Chlorhexidine and preservation of sound tooth structure in older adults. A placebo-controlled trial.

The Trial to Enhance Elderly Teeth Health (TEETH) was designed to test the impact of regular rinsing with a 0.12% chlorhexidine (CHX) solution on tooth loss, and the causes of tooth loss (caries, periodontal disease and trauma) were also investigated. This paper reports on the effectiveness of a 0.12% CHX solution for controlling caries using a tooth surface (coronal and root) survival analysis. A total of 1,101 low income elders in Seattle (United States) and Vancouver (Canada), aged 60-75 years, were recruited for a double-blind clinical trial and assigned to either a CHX (n = 550) or a placebo (n = 551) mouth rinse. Subjects alternated between daily rinsing for 1 month, followed by weekly rinsing for 5 months. All sound coronal and root surfaces at baseline were followed annually for up to 5 years. At each follow-up examination, those tooth surfaces with caries, restored, or extracted were scored as 'carious'. The hazard ratio associated with CHX for a sound surface to become filled, decayed, or extracted was 0.87 for coronal surfaces (95% confidence interval: 0.71-1.14, p = 0.20) and 0.91 for root surfaces (95% confidence interval: 0.73-1.14, p = 0.41). These findings suggest that regular rinsing with CHX does not have a substantial effect on the preservation of sound tooth structure in older adults.

Periodontitis and perceived risk for periodontitis in elders with evidence of depression.

BACKGROUND: Depression and periodontitis are common conditions in older adults. There is some evidence that these two conditions may be related. AIMS: To study a population of dentate elders and assess the prevalence of depression, self-assessment of risk for periodontitis and tooth loss, in relation to periodontal disease status. MATERIAL AND METHODS: Data were obtained from 701 older subjects (mean age 67.2 years (SD+/-4.6), of whom 59.5% were women. Self-reports of a diagnosis of depression, scores of the Geriatric Depression Scale (GDS), and self-assessment of risk for future tooth loss and periodontitis were compared with a diagnosis of periodontitis based on probing depth, and bone loss assessed from panoramic radiographs. Other systemic diseases and smoking habits were also determined and studied in relation to depression. RESULTS: A history of depression was reported by 20% of the subjects. GDS scores >/=8 were reported by 9.8% of the elders. Periodontitis was identified in 48.5% of the subjects. Depression was associated with heart attack (p<0.05), stroke (p<0.01), high blood pressure (p<0.02), all combined cardiovascular diseases (p<0.001), chronic pain (p<0.01), osteoarthritis (p<0.001), and osteoporosis (p< 0.001) but not with periodontitis (p=0.73). Subjects with depression had a higher self-reported risk score for future tooth loss (p<0.02). No group difference emerged for self-perceived risk for periodontitis. Logistic regression analysis demonstrated that a past history of tooth loss (p<0.001), self-perceived risk for periodontitis (p<0.02), the number of years with a smoking habit (p<0.02), and male gender (p<0.02) were associated with a diagnosis of periodontitis but neither measure of depression could be included in an explanatory model for periodontitis. CONCLUSIONS: Evidence of depression (self-report or by GDS) is not associated with risk for periodontitis in older subjects but is associated with tooth loss and chronic conditions associated with pain.

Assessment of periodontal conditions and systemic disease in older subjects.

