University of Dental Medicine

It has been recognized for some time that bacterial species exist in complexes in subgingival plaque. The purpose of the present investigation was to attempt to define such communities using data from large numbers of plaque samples and different clustering and ordination techniques. Subgingival plaque samples were taken from the mesial aspect of each tooth in 185 subjects (mean age 51 +/- 16 years) with (n = 160) or without (n = 25) periodontitis. The presence and levels of 40 subgingival taxa were determined in 13,261 plaque samples using whole genomic DNA probes and checkerboard DNA-DNA hybridization. Clinical assessments were made at 6 sites per tooth at each visit. Similarities between pairs of species were computed using phi coefficients and species clustered using an averaged unweighted linkage sort. Community ordination was performed using principal components analysis and correspondence analysis. 5 major complexes were consistently observed using any of the analytical methods. One complex consisted of the tightly related group: Bacteroides forsythus, Porphyromonas gingivalis and Treponema denticola. The 2nd complex consisted of a tightly related core group including members of the Fusobacterium nucleatum/periodonticum subspecies, Prevotella intermedia, Prevotella nigrescens and Peptostreptococcus micros. Species associated with this group included: Eubacterium nodatum, Campylobacter rectus, Campylobacter showae, Streptococcus constellatus and Campylobacter gracilis. The 3rd complex consisted of Streptococcus sanguis, S. oralis, S. mitis, S. gordonii and S. intermedius. The 4th complex was comprised of 3 Capnocytophaga species, Campylobacter concisus, Eikenella corrodens and Actinobacillus actinomycetemcomitans serotype a. The 5th complex consisted of Veillonella parvula and Actinomyces odontolyticus. A. actinomycetemcomitans serotype b, Selenomonas noxia and Actinomyces naeslundii genospecies 2 (A. viscosus) were outliers with little relation to each other and the 5 major complexes. The 1st complex related strikingly to clinical measures of periodontal disease particularly pocket depth and bleeding on probing.

Growing recognition that quality of life is an important outcome of dental care has created a need for a range of instruments to measure oral health-related quality of life. This study aimed to derive a subset of items from the Oral Health Impact Profile (OHIP-49)-a 49-item questionnaire that measures people's perceptions of the impact of oral conditions on their well-being. Secondary analysis was conducted using data from an epidemiologic study of 1217 people aged 60+ years in South Australia. Internal reliability analysis, factor analysis and regression analysis were undertaken to derive a subset (OHIP-14) questionnaire and its validity was evaluated by assessing associations with sociodemographic and clinical oral status variables. Internal reliability of the OHIP-14 was evaluated using Cronbach's coefficient alpha. Regression analysis yielded an optimal set of 14 questions. The OHIP-14 accounted for 94% of variance in the OHIP-49; had high reliability (alpha = 0.88); contained questions from each of the seven conceptual dimensions of the OHIP-49; and had a good distribution of prevalence for individual questions. OHIP-14 scores and OHIP-49 scores displayed the same pattern of variation among sociodemographic groups of older adults. In a multivariate analysis of dentate people, eight oral status and sociodemographic variables were associated (P < 0.05) with both the OHIP-49 and the OHIP-14. While it will be important to replicate these findings in other populations, the findings suggest that the OHIP-14 has good reliability, validity and precision.

The interpretation of diagnostic tests for the detection of subgingival bacterial species is dependent on knowledge of the microbial etiology of destructive periodontal diseases. Specific etiologic agents of these diseases have been sought for over 100 years; however, the complexity of the microbiota, an incomplete understanding of the biology of periodontal diseases, and technical problems have handicapped this search. Nonetheless, a number of possible pathogens have been suggested on the basis of their association with disease, animal pathogenicity, and virulence factors. The immunological response of the host to a species and the relation of successful therapy to the elimination of the species have also been used to support or refute suspected periodontal pathogens. Current data suggest that pathogens are necessary but not sufficient for disease activity to occur. Factors which influence activity include susceptibility of the individual host and the presence of interacting bacterial species which facilitate or impede disease progression. Recent studies have attempted to distinguish virulent and avirulent clonai types of suspected pathogenic species and seek transmission of genetic elements needed for pathogenic species to cause disease. Finally, the local environment of the periodontal pocket may be important in the regulation of expression of virulence factors by pathogenic species. Thus, in order that disease result from a pathogen, 1) it must be a virulent clonal type; 2) it must possess the chromosomal and extra-chromosomal genetic factors to initiate disease; 3) the host must be susceptible to this pathogen; 4) the pathogen must be in numbers sufficient to exceed the threshold for that host; 5) it must be located at the right place; 6) other bacterial species must foster, or at least not inhibit, the process; and 7) the local environment must be one which is conducive to the expression of the species' virulence properties. J Periodontol 1992; 63:322-331.

