A cross-sectional study into the prevalence of root caries in periodontal maintenance patients

Abstract. The aim of this cross-sectional study was to investigate cross-sectionally the prevalence and several risk indicators of root caries in 45 periodontal maintenance patients, who had been actively treated for adult periodontitis 11–22 years ago. These patients were part of a routine 3–6 monthly maintenance schedule. Active and inactive root caries and root fillings were recorded, as well as coronal caries experience. Plaque and bleeding scores, number of exposed root surfaces, rate of saliva secretion, saliva buffering capacity, mutans streptococci counts and Lactobacilli were also scored. From the total of 45 study subjects, 37 patients (82%) showed root lesions (root caries and/or root fillings), while only 8 patients were free of any root lesions. On average, there were 4.3 root lesions per patient (range 0–19) in the present study. 10 patients had active root caries lesions. Of all damaged root surfaces, 9% were active lesions, mostly located on mandibular teeth at lingual and vestibulair sites; 40% were inactive lesions often detected at vestibular sites. The remaining damaged root surfaces (51%) were restored; they were equally divided over both jaws. A higher number of root lesions was observed in those patients with >10⁶mutans streptococci/ ml saliva. Although the actual number of lesions per patient was low in relation to the large number of sites with gingival recession, the results from this cross-sectional study in periodontal maintenance patients indicate that: (1) root caries can be regarded as a complication in periodontal maintenance patients; (2) the individual number of root lesions correlate with individual dental plaque scores; (3) a high number of root lesions is associated with high counts of salivary mutans streptococci; (4) no relation between root caries and coronal caries experience, salivary secretion rate or salivary buffering capacity seems present. Therefore, repeated oral hygiene instructions and adjunctive preventive measures including diet counseling and fluoride rinses, as well as fluoride and chlorhexidine varnishes, should be advocated in high-risk patients.     

Nitric oxide modulates levels of salivary Lactobacilli

Abstract

Objective. Nitric Oxide (NO) is one of the most powerful antibacterial compounds. The aim of this study was to determine the association between salivary NO, dental caries and cariogenic bacteria. Materials and methods. The salivary NO concentration of 257 Korean children was analyzed by the Griess colorimetric reaction method. Salivary mutans streptococci (MS) and Lactobacilli (LB) were counted using the Dentocult MS and Dentocult LB kit, respectively. Dental caries status was examined using the WHO criteria. Confounders were age, gender, salivary flow rate and salivary buffer capacity. Analysis of covariance (ANCOVA) was used to evaluate the association among NO, salivary MS level, salivary LB level and dental caries status after adjusting for the effects of confounders. Results. A significant decrease was found in salivary NO levels as the salivary LB count increased after controlling for confounders (p = 0.049). However, the MS level, caries experience and active caries status showed no significant association. Conclusion. This result indicates that NO production might be a host defense mechanism against the growth of cariogenic bacteria.     

Maternal risk indicators for childhood caries in an inner city population

OBJECTIVES: This study evaluated whether characteristics of mothers, such as high mutans streptococci (MS) level, caries experience, reported sugar consumption and demographic variables, could be important risk indicators of caries for their children. METHODS: Mothers selected on the basis of the caries status of their 3-5-year-old-children were tested for MS, caries, reported sugar consumption and demographic variables. RESULTS: We found strong associations between children's caries and their mothers' MS levels (high/low adj. OR = 11.3), maternal active caries (yes/no adj. OR = 4.0) and maternal sugar consumption (high/low adj. OR = 4.2). In this small study, mothers' demographic variables were not associated with the status of caries in their children. CONCLUSIONS: Our findings suggest that maternal high MS levels, maternal active decay and maternal sugar consumption are strong risk indicators for children's caries. Although further study is needed, these three maternal risk indicators, taken together, may prove useful in predicting children's caries risk.     