BACKGROUND: An increased risk for periodontitis has been associated both with type-1 or insulin dependent diabetes (IDDM) and with type-2 or non-insulin dependent diabetes (NIDDM). AIMS: 1) To describe and analyze periodontal conditions in older low-income ethnic diverse subjects with or without a diagnosis of diabetes. 2) To assess to what extent diabetes mellitus is associated with periodontal status, and 3) how periodontitis ranks as a coexisting disease among other diseases in subjects with diabetes mellitus. MATERIAL AND METHODS: Radiographic signs of alveolar bone loss were studied in 1101 older subjects 60-75 years old (mean age 67.6, SD+/-4.7). The number of periodontal sites and the proportions of teeth with probing depth (PD) > or =5 mm, clinical attachment levels (CAL) > or =4 mm were studied in a subset of 701 of the subjects. RESULTS: IDDM was reported by 2.9% and NIDDM by 9.2% of the subjects. The number of remaining teeth did not differ by diabetic status. The number of sites with PD > or =5 mm and the proportion of PD with > or =5 mm was significantly smaller in the non-diabetic group (chi2=46.8, p<0.01, and chi2=171.1, p<0.001, respectively). Statistical analysis failed to demonstrate group differences for the number and proportions of sites with CAL > or =4 mm and for radiographic findings of alveolar bone loss. Combining all periodontal parameters revealed that the Mantel-Haenszel common odds of having IDDM/NIDDM and periodontitis was 1.8 : 1 (95% CI: 1.1-3.1, p<0.03). The common odds ratio estimate of an association between heart disease and diabetes was 3.6 : 1 (95% CI: 2.1-2.6, p<0.001). CONCLUSIONS: Probing depth differences between IDDM/NIDDM vs. non-diabetic subjects may reflect the presences of pseudo-pockets and not progressive periodontitis in many subjects with diabetes mellitus. Periodontitis is not a predominant coexisting disease in older subjects with diabetes mellitus.

Assessment of periodontal conditions and systemic disease in older subjects. I. Focus on osteoporosis.

BACKGROUND: Osteoporosis (OPOR) is a common chronic disease, especially in older women. Patients are often unaware of the condition until they experience bone fractures. Studies have suggested that OPOR and periodontitis are associated diseases and exaggerated by cytokine activity. Panoramic radiography (PMX) allows studies of mandibular cortical index (MCI), which is potentially diagnostic for OPOR. AIMS: i). To study the prevalence of self-reported history of OPOR in an older, ethnically diverse population, ii). to assess the agreement between PMX/MCI findings and self-reported OPOR, and iii). to assess the likelihood of having both a self-reported history of OPOR and a diagnosis of periodontitis. MATERIALS AND METHODS: PMX and medical history were obtained from 1084 subjects aged 60-75 (mean age 67.6, SD +/- 4.7). Of the films, 90.3% were useful for analysis. PMXs were studied using MCI. The PMXs were used to grade subjects as not having periodontitis or with one of three grades of periodontitis severity. RESULTS: A positive MCI was found in 38.9% of the subjects, in contrast to 8.2% self-reported OPOR. The intraclass correlation between MCI and self-reported OPOR was 0.20 (P < 0.01). The likelihood of an association between OPOR and MCI was 2.6 (95%CI: 1.6, 4.1, P < 0.001). Subjects with self-reported OPOR and a positive MCI had worse periodontal conditions (P < 0.01). The Mantel-Haentzel odds ratio for OPOR and periodontitis was 1.8 (95%CI: 1.2, 2.5, P < 0.001). CONCLUSIONS: The prevalence of positive MCI was high and consistent with epidemiological studies, but only partly consistent with a self-reported history of osteoporosis with a higher prevalence of positive MCI in Chinese women. Horizontal alveolar bone loss is associated with both positive self-reported OPOR and MCI.

Assessment of periodontal conditions and systemic disease in older subjects. II. Focus on cardiovascular diseases.