CONTEXT: The Women's Health Initiative (WHI) trial of estrogen plus progestin was stopped early because of adverse effects, including an increased risk of stroke in the estrogen plus progestin group. OBJECTIVE: To assess the effect of estrogen plus progestin on ischemic and hemorrhagic stroke and in subgroups, and to determine whether the effect of estrogen plus progestin was modified by baseline levels of blood biomarkers. DESIGN: Multicenter double-blind, placebo-controlled, randomized clinical trial involving 16 608 women aged 50 through 79 years with an average follow-up of 5.6 years. Baseline levels of blood-based markers of inflammation, thrombosis, and lipid levels were measured in the first 140 centrally confirmed stroke cases and 513 controls. INTERVENTIONS: Participants received 0.625 mg/d of conjugated equine estrogen plus 2.5 mg/d of medroxyprogesterone acetate (n = 8506) or placebo (n = 8102). MAIN OUTCOME MEASURES: Overall strokes and stroke subtype and severity were centrally adjudicated by stroke neurologists. RESULTS: One hundred fifty-one patients (1.8%) in the estrogen plus progestin and 107 (1.3%) in the placebo groups had strokes. Overall 79.8% of strokes were ischemic. For combined ischemic and hemorrhagic strokes, the intention-to-treat hazard ratio (HR) for estrogen plus progestin vs placebo was 1.31 (95% confidence interval [CI], 1.02-1.68); with adjustment for adherence, the HR was 1.50 (95% CI, 1.08-2.08). The HR for ischemic stroke was 1.44 (95% CI, 1.09-1.90) and for hemorrhagic stroke, 0.82 (95% CI, 0.43-1.56). Point estimates of the HRs indicate that excess risk of all stroke was apparent in all age groups, in all categories of baseline stroke risk, and in women with and without hypertension, prior history of cardiovascular disease, use of hormones, statins, or aspirin. Other risk factors for stroke, including smoking, blood pressure, diabetes, lower use of vitamin C supplements, blood-based biomarkers of inflammation, higher white blood cell count, and higher hematocrit levels did not modify the effect of estrogen plus progestin on stroke risk. CONCLUSIONS: Estrogen plus progestin increases the risk of ischemic stroke in generally healthy postmenopausal women. Excess risk for all strokes attributed to estrogen plus progestin appeared to be present in all subgroups of women examined.

The commensal fungus Candida albicans causes oropharyngeal candidiasis (OPC; thrush) in settings of immunodeficiency. Although disseminated, vaginal, and oral candidiasis are all caused by C. albicans species, host defense against C. albicans varies by anatomical location. T helper 1 (Th1) cells have long been implicated in defense against candidiasis, whereas the role of Th17 cells remains controversial. IL-17 mediates inflammatory pathology in a gastric model of mucosal candidiasis, but is host protective in disseminated disease. Here, we directly compared Th1 and Th17 function in a model of OPC. Th17-deficient (IL-23p19(-/-)) and IL-17R-deficient (IL-17RA(-/-)) mice experienced severe OPC, whereas Th1-deficient (IL-12p35(-/-)) mice showed low fungal burdens and no overt disease. Neutrophil recruitment was impaired in IL-23p19(-/-) and IL-17RA(-/-), but not IL-12(-/-), mice, and TCR-alphabeta cells were more important than TCR-gammadelta cells. Surprisingly, mice deficient in the Th17 cytokine IL-22 were only mildly susceptible to OPC, indicating that IL-17 rather than IL-22 is vital in defense against oral candidiasis. Gene profiling of oral mucosal tissue showed strong induction of Th17 signature genes, including CXC chemokines and beta defensin-3. Saliva from Th17-deficient, but not Th1-deficient, mice exhibited reduced candidacidal activity. Thus, the Th17 lineage, acting largely through IL-17, confers the dominant response to oral candidiasis through neutrophils and antimicrobial factors.

1. Six hundred patients in a private periodontal practice were reexamined an average of 22 years after their active treatment and the patterns of tooth loss were observed. 2. During the post-treatment period, 300 patients had lost no teeth from periodontal disease, 199 had lost one to three teeth, 76 had lost 4 to 9 teeth and 25 had lost 10 to 23 teeth. 3. Of 2,139 teeth that originally had been considered of questionable prognosis, 666 were lost. Of these, 394 were lost by one sixth of the patients and only 272 by the other five-sixths. 4. Of 1,464 teeth which originally had furcation involvements, 460 were lost, 240 of them by one-sixth of the patients who deteriorated most. 5. The mortality of teeth which were treated with periodontal surgery was compared with that of teeth which did not have surgery. Tooth retention seemed more closely related to the case type than the surgery performed. 6. In general, periodontal disease is bilaterally symmetrical and there is a predictable order of likelihood of tooth loss according to position in the arch.