Relationship of quantitative salivary levels of Streptococcus mutans and S. sobrinus in mothers to caries status and colonization of mutans streptococci in plaque in their 2.5-year-old children

Abstract – Objectives: The aim of this study was to assess the relationships of quantitative salivary levels of Streptococcus mutans and S. sobrinus in mothers with the colonization of mutans streptococci (MS) in plaque and caries status in their 2.5‐year‐old children. Furthermore, the dynamics of caries status in the children was evaluated in a 2‐year follow‐up survey. Methods: After oral examination of 54 mother‐and‐child pairs, the saliva samples from the mothers and the plaque samples from the children were collected. The levels (log DNA copies/ml saliva) of S. mutans and S. sobrinus were quantified using real‐time polymerase chain reaction (PCR) assays, while MS in the plaque samples were detected using a cultivation method. In addition, 50 of the 54 children participated in a 2‐year follow‐up survey of caries prevalence. Results: In the 2.5‐year‐old children, the percentage of dft‐positive subjects and mean number of dft were significantly higher in the MS(+) group when compared with the MS(?) group. Findings from the 2‐year follow‐up survey indicated that MS(+) subjects had a persistently higher mean number of dft at 4.5 years. The 2.5‐year‐old children were divided into three groups based on the quantitative levels of salivary S. mutans and S. sobrinus in their mothers: those whose mothers had low levels of S. mutans (<4 log DNA copies/ml) and S. sobrinus (<2) (group 1); those whose mothers had a high level of S. mutans (≥4) and low level of S. sobrinus (<2) (group 2); and those whose mothers had high levels of both (≥4 and ≥2, respectively) (group 3). Among the three groups, the percentages of MS(+) and dft‐positive children were highest in group 3 and lowest in group 1. Furthermore, multiple logistic regression analyses revealed that grouping the mothers based on salivary level of S. mutans and S. sobrinus was an efficient means to predict both MS colonization (OR = 2.96) and prevalence of dental caries (OR = 9.39) in children at 2.5 years of age. Conlusions: In the 54 mother‐and‐child pairs tested, the maternal salivary levels of S. mutans and S. sobrinus determined by real‐time PCR were significantly related to MS colonization in plaque as well as dental caries in their children at 2.5 years of age. Thus, determination of maternal levels of both organisms using the present cut‐off values is proposed as an efficient method to indicate the risks of maternal transmission of MS and childhood dental caries.     

Mutans streptococci in subgingival plaque of treated and untreated patients with periodontitis

BACKGROUND: The etiology of root caries is thought to be identical to coronal caries, though root caries seem to be more complicated because of the higher susceptibility of exposed roots (dentin) by periodontal therapy to demineralization than intact enamel. This implies that mutans streptococci are the most likely pathogens in the development of root caries. Although it is known that both the numbers of mutans streptococci and the frequency of isolation in root caries lesions are negatively correlated with the distance from the gingival margin, the subgingival sulcus has not been considered a possible habitat for mutans streptococci. However, subgingival occurrence of mutans streptococci in both untreated and treated periodontal patients has not been documented well in the literature. OBJECTIVE: To investigate the presence and levels of mutans streptococci in the subgingival plaque of patients (n=154) in different stages of periodontal therapy. The subgingival sulcus may be a possible habitat for mutans streptococci. This localisation of mutans streptococci may be of importance in the development of root caries after periodontal surgery. MATERIALS AND METHODS: In this cross-sectional study, subgingival plaque samples from 154 consecutive adult periodontitis patients were tested for presence and levels of mutans streptococci and putative periodontal pathogens by anaerobic cultures. These patients were divided into 4 groups based on their stage of periodontal treatment: (1) untreated patients; (2) patients after initial periodontal therapy only; (3) patients in the maintenance phase who not underwent periodontal surgery; (4) patients after periodontal surgery. RESULTS: The prevalence of mutans streptococci in the 4 study groups varied from 82% in untreated patients to 94% in maintenance patients. The mean proportion of mutans streptococci was 6.65% in maintenance patients versus 1.86% in untreated patients (p=0.005) and 2.51% in patients after scaling and root planing (p=0.041). CONCLUSIONS: The subgingival area is a microbial habitat for mutans streptococci that may be of importance in the development of root caries in periodontitis patients.     