BACKGROUND: Panoramic radiographs (PMX)s may provide information about systemic health conditions. AIMS: i). To study clinical periodontal conditions and collect self-reported health status in a cohort of 1084 older subjects; ii). to study signs of alveolar bone loss and carotid calcification from panoramic radiographs obtained from these subjects; and iii). to study associations between study parameters. MATERIAL AND METHODS: PMXs from 1064 adults aged 60-75 (mean age 67.6, SD +/- 4.7) were studied. Signs of alveolar bone loss, vertical defects, and molar furcation radiolucencies defined periodontal status. Medical health histories were obtained via self-reports. Signs of carotid calcification were identified from panoramic radiographs. RESULTS: The PMX allowed assessment of 53% of the films (Seattle 64.5% and Vancouver 48.4%). A self-reported history of a stroke was reported by 8.1% of men in Seattle and 2.9% of men in Vancouver (P < 0.01). Heart attacks were reported by 12% of men in Seattle and 7.2% in Vancouver (N.S.). PMX evidence of periodontitis was found in 48.5% of the subjects, with carotid calcification in 18.6%. The intraclass correlation score for PMX findings of carotid calcification and stroke was 0.24 (95% CI: 0.10-0.35, P < 0.001). The odds ratio for PMX carotid calcification and periodontitis was 2.1 (95% CI: 1.3-3.2, P < 0.001), and for PMX carotid calcification and stroke 4.2 (95% CI: 1.9-9.1, P < 0.001). The associations disappeared when smoking was accounted for. A history of a heart attack was associated with stroke, gender, age, and PMX scores of alveolar bone loss. CONCLUSIONS: PMXs may provide valuable information about both oral conditions and signs of carotid calcification, data that are consistent with self-reported health conditions. Alveolar bone loss as assessed from PMXs is associated with cardiovascular diseases.

Characteristics of dental emergency clinic patients with and without disabilities.

This study compared oral health and demographic characteristics of patients with and without disabilities at a dental school emergency clinic. Of 407 consecutive patients surveyed, 20.4% reported disabilities. Two groups matched by age and gender, those with disabilities (DIS, n = 79) and those without disabilities (ND, n = 177), were compared on questionnaire responses; two subgroups, DIS (n = 38) and ND (n = 44), were assessed clinically. The mean ages of the DIS and ND groups were 44.0 years (SD +/- 11.6) and 43.0 years (SD +/- 12.3), respectively. By chi-squared analysis, DIS vs. ND subjects had significantly lower levels of education, employment, income, and dental insurance, and greater dependence on Government funding. In the DIS group, 79.5% were not working, while 6.4% did work regularly. In the ND group, the corresponding values were 30.9% and 46.9%, respectively. In the DIS group, 51.9% identified Medicaid acceptance as the reason they sought care at the clinic, while 62.7% of the subjects in the ND group identified the lower fee structure as the reason for clinic selection. More DIS than ND subjects reported dentists' unavailability and inability to manage the disability, lack of transportation, effect of dental problems on health, and referral by a health professional. DIS vs. ND subjects had significantly fewer sound teeth and more missing teeth. The results suggest that one in five dental school emergency clinic patients has disabilities.

Caries prevention in a community-dwelling older population.

A clinical trial was conducted to compare the effect of different caries-preventive strategies on caries progression in lower-income, ethnically diverse persons 60 years of age and older. Two hundred and ninety-seven subjects were randomized into one of five experimental groups. Group 1 received usual care from a public health department or a private practitioner. Group 2 received an educational program of 2 h duration implemented twice a year. Group 3 received the educational program plus a 0.12% chlorhexidine rinse weekly. Group 4 received the education and chlorhexidine interventions and a fluoride varnish application twice a year. Group 5 received all the above interventions as well as scaling and root planing every 6 months throughout the 3-year study. A carious event was defined as the onset of a carious lesion, a filling, or an extraction on a surface which was sound at baseline. Two hundred and one subjects remained in the study for the 3-year period. Groups that received usual intraoral procedures (groups 3, 4, and 5) had a 27% reduction for coronal caries events (p = 0.09) and 23% for root caries events (p = 0.15), when compared to the groups that received no intraoral procedures (groups 1 and 2). Routine preventive treatments may have had only a small-to-moderate effect upon caries development.

Clinical and microbiological findings in elderly subjects with gingivitis or periodontitis.

