RESULTS

Sociodemographic variables, patient-reported oral health information and risk behaviors, and findings from dental exams described two remarkably similar populations.

CONCLUSIONS

As expected, the homeless veterans exhibited poor oral health, but it was not different from domiciled veterans enrolled in substance addiction programs. Lifestyle choices, such as heavy drinking and smoking, may contribute more to poor oral health than living conditions.

The prevalence of periodontal-related changes in adolescents with asthma: results of the Third Annual National Health and Nutrition Examination Survey

PURPOSE

The purpose of this study was to explore the association between asthma and periodontal disease in adolescents using oral examination and health interview data from the Third National Health and Nutrition Examination Survey (NHANES III) 1988-1994.

METHODS

The study population comprised 1,596 adolescents 13 to 17 years of age: 253 (16%) asthmatics and 1,358 (84%) nonasthmatic controls who were examined for bleeding on probing (BOP), subgingival calculus (SBC), supragingival calculus (SPC), probing depth greater than or equal to 3 mm (PD), and loss of periodontal attachment greater than or equal to 2 mm (LPA). The authors fitted separate multivariate GEE Poisson regression models adjusting for parents' income, gender, race, exposure to potentially xerogenic drugs (antihistamines, corticosteroids, and inhalers), tobacco exposure, and dental examination within the past year.

RESULTS

None of the periodontal measures was associated with asthma severity or with the use of antiasthmatic drugs. However, several covariates had statistically significant odds ratios (P < .05).

CONCLUSIONS

There was no evidence to support the association between asthma and periodontal health in the adolescent population. Since the findings may be due to the inherent limitations of cross-sectional studies, the lack of knowledge about the daily dose of antiasthmatic medication, and the level of-compliance with the therapeutic regimen, future studies should be longitudinal and monitor medication use.

Increased preventive practices lead to greater tooth retention

Prior research has rarely examined the impact of ADA-recommended preventive practices on tooth retention. We hypothesized that better oral hygiene leads to increased tooth retention. We examined the association of cross-sectional and long-term assessments of preventive practices, as well as various combinations of hygiene practices, with tooth retention. Among 736 male participants in the VA Dental Longitudinal Study, we utilized cross-sectional and longitudinal self-reports of toothbrushing, dental floss use, annual prophylaxis, and combinations of such behaviors, and examined their association with clinically assessed numbers of teeth. Baseline and long-term hygiene behaviors (except brushing) were associated with an increased baseline number of teeth and decreased subsequent tooth loss. Use of multiple hygiene behaviors was associated with greater tooth retention, cross-sectionally and longitudinally. Adherence to ADA recommendations for preventive care leads to better oral health, and consistently practicing preventive behaviors over the long term confers greater benefits than doing so over the short term.

Electrochemical characterization of cast titanium alloys

A reaction layer forms on cast titanium alloy surfaces due to the reaction of the molten metal with the investment. This surface layer may affect the corrosion of the alloy in the oral environment. The objective of this study was to characterize the in vitro corrosion behavior of cast titanium alloys. ASTM Grade 2 CP titanium, Ti-6Al-4V, Ti-6Al-7Nb and Ti-13Nb-13Zr alloys were cast into a MgO-based investment. Experiments were performed on castings (N=4) with three surface conditions: (A) as-cast surface after sandblasting, (B) polished surface after removal of the reaction layer, and (C) sandblasted surface after removal of the reaction layer. Open-circuit potential (OCP) measurement, linear polarization, and potentiodynamic cathodic polarization were performed in aerated (air+10% CO(2)) modified Tani-Zucchi synthetic saliva at 37 degrees C. Potentiodynamic anodic polarization was subsequently conducted in the same medium deaerated with N(2)+10% CO(2) gas 2 h before and during the experiment. Polarization resistance (R(P)) and corrosion rate (I(CORR)) were calculated. Numerical results were subjected to nonparametric statistical analysis at alpha=0.05. The OCP stabilized for all the specimens after 6 x 10(4)s. Apparent differences in anodic polarization were observed among the different surfaces for all the metals. A passivation region followed by breakdown and repassivation were seen on specimens with surfaces A and C. An extensive passive region was observed on all the metals with surface B. The Kruskal-Wallis test showed no significant differences in OCP, R(p), I(CORR) or break down potential for each of the three surfaces among all the metals. The Mann-Whitney test showed significantly lower R(P) and higher I(CORR) values for surface C compared to the other surfaces. Results indicate that the surface condition has more effect on corrosion of these alloys than the surface reaction layer. Within the oxidation potential range of the oral cavity, all the metal/surface combinations examined showed excellent corrosion resistance.