Dental caries and caries-associated microorganisms in Uruguayan preschool children

The prevalence of dental caries was studied in 3-5-year-old Uruguayan children (n = 76) living in 2 areas with different socioeconomic and cultural conditions. More children from the low socioeconomic area of Las Acacias had caries (68%) than children from the middle- to high-class neighborhood of Pocitos (19%). They also had poorer oral hygiene and a significantly higher caries prevalence (P &lt; 0.05) than those from Pocitos. The occurrence of mutans streptococci and lactobacilli was determined in whole unstimulated saliva and compared with that in debris collected with a loop from the dorsum of the tongue. Mutans streptococci were detected in 42% of the children with significant correlations between the salivary levels of the microorganism and caries experience. Lactobacilli were recovered less frequently (18%). The detection of mutans streptococci in the tongue-loop samples was significantly correlated with that in whole saliva.     

Association of salivary mutans streptococci with discoloured pits and fissures

Experimental studies have demonstrated that mutans streptococci play a major role in caries etiology. Several previous epidemiologic studies found a positive association of salivary mutans streptococci with caries prevalence. The present epidemiologic study aimed at detecting a possible association of salivary mutans streptococci with brown discoloured pits and fissures, supposing that discolouration indicates caries. In the Canton of Zurich 1035 schoolchildren, aged 6.5–12.5, were examined with regard to caries prevalence and presence of discolourations in pits and fissures. A commercially available, semi-quantitative test was used to estimate the salivary level of mutans streptococci in each child. The salivary level (low/high) of mutans streptococci was significantly associated with the presence of slightly brown discoloured (C1), clearly brown discoloured (C2) and cavitated (C3) pits and fissures. The odds ratios were 1.5 ( P < 0.01) for C1, 2.5 ( P < 0.001) for C2 and 5.0 ( P < 0.001) for C3 pits and fissures. Then fidings are consistent with the hypothesis that brown discolouration indicates caries. Further-more, then fidings suggest that this type of discolouration at elementary school age indicates increased caries activity.     

Salivary microflora and caries experience in 5-year-old children from two ethnic groups

The purposes of the study were threefold: to compare salivary levels of mutans streptococci and Lactobacillus in 140 5-year-old children from two ethnic groups, to correlate caries experience of each group with bacterial counts, and to determine levels of infectivity which could indicate high caries activity in young children. Pakistani-Muslim and white Caucasian children were paired, matched for age, gender and caries experience. There were no significant differences in mutans streptococci or Lactobacillus levels between the two ethnic groups. However, strong correlations were found between caries experience and levels of both mutans streptococci and Lactobacillus in each ethnic group. Furthermore, mutans streptococci and Lactobacillus levels correlated strongly with one another. For detection of high caries activity, the optimum screening levels of bacteria were > 10(5) cfu/ml for mutans streptococci (sensitivity 78% and specificity 86%) and > 10(4) cfu/ml for Lactobacillus (sensitivity 82% and specificity 89%).     

Mutans streptococci, lactobacilli and caries experience in 12-year-old Icelandic urban children, 1984 and 1991