The objective of the present study was to study the supra- and subgingival microflora by culture and cDNA probe methods in 20 elderly subjects who were between 62 and 93 years of age. 10 of them had gingivitis only, and 10 had periodontitis. B. forsythus (BF), P. gingivalis (PG), P. intermedia (PI), P. nigrescens (PN), A. actinomycetemcomitans (AA), T. denticola (TD), and pathogen-related oral spirochetes (PROS) were studied. Oral hygiene was similar and poor in both groups. The mean probing depth at sample sites was 6.7 mm (S.D+/-1.3) in the periodontitis group and 2.2 mm (S.D.+/-1.5) in the gingivitis group (F=17.75, p<0.001). Mean clinical attachment levels (CAL) were 4.3 mm (S.D.+/-2.0) and 1.7 mm (S.D.+/-0.9) respectively (p<0.001). Total viable counts >1.0x10(5) in supra-gingival plaque samples were found in all periodontitis and in eight gingivitis subjects. 70x more black-pigmented organisms were found in supra-gingival and 185 times more in sub-gingival plaque from the periodontitis group (p<0.01). Culture data showed P. nigresecens in 10% periodontitis and 50% gingivitis subjects (p<0.03). In supra-gingival samples by the Affirm DP test, BF was present in 50% periodontitis and 60% gingivitis while culture data were negative for all subjects. PG was found in 30% periodontitis and 50% gingivitis subjects with TD in 70% periodontitis and in 30% gingivitis subjects. In the sub-gingival plaque samples 80% periodontitis and 70% gingivitis subjects had >1x10(5) anaerobes. The total count of black-pigmented organisms was significantly greater in the periodontitis elders (p<0.001). cDNA probes by the Affirm DP test identified subgingival presence of BF (80%) PG (80%), PI (80%), AA (0%), TD (50%) in periodontitis subjects with BF (70%), PG (40%), PI (30%) and TD (20%) in gingivitis subjects. PROS were found in (80%) samples from periodontitis and in (60%) of gingivitis elderly. Only the quantities of PI (r=0.48, p<0.01) and TD (r=0.37, p<0.01) were associated with the disease definition. The smoking habit in the periodontitis group was significantly higher (p<0.01). A history of smoking may contribute significantly to periodontitis in the presence of pathogens.

Alveolar bone levels in AIDS and HIV seropositive patients and in control subjects.

Alveolar bone levels were studied from intraoral radiographs of 24 non-hospitalized patients with AIDS, 17 HIV seropositive subjects, and 39 matched control subjects. The AIDS/HIV subjects were seeking dental care in a faculty practice. The matched control subjects came from those non-HIV-infected patients seeking dental care at the University of Washington. Magnified intraoral radiographs were used to assess the distance between the cemento-enamel junction (CEJ) and the alveolar bone level (BL). The extent of vertical defects and furcation invasions was also assessed. The mean age of the AIDS, HIV, and control subjects was 38.9 +/- 6.6 years, 37.1 +/- 7.6, and 39.9 +/- 5.6, respectively, and was not statistically different. Among the AIDS patients, 75% were smokers, while 88.2% of the HIV subjects were cigarette smokers. Therefore, the matched control subjects were also smokers to the same extent. The mean difference in distance CEJ-BL was 0.1 mm (mesial) and 0.3 mm (distal) and greater in the HIV/AIDS group than in the control group, but not statistically different. No vertical defects > or = 3.0 mm were found in 69.2% of the control subjects and in 58.5% of the combined HIV/AIDS group. None of the HIV/AIDS subjects had more than 5 defects > 3.0 mm, while 7.6% of the control subjects had such defects. Significant associations were found between smoking and extent of alveolar bone loss (distance) (P < 0.001) as well as the number and extent of vertical defects (P < 0.01), but were not associated with HIV status. The extent of furcation invasions, as read radiographically, did not differ between groups. In conclusion, smoking but not HIV status was the primary factor for alveolar bone loss.

Assessment of alveolar bone levels from intraoral radiographs in subjects between ages 15 and 94 years seeking dental care.