Increasing attention has been focused on understanding bacterial biofilms and this growth modality's relation to human disease. In this review we explore the genetic regulation and molecular components involved in biofilm formation and maturation in the context of the Gram-positive cocci, Staphylococcus aureus. In addition, we discuss diseases and host immune responses, along with current therapies associated with S. aureus biofilm infections and prevention strategies.

PURPOSE: We wanted to review and synthesize published criteria for good qualitative research and develop a cogent set of evaluative criteria. METHODS: We identified published journal articles discussing criteria for rigorous research using standard search strategies then examined reference sections of relevant journal articles to identify books and book chapters on this topic. A cross-publication content analysis allowed us to identify criteria and understand the beliefs that shape them. RESULTS: Seven criteria for good qualitative research emerged: (1) carrying out ethical research; (2) importance of the research; (3) clarity and coherence of the research report; (4) use of appropriate and rigorous methods; (5) importance of reflexivity or attending to researcher bias; (6) importance of establishing validity or credibility; and (7) importance of verification or reliability. General agreement was observed across publications on the first 4 quality dimensions. On the last 3, important divergent perspectives were observed in how these criteria should be applied to qualitative research, with differences based on the paradigm embraced by the authors. CONCLUSION: Qualitative research is not a unified field. Most manuscript and grant reviewers are not qualitative experts and are likely to embrace a generic set of criteria rather than those relevant to the particular qualitative approach proposed or reported. Reviewers and researchers need to be aware of this tendency and educate health care researchers about the criteria appropriate for evaluating qualitative research from within the theoretical and methodological framework from which it emerges.

Cyclooxygenase (COX)-2 expression was immunohistochemically examined in 59 human lung cancers as well as in normal and premalignant lung specimens. In contrast to scattered weak reactivity seen in normal peripheral airway epithelial cells, markedly up-regulated COX-2 expression was detected in about one-third of atypical adenomatous hyperplasias and carcinoma in situ specimens, and a significant increase in COX-2 expression was observed in 70% of invasive adenocarcinoma cases. Interestingly, the proportion of adenocarcinoma cells with marked COX-2 expression was much greater in lymph node metastases than in the corresponding primary tumors. In contrast, small cell carcinomas showed virtually negligible expression, and squamous cell carcinomas showed infrequent and low expression. These findings suggest that an increase in COX-2 expression may be associated with the development of adenocarcinomas and possibly with acquisition of an invasive and metastatic phenotype.

PURPOSE: Oral fluid (saliva) meets the demand for noninvasive, accessible, and highly efficient diagnostic medium. Recent discovery that a large panel of human RNA can be reliably detected in saliva gives rise to a novel clinical approach, salivary transcriptome diagnostics. The purpose of this study is to evaluate the diagnostic value of this new approach by using oral squamous cell carcinoma (OSCC) as the proof-of-principle disease. EXPERIMENTAL DESIGN: Unstimulated saliva was collected from patients (n = 32) with primary T1/T2 OSCC and normal subjects (n = 32) with matched age, gender, and smoking history. RNA isolation was done from the saliva supernatant, followed by two-round linear amplification with T7 RNA polymerase. Human Genome U133A microarrays were applied for profiling human salivary transcriptome. The different gene expression patterns were analyzed by combining a t test comparison and a fold-change analysis on 10 matched cancer patients and controls. Quantitative polymerase chain reaction (qPCR) was used to validate the selected genes that showed significant difference (P < 0.01) by microarray. The predictive power of these salivary mRNA biomarkers was analyzed by receiver operating characteristic curve and classification models. RESULTS: Microarray analysis showed there are 1,679 genes exhibited significantly different expression level in saliva between cancer patients and controls (P < 0.05). Seven cancer-related mRNA biomarkers that exhibited at least a 3.5-fold elevation in OSCC saliva (P < 0.01) were consistently validated by qPCR on saliva samples from OSCC patients (n = 32) and controls (n = 32). These potential salivary RNA biomarkers are transcripts of IL8, IL1B, DUSP1, HA3, OAZ1, S100P, and SAT. The combinations of these biomarkers yielded sensitivity (91%) and specificity (91%) in distinguishing OSCC from the controls. CONCLUSIONS: The utility of salivary transcriptome diagnostics is successfully demonstrated in this study for oral cancer detection. This novel clinical approach could be exploited to a robust, high-throughput, and reproducible tool for early cancer detection. Salivary transcriptome profiling can be applied to evaluate its usefulness for other major disease applications as well as for normal health surveillance.