Abstract In order to evaluate changes in salivary counts of cariogenic bacteria and relate these to trends in caries experience, stimulated saliva was collected from a 20% random sample of 12-yr-old residents of Reykjavik. Iceland (252 children) in 1991 under conditions consistent with those of a survey conducted in 1984. The mean and median counts of salivary mutans streptococci and lactobacilli remained similar in the two studies. However, the frequency distribution at lower levels of mutans streptococci differed significantly between 1991 and 1984, e.g. in the present study 25.8% of the children had < 10⁵ compared with 13.8% in the study 1984. The mean caries prevalence in the permanent dentition (DFS_tot) was 11.0, which is significantly lower than in 1984 (mean DFS_tot 28.8). A significant difference in caries prevalence was found at various levels of salivary mutans streptococci. Strep. mutans (serotype c/e/f) was carried by all mutans streptococci-positive children, save one child, who carried only Strep. sobrinus. The proportion of 12-yr-olds who carried Strep, sobrinus had decreased significantly to 15.7% from 34.0% in 1984. Significantly more children with Strep. sobrinus showed high levels of total mutans streptococci than children with only Strep. mutans. As the case was in 1984 significantly more Strep. sobrinus carriers had a high level of salivary lactobacilli as well as higher caries prevalence than the children who did not carry this species.     

Salivary levels of Bifidobacteria in caries‐free and caries‐active children

International Journal of Paediatric Dentistry 2013; 23: 32–38 Background Salivary levels of Bifidobacteria have been shown to be significantly correlated with caries experience in adults but not as yet in children. Hypothesis. Salivary levels of Bifidobacteria are positively associated with caries experience in children. Aim. To compare the salivary concentrations of Bifidobacteria of caries‐free and caries‐active children. Design. Saliva was collected using the tongue‐loop method from 38 caries‐active children and from 22 clinically caries‐free children, and the numbers of Bifidobacteria, mutans streptococci, lactobacilli and yeasts were determined. Additionally, the age and gender of the children, a plaque index, sugar amount in diet, sugar frequency in diet, hygiene practice and fluoride toothpaste usage were recorded. Results. Bifidobacteria were isolated from 95% of the caries‐active children and from only 9% of the caries‐free children (P < 0.001). Salivary levels of Bifidobacteria were significantly correlated with amount of sugar in the diet, frequency of sugar consumption and oral hygiene practice. The significant variables that discriminated between the caries‐free and caries‐active subjects were salivary levels of Bifidobacteria, salivary levels of mutans streptococci and oral hygiene practice (χ² = 72.57, P < 0.001) and overall 90.0% of cases were correctly classified. Conclusions. Salivary levels of Bifidobacteria are significantly associated with caries experience in children. The salivary levels of this genus may be a useful marker of caries risk.     

学龄前儿童乳牙龋相关因素的分析

目的 评价学龄前儿童的唾液变形链球菌、唾液流速和缓冲力、口腔卫生状况、饮食和口腔卫生习惯、母亲文化程度和职业等因素在乳牙龋发生中的意义.方法 采用病例对照研究方法,对1018名4岁和5岁儿童进行龋齿检查,其中dmft≥6的204人构成高龋组,dmft=0的237人为无龋组.测定两组儿童唾液变形链球菌水平、唾液流速和缓冲力、软垢指数,并由儿童母亲回答统一问卷.结果 共有417名儿童纳入结果的统计中.Logistic回归分析结果显示,唾液变形链球菌(OR=3.019)、软垢指数(OR=2.263)、每天吃甜食次数(OR=1.729)、每天喝甜饮料次数(OR=1.496)、奶瓶内容物含糖(OR=2.255)等因素有意义.结论 唾液变形链球菌水平高、口腔卫生差、高频率摄入甜食、奶瓶喂养时内容物含糖是乳牙龋的重要危险因素.     