Studies have shown that <20% of the US population has periodontal disease. Studies of radiographs have shown that alveolar bone loss increases with age. Bone loss assessed from intraoral radiographs describing 10,282 teeth from 416 subjects seeking dental care during a 3 month period at the University of Washington were studied. The mean age of the subjects was 47.2 years (SD+/-15.2). The youngest subjects (15-24) had on average 29.6 teeth (SD+/-2.2) and the oldest subjects (75-94) 19.3 teeth (SD+/-6.6). This difference was statistically significant (F=16.57, p<0.001). No association was found between alveolar bone loss (CEJ-ABC), and TMD symptoms. Smoking was significantly associated with both general bone loss (CEJ-ABC) (chi(2)=114.9, p<0.0001), and vertical bone defects (angular) (chi(2)=101.8, p<0.0001). In this study population (15-94 years), alveolar bone loss progressed as defined by the slope (beta=0.29) between age 15-44, but was almost flat from age 50 years (beta=0.04). The data suggested an overall rate of alveolar bone loss of 0.02 mm per year. Stepwise multiple regression analysis showed that smoking was the primary factor in bone loss (t= 7.7, p<0.0001), followed by age (t=7.0, p<0.001) and gender (t=3.0, p<0.01). TMD symptoms could not explain the presence and severity of horizontal or vertical defects. If the CEJ-ABC distance above the mean plus 2x the SD was used as the cutoff value to define abnormal bone levels, 10.9% of the younger (15-45 years), and 10.7% of the older subjects (50-94) had significant alveolar bone loss. 73.9% of the younger and 100% of the older subjects with such extent of alveolar bone loss were smokers.

Oral health and medical status in dentate low-income older persons.

Oral and medical conditions of 295 low-income dentate older persons (17% African-Americans, 14.5% Asians, 11.5% Hispanics, and 57% Caucasians) were studied. The mean age was 72 (SD +/- 6.8; range, 60-91). Oral examinations were performed, stimulated saliva was collected, and interviews were conducted regarding oral health attitudes, knowledge, and behaviors. Past history of restorative care, defined by filled coronal surfaces, differed by ethnicity, with Caucasian elders having most filled surfaces (p < 0.001). Ethnic minority elders had significantly poorer periodontal health (p < 0.001), with the worst conditions in Asians. Low salivary flow (< 0.01 mL/min) was found in 31% using medications known to cause hyposalivation. Frequent diseases were arthritis (46%), hypertension (39%), heart disease (25.2%), and diabetes (8.5%). Hypothyroidism was associated with low flow rate (F = 13.2, p < 0.0003). Seventy percent reported that they had never smoked. Smokers had deeper probing depths (chi 2 = 11.98, p < 0.05) and more gingival recession (F = 8.08, p < 0.001). Women on hormone replacement therapy (HRT) had less calculus (F = 11.33, p < 0.01) and fewer sites with probing depths > 5 mm (F = 8.99, p < 0.003). The present study found few associations between physical and oral health and ethnicity. The benefits of HRT for women's periodontal health and the effects of hypothyroidism on stimulated salivary flow are noteworthy.

Factors associated with caries incidence in an elderly population.

The purpose of this paper was to identify baseline factors associated with future caries development in older adults (age 60+) during a 3-year study period. Poisson regression analysis was used to determine the association between potential risk factors and disease incidence. The significant factors associated with high coronal caries incidence rates were high baseline root DMFS (P<0.001), high counts of mutans streptococci and lactobacilli (P=0.036), male gender (P=0.007), and Asian ethnicity (P=0.002). These factors had small to moderate effects on incidence rates, with relative risk values of approximately 1.2 to 2. The significant factors associated with higher disease incidence on root surfaces were baseline coronal DMFS (marginally significant, P=0.078), high bacterial counts (P=0.002), and Asian ethnicity (P=0.009). The predictive value of the models was low for both coronal and root caries. This result may be because this population had a higher than usual caries incidence rate, making discrimination among these caries-active individuals difficult. The current study affirmed the value of baseline DMFS and salivary variables to modeling caries incidence and introduced ethnicity as a variable useful for the study of dental caries in older adults.