During normal pregnancy, maternal hormones and locally acting cytokines play a key role in regulating the onset of labor, cervical ripening, uterine contraction, and delivery. Maternal infections during pregnancy have been demonstrated to perturb this normal cytokine and hormone-regulated gestation, sometimes resulting in preterm labor, preterm premature rupture of membranes, and preterm low birth weight (PLBW), i.e., < 2,500 g and < 37 weeks of gestation. Our research focus has been to determine whether periodontal infections can provide sufficient challenge to the mother to trigger PLBW. New experiments from 48 case-control subjects have measured gingival crevicular fluid (GCF) levels of PGE(2) and IL-1-beta to determine whether mediator levels were related to current pregnancy outcome. In addition, the levels of 4 periodontal pathogens were measured by using microbe-specific DNA probes. Results indicate that GCF-PGE(2) levels are significantly higher in PLBW mothers, as compared with normal birth weight (NBW) controls (131.4 +/- 21.8 vs. 62.6 +/- 10.3 [mean +/- SE ng/mL], respectively, at P = 0.02). Furthermore, within primiparous PLBW mothers, there was a significant inverse association between birth weight (as well as gestational age) and GCF-PGE(2) levels at P = 0.023. These data suggest a dose-response relationship for increasing GCF-PGE(2) as a marker of current periodontal disease activity and decreasing birth weight. Microbial data indicate that 4 organisms associated with mature plaque and progressing periodontitis--bacteroides forsythus, Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, and Treponema denticola--were detected at higher levels in PLBW mothers, as compared to NBW controls. These data suggest that biochemical measures of maternal periodontal status and oral microbial burden are associated with current PLBW.

Objective Patients with renal failure suffer from symptoms caused by uraemic toxins, possibly of gut microbial origin, as deduced from studies in animals. The aim of the study is to characterise relationships between the intestinal microbiome composition, uraemic toxins and renal failure symptoms in human end-stage renal disease (ESRD). Design Characterisation of gut microbiome, serum and faecal metabolome and human phenotypes in a cohort of 223 patients with ESRD and 69 healthy controls. Multidimensional data integration to reveal links between these datasets and the use of chronic kidney disease (CKD) rodent models to test the effects of intestinal microbiome on toxin accumulation and disease severity. Results A group of microbial species enriched in ESRD correlates tightly to patient clinical variables and encode functions involved in toxin and secondary bile acids synthesis; the relative abundance of the microbial functions correlates with the serum or faecal concentrations of these metabolites. Microbiota from patients transplanted to renal injured germ-free mice or antibiotic-treated rats induce higher production of serum uraemic toxins and aggravated renal fibrosis and oxidative stress more than microbiota from controls. Two of the species, Eggerthella lenta and Fusobacterium nucleatum , increase uraemic toxins production and promote renal disease development in a CKD rat model. A probiotic Bifidobacterium animalis decreases abundance of these species, reduces levels of toxins and the severity of the disease in rats. Conclusion Aberrant gut microbiota in patients with ESRD sculpts a detrimental metabolome aggravating clinical outcomes, suggesting that the gut microbiota will be a promising target for diminishing uraemic toxicity in those patients. Trial registration number This study was registered at ClinicalTrials.gov ( NCT03010696 ).

PURPOSE: This study aims to explore the presence of informative protein biomarkers in the human saliva proteome and to evaluate their potential for detection of oral squamous cell carcinoma (OSCC). EXPERIMENTAL DESIGN: Whole saliva samples were collected from patients (n = 64) with OSCC and matched healthy subjects (n = 64). The proteins in pooled whole saliva samples of patients with OSCC (n = 16) and matched healthy subjects (n = 16) were profiled using shotgun proteomics based on C4 reversed-phase liquid chromatography for prefractionation, capillary reversed-phase liquid chromatography with quadruple time-of-flight mass spectrometry, and Mascot sequence database searching. Immunoassays were used for validation of the candidate biomarkers on a new group of OSCC (n = 48) and matched healthy subjects (n = 48). Receiver operating characteristic analysis was exploited to evaluate the diagnostic value of discovered candidate biomarkers for OSCC. RESULTS: Subtractive proteomics revealed several salivary proteins at differential levels between the OSCC patients and matched control subjects. Five candidate biomarkers were successfully validated using immunoassays on an independent set of OSCC patients and matched healthy subjects. The combination of these candidate biomarkers yielded a receiver operating characteristic value of 93%, sensitivity of 90%, and specificity of 83% in detecting OSCC. CONCLUSION: Patient-based saliva proteomics is a promising approach to searching for OSCC biomarkers. The discovery of these new targets may lead to a simple clinical tool for the noninvasive diagnosis of oral cancer. Long-term longitudinal studies with large populations of individuals with oral cancer and those who are at high risk of developing oral cancer are needed to validate these potential biomarkers.