Influence of a fluoride mouthrinse on mutans streptococci in schoolchildren

This study aimed to determine whether the long-term use of a fluoride mouthrinse affects the salivary levels of mutans streptococci. Two hundred and fifteen schoolchildren (aged 9-10 years) participated. One hundred and forty-nine of these children had used a fluoride mouthrinse since 5 years of age at nursery school, and the remaining 66 children had not. DFT (decayed and filled teeth) was recorded, and the salivary levels of Streptococcus mutans and Streptococcus sobrinus were measured using mitis salivarius bacitracin agar. The group that had used a fluoride mouthrinse had a significantly lower prevalence of both S. mutans and S. sobrinus (p = 0.038) and a significantly lower DFT score (p < 0.001) than the other group. Using logistic regression analysis including caries experience at baseline as a dependent variable, the odds ratio of carrying S. mutans alone was 8.0 (p = 0.066) and that of carrying both S. mutans and S. sobrinus was 16.5 (p = 0.022) in the group that had not used the fluoride mouthrinse. Children carrying both S. mutans and S. sobrinus had a higher caries incidence in 1 year than the others, with odds ratios of 5.73 (p = 0.067) in the group with a fluoride mouthrinse and 3.47 (p = 0.035) in the group without it. These results show that the long-term use of a fluoride mouthrinse is associated with reduced salivary levels of mutans streptococci and this bacterial reduction may partly contribute to the suppression of dental caries in children using a long-term fluoride mouthrinse.     

Salivary Actinomyces naeslundii genospecies 2 and Lactobacillus casei levels predict pregnancy outcomes

BACKGROUND: Gravida's poor periodontal health is emerging as a modifiable independent risk factor for preterm delivery and low birth weight. METHODS: To test the hypothesis that oral bacteria other than periodontal pathogens are also associated with pregnancy outcomes, specific oral bacterial levels measured during pregnancy were evaluated in relation to gestational age and birth weight while controlling for demographic, medical, and dental variables. The study population consisted of 297 predominantly African- American women who were pregnant for the first time. The salivary bacterial levels evaluated were Streptococcus mutans, Streptococcus sobrinus, Streptococcus sanguinus, Lactobacillus acidophilus, Lactobacillus casei, Actinomyces naeslundii genospecies (gsp) 1 and 2, total streptococci, and total cultivable organisms. RESULTS: For 1 unit increase in log(10) A. naeslundii gsp 2 levels, there was a 60 gm decrease in birth weight (beta = -59.7 g; SE = 29.1; P = 0.04), and a 0.17 week decrease in gestational age (beta = -0.17 wk; SE = 0.09; P = 0.05). In contrast, per 1 unit increase in log(10) L. casei levels, there was a 42 gm increase in birth weight (beta = 42.2 g; SE = 19.3; P = 0.03), and a 0.13 week increase in gestational age (beta = 0.13 week; SE = 0.06; P = 0.04). CONCLUSIONS: We conclude that other oral bacterial species can also be related to pregnancy outcomes in addition to previously reported periodontal pathogens. These organism levels may not only predict poor pregnancy outcomes, but also be used as modifiable risk factors in reducing prematurity and low birth weight.     

Mutans streptococci and caries prevalence in preschool children

Abstract – Numerous studies have reported a correlation between mutans streptococci levels and dental caries. The aim of this study was to assess the relationship between salivary mutans streptococci levels and caries in preschool children of low socioeconomic status. A total of 462 Head Start children, mean age 3.8 yr (range 2.0-5.3 yr), were examined by the modified method of R adike . Saliva samples from 458 of these children were collected with tongue blades and impressed onto mutans streptococci selective agar. Children's mutans streptococci levels were categorized as low (0 CPU), moderate (1–50 CPU) or high (>50 CPU), and the mean dmfs was 0.40, 1.92 and 4.88, respectively. All study groups (Black, Hispanic and White) had infection rates of approximately 83%; however, 39.1% of Black children had high mutans streptococci levels compared with 28.4% of White children. Pit/fissure caries was the most prevalent disease type in children with moderate or high mutans streptococci levels, although White children in the high group had significantly less of this pattern than Blacks and Hispanics. Sensitivity, specificity, and positive and negative predictive values for the high mutans streptococci group were 91.3%, 57.5%. 69.3% and 86.3%. Results from this study indicate that differences between Black, Hispanic and While preschool children may influence caries activity within populations that have similar mutans streptococci infection levels and socioeconomic backgrounds.     