Horizontal alveolar bone loss and vertical bone defects in an adult patient population.

The objectives of the present investigation were to analyze intraoral radiographs and to study 1) the distribution of the distance between the cemento-enamel junction (CEJ) and the alveolar bone level (BL) and 2) the prevalence and severity of vertical defects, and furcation lesions in 416 individuals seeking dental care. Full mouth radiographs were enlarged 7.5 times and the mesial and distal distances between CEJ and bone level were measured. The extent of interradicular molar radiolucencies was also measured. Images of 10,282 teeth were studied. Subjects were between 15 to 94 years (mean age: 47.2, S.D.+/-15.2). On average they had 24.8 teeth (S.D.+/-5.5). The mean distance CEJ-BL increased significantly up to age 45 (r2=0.07; beta=0.29; P < 0.0001) and remained stable thereafter r2=0.09, beta=-0.02, N.S.). The mean distance CEJ-bone level was 1.4 mm (S.D.+/-0.7) in the 15 to 24 age group; 3.0 (S.D.+/-1.5) in the 45 to 54 age group; and 3.02 (S.D.+/-1.4) in the 75 to 94 age group. No vertical defects were found in 163 participants (39.3%); vertical defects > or = 3.0 mm were found in 30.2% (126). Mesial defects were significantly more common that distal defects (P < 0.001). The extent of horizontal bone loss was correlated to extent of vertical defects (r2=0.88; P < 0.0001). The number of remaining teeth was not associated with horizontal or vertical bone loss. In conclusion, the study indicated that few of the individuals had extensive horizontal bone loss. Vertical defects suitable for guided tissue regeneration procedures however, were found in many patients.

Periodontal effects of a biobehavioral prevention program.

The present study tested preventive regimens in older subjects using dental services sporadically. 297 persons aged 60-90 (mean age 72.8; 43% ethnic minorities), were randomly assigned to either a control group or four interventions with incrementally more complex preventive strategies; behavioral training (group 2), added weekly chlorhexidine rinse (group 3), added semi-annual fluoride varnish (group 4), and added semi-annual prophylaxis (group 5). The control group received dental care as they preferred, primarily emergency care. All subjects were re-examined annually for 3 years. At baseline, 190 (64%) of the subjects were considered at risk for future periodontal disease progression. At baseline there were no group differences for any clinical parameter studied. Gingival bleeding varied between 19% and 23% over time and with no group differences. After 1 year, the greater decrease in probing depth for group 5 approached significance compared to the control group (p<0.06). Clinical attachment levels (CAL) improved in group 5 compared to the control group (p<0.01 for mesio-buccal, p<0.05 for mid-buccal tooth surfaces). The group differences did not persist at year 3. At year 3 in group 1, 9.2% and in group 5, 4.9% subjects lost > or =2.0 mm CAL. 310 teeth (6.5%) were extracted during the study period. A 21% increased risk for tooth loss was found in group 2, a 15% reduced risk in group 3, a 28% reduced risk in group 4, and a 44% reduced risk in group 5 compared to the control group (Wald-statistics robust p-value 0.12). At year 3, the tooth mortality rate in groups 3, 4 and 5 combined was reduced to 59% and significantly lower than groups 1 and 2 together (p<0.04). Self-efficacy was the best predictor of periodontal disease progression (F=7.02, p<0.01). Thus older persons benefited from a preventive oral health care program.

Periodontal conditions in medically compromised elderly subjects: assessments of treatment needs.