Salivary microbial levels in relation to periodontal status and caries development

Iwano Y, Sugano N, Matsumoto K, Nishihara R, Iizuka T, Yoshinuma N, Ito K. Salivary microbial levels in relation to periodontal status and caries development. J Periodont Res 2010; 45: 165–169. © 2010 John Wiley & Sons A/S Background and Objective: Although an inverse relationship between caries and periodontal disease has been suggested, some studies have reported a positive correlation between periodontal disease and the decayed, missing and filled teeth (DMF) index. The aim of the present study was to examine the relationship between caries and periodontal disease. Material and Methods: We assessed the clinical parameters and salivary levels of Porphyromonas gingivalis and Streptococcus mutans using real‐time polymerase chain reaction in 40 subjects with varying degrees of caries and periodontal disease. Results: The salivary levels of S. mutans were significantly higher in the periodontally healthy group than in the periodontitis group. The salivary levels of P. gingivalis were significantly higher in the caries‐free group than in the periodontally healthy group with caries. The salivary levels of S. mutans were significantly increased after the initial periodontal treatment. Conclusions: This study showed that an inverse relationship exists between periodontitis and caries in terms of the clinical and bacteriological findings.     

Caries prevalence and salivary mutans streptococci in 0–2-year-old children of Japan

The prevalence of caries and the number and species distribution of salivary mutans streptococci in 356 children (aged 0-2 yr old) in Japan were examined twice at an interval of 1 yr. No mutans streptococci were isolated from the predentate children. The detection rate of mutans streptococci and the prevalence of caries increased with age. Mutans streptococci were isolated from 39.9% of the subjects. The majority of isolates were identified as Streptococcus mutans. The concentration of mutans streptococci correlated with the number of erupted teeth (r = 0.339). In addition, the concentration of mutans streptococci was more closely correlated to the caries prevalence of the next year (r = 0.465) than that of the year when the salivary concentration of mutans streptococci was first evaluated (r = 0.368). The children who had no caries but harbored mutans streptococci in the first year showed significantly higher caries prevalence in the next year than did the children with neither caries nor mutans streptococci. These results indicate that the establishment of mutans streptococci is associated with caries initiation in early childhood.     

Correlation among mutans streptococci counts, dental caries, and IgA to Streptococcus mutans in saliva

Two-hundred and forty individuals were studied, divided into five groups as follows: caries-free children, children with caries, children with rampant caries, young adults with and without caries. Whole stimulated saliva was collected and all individuals were investigated for DMFT/dmft according to the WHO criteria and the simplified oral hygiene index (OHI-S). Quantitative analysis of the total aerobic flora and mutans streptococci in saliva was performed. Also, the level of salivary anti-S. mutans IgA was determined by ELISA. Children with rampant caries showed the highest OHI-S value. The highest total counts of microorganisms were found in the group of children with caries. No statistically significant differences were observed for salivary flow, OHI-S and microorganism counts between the groups of young adults. No correlation between mutans streptococci counts and anti-Streptococcus mutans IgA levels was observed in the studied groups. A correlation between increased anti-Streptococcus mutans IgA levels and caries-free status was observed among young adults but not among children.     

Diet intake and caries prevalence in four-year-old children living in a low-prevalence country

Preventive measures have dramatically decreased the prevalence of dental caries in children. However, risk factors for the disease in children living in low-prevalence areas remain elusive. In the present study we evaluated associations between dental caries, saliva levels of mutans streptococci and lactobacilli, and diet with special emphasis on the intake of fermentable carbohydrates and dairy products in 4-year-old children living in an area where the overall caries prevalence was low. Dietary intake was recorded in 234 infants as part of the Study of Infant Nutrition in Ume?, Sweden (SINUS). Of these the parents of 124 children gave consent to participate in a follow-up at 4 years of age. Dietary intake, height and weight, dental caries, oral hygiene, including tooth brushing habits, presence of plaque and gingival inflammation, fluoride habits and numbers of mutans streptococci and lactobacilli in saliva were recorded. Using multivariate stepwise logistic regression, caries experience was negatively associated with intake frequency of cheese (OR = 0.67; 95% CI = 0.44-0.98) and positively associated with the salivary level of mutans streptococci (OR = 1.57; 95% CI = 1.21-2.03). Caries experience was not correlated with intake frequency or amounts of carbohydrate-containing foods, with any other particular food, or with daily intake of energy, carbohydrate or any other macro- or micronutrient. We conclude that cheese intake may have a caries-protective effect in childhood populations where the overall caries prevalence and caries experience are low and the children are regularly exposed to fluoride from toothpaste.     

The relationship between sweetness preference, levels of salivary mutans streptococci and caries experience in Brazilian pre-school children

Aim . To analyse the relationship between preference for sweetness, levels of salivary mutans streptococci and levels of caries in low socio-economic 4–5-year-old Brazilian children.
Design . A cross-sectional survey.
Subjects and methods . 298 children of both sexes, who, in 1998, were regularly attending public nurseries were randomly selected. Caries experience was assessed according to WHO guidelines. Saliva samples were analysed for mutans streptococci using the spatula method. Children's preference for sugar was measured using the 'Sweet Preference Inventory'. Personal interviews with the mothers were conducted.
Results . 255 children completed all aspects of the research, a response rate of 85·6%. 34·9% of them were caries-free. The mean dmf-s was 4·25 (SD 6·16), the decayed component being 3·56 (SD 5·82) and the filled surfaces, 0·69 (SD 1·85). For these pre-school children; male sex ( P < 0·01), single parent ( P < 0·01), habit of eating or drinking items that contained non-milk extrinsic sugar between meal times ( P < 0·05) and high levels of salivary mutans streptococci ( P < 0·001) were significantly associated with higher dmfs scores. There was no statistical relationship between sweetness preference and dental caries and with mutans streptococci levels.
Conclusion . Levels of salivary mutans streptococci but not sweetness preference were potential good predictors of caries experience among 4–5 years-old-children living in urban area of Brazil.     

The association between Porphyromonas gingivalis-specific maternal serum IgG and low birth weight.

BACKGROUND: In Alabama, low birth weight (LBW) infants are about 20 times more likely to die before their first birthday compared to normal birth weight infants. While the rate of LBW has been consistently higher among African Americans compared to whites, there has been a gradual increase in LBW for both African Americans and whites over the last 15 years. In an attempt to identify modifiable risk factors for LBW, we have previously reported that a pregnant woman's poor periodontal health may be an independent risk factor for low birth weight. METHODS: A predominantly African American and socioeconomically homogeneous group of 448 women was followed from the second trimester of their first pregnancy. Thirty-nine LBW cases were observed at the end of follow-up. Using 17 preterm LBW cases and 63 randomly selected controls from the above cohort, the periodontal pathogen-specific maternal serum IgG levels during the second trimester of pregnancy were evaluated in relation to birth weight of the infant, while controlling for known risk factors for LBW. RESULTS: Porphyromonas gingivalis (P.g.)-specific maternal serum IgG levels were higher in the LBW group (mean 58.05, SE = 20.00 microg/ml) compared to the normal birth weight (NBW) group (mean 13.45, SE = 3.92 microg/ml; P= 0.004). Women with higher levels of P.g.-specific IgG had higher odds of giving birth to LBW infants (odds ratio [OR] = 4.1; 95% confidence interval [CI] for odds ratio = 1.3 to 12.8). This association remained significant after controlling for smoking, age, IgG levels against other selected periodontal pathogens, and race. CONCLUSIONS: Low birth weight deliveries were associated with a higher maternal serum antibody level against P. gingivalis at mid-trimester.