Periodontal conditions were studied in 42 dentate elderly subjects (mean age, 84.1 +/- 8.0 years). None of them had received recent dental care or was routinely seen by a dentist. Overall, they had 20.2 +/- 7.1 teeth (range, 6-32). The CPITN was used to assess periodontal status. Twenty-nine percent of all sextants were either edentulous or had only one remaining tooth. The overall oral hygiene was poor (Plaque Index, 1.8 +/- 0.5) and gingival inflammation severe (Gingival Index, 1.9 +/- 0.8). Significant correlations were found between: Gingival and Plaque Indices (r = 0.82, p < 0.001), and pocket depth and Gingival Index (r = 0.38, p < 0.05). Plaque Index was negatively correlated to the number of remaining teeth (r = -0.43, p < 0.050). Age and remaining teeth were negatively correlated (r = -0.38, p < 0.05). Thirty percent of the posterior sextants had a CPITN score of "4," and 75% of the posterior sextants had at least one site with a pocket depth 4 mm. Only 2.9% of all sites demonstrated pocket depth 6 mm and these sites were distributed among 67% of the subjects. The CPITN index was correlated to the mean pocket depth for the various sextants, the correlation varying between r = 0.67, p < 0.001 (upper right posterior) and 0.36, p < 0.05 (upper left posterior) sextants. The total manpower estimated to complete initial therapy for 42 patients was approximately 63 hours by a dentist and 85 hours by a dental hygienist.

Involvement of Porphyromonas gingivalis fimbriae in adherence to Streptococcus gordonii.

Adherence of Porphyromonas gingivalis to early plaque bacteria, such as Streptococcus gordonii, is considered an important colonization mechanism. The molecules that mediate this interspecies binding have not been determined. Fimbriae were prepared from P. gingivalis 33277 by mild agitation, ammonium sulfate precipitation and DEAE-Sepharose chromatography. In a nitrocellulose blot adherence assay, purified fimbriae inhibited S. gordonii G9B-P. gingivalis 33277 binding by up to 54%. In addition, fimbriae bound to S. gordonii cells in a dot-blot assay. Incubation of fimbriae with S. gordonii cells followed by washing, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), electroblotting and probing with P. gingivalis antibodies also revealed that the fimbriae bind to S. gordonii. In contrast, S. gordonii did not interact with fimbriae that were first subjected to SDS-PAGE and electroblotting or deposited on a nitrocellulose membrane, suggesting that conformational determinants of the fimbriae may be important in binding. The results indicate that binding between P. gingivalis and S. gordonii is mediated, at least in part, by the porphyromonads' fimbriae.

Interaction of Porphyromonas gingivalis with gingival epithelial cells maintained in culture.

Interactions between Porphyromonas gingivalis and gingival epithelial cells were investigated. Gingival epithelial cells were cultured from surgically removed gingival tissue. Electron microscopy demonstrated adherence of P. gingivalis to the cell membranes and microvilli followed by internalization of the bacteria into the epithelial cell cytoplasm. Saliva from healthy and periodontally diseased patients inhibited P. gingivalis association with the epithelial cells. Attachment to and penetration of gingival epithelial cells by P. gingivalis may be important virulence factors in periodontal disease. Salivary molecules may play a role in modulating these interactions.

Therapeutic effects of daily or weekly chlorhexidine rinsing on oral health of a geriatric population.

The effects of a chlorhexidine rinse on salivary Streptococcus mutans, Lactobacillus, and Candida albicans counts and on periodontal conditions (gingival index, plaque index, pocket depths) were studied in 42 elderly subjects. Under supervision, they rinsed either daily or weekly for 6 weeks with a 0.12% chlorhexidine solution (Peridex). Saliva samples were taken for chemical and microbiologic examinations, and periodontal conditions were assessed at baseline, week 6, and 6 weeks after final rinse. Significantly lower S. mutans counts were found at week 6 for both rinsing groups (p less than 0.001). Lactobacillus and Candida counts were also generally lower at week 6, with the clearest improvement among persons with the highest counts of bacteria and yeast. Periodontal conditions were improved at week 6 (p less than 0.001) in both groups. Such improvements were not maintained 6 weeks after the rinsing regimen was completed. At baseline poor oral conditions were noticed, which placed most of the subjects at risk for tooth decay and periodontal disease. Without any other dental procedures but daily or weekly supervised rinsing, oral conditions were improved and this risk was reduced. Daily rinsing was not superior to weekly rinsing with 0.12% chlorhexidine.