This article reviews recent reports describing the aetiology of dental trauma from national and international studies as well as the different classifications currently used to report dental injuries. It also discusses possible preventive measures to reduce the increasing frequency of dental trauma. Reported studies demonstrate that males tend to experience more dental trauma in the permanent dentition than females, however, there does not appear to be a difference between the sexes in the primary dentition. Accidents within and around the home were the major sources of injury to the primary dentition, while accidents at home and school accounted for most of the injuries to the permanent dentition. The most frequent type of injury was a simple crown fracture of the maxillary central incisors in the permanent dentition while injuries to the periodontal tissues were more common in the primary dentition. When preventive measures are being planned, knowledge of aetiology is important. More prospective studies from representative populations are required to understand the complexities of dental trauma epidemiology and to allow implementation of preventive strategies to reduce the increasing frequency of dental trauma.

Periodontal disease is a common infection-induced inflammatory disease among individuals suffering from diabetes mellitus. The purpose of this study was to assess the effects of treatment of periodontal disease on the level of metabolic control of diabetes. A total of 113 Native Americans (81 females and 32 males) suffering from periodontal disease and non-insulin dependent diabetes mellitus (NIDDM) were randomized into 5 treatment groups. Periodontal treatment included ultrasonic scaling and curettage combined with one of the following antimicrobial regimens: 1) topical water and systemic doxycycline, 100 mg for 2 weeks; 2) topical 0.12% chlorhexidine (CHX) and systemic doxycycline, 100 mg for 2 weeks; 3) topical povidone-iodine and systemic doxycycline, 100 mg for 2 weeks; 4) topical 0.12% CHX and placebo; and 5) topical water and placebo (control group). Assessments were performed prior to and at 3 and 6 months after treatment and included probing depth (PD), clinical attachment level (CAL), detection of Porphyromonas gingivalis in subgingival plaque and determination of serum glucose and glycated hemoglobin (HbA1c). After treatment all study groups showed clinical and microbial improvement. The doxycycline-treated groups showed the greatest reduction in probing depth and subgingival Porphyromonas gingivalis compared to the control group. In addition, all 3 groups receiving systemic doxycycline showed, at 3 months, significant reductions (P < or = 0.04) in mean HbA1c reaching nearly 10% from the pretreatment value. Effective treatment of periodontal infection and reduction of periodontal inflammation is associated with a reduction in level of glycated hemoglobin. Control of periodontal infections should thus be an important part of the overall management of diabetes mellitus patients.

A direct comparison of quantitative microradiography and microhardness profiles was made using artificial caries-like lesions in human enamel. Tooth crowns with lesions were cut in half through the center of the lesions and opposing halves were assessed by one of the techniques, from the anatomical surface, across the lesion, and into the underlying enamel. A linear relationship was found between volume percent mineral determined by microradiography and the square root of the Knoop Hardness Number assessed by microhardness testing in the mineral range of 40–90 volume percent. The relationship also holds for sound dentine. It is concluded that either technique can be used to measure mineral profiles through carious lesions as a result of demineralization and presumably remineralization.

Mucins are the principal organic constituents of mucus, the slimy visco-elastic material that coats all mucosal surfaces. Compelling evidence suggests that they play an integral role in non-immune protection of the oral cavity. Specific protective functions include: 1) protection against desiccation and environmental insult, 2) lubrication, and 3) antimicrobial effects against potential pathogens. Biosynthesis of mucin is regulated by both intrinsic ("cooperative sequential specificity") and extrinsic ("structural modulation") controls. These controls form the basis by which mucin's structure can be modified to meet a dynamically changing biological need.

BACKGROUND: Vascular endothelial growth factor C (VEGF-C) stimulates tumor lymphangiogenesis (i.e., formation of lymphatic vessels) and metastasis to regional lymph nodes by interacting with VEGF receptor 3 (VEGFR-3). We sought to determine whether inhibiting VEGFR-3 signaling, and thus tumor lymphangiogenesis, would inhibit tumor metastasis. METHODS: We used the highly metastatic human lung cancer cell line NCI-H460-LNM35 (LNM35) and its parental line NCI-H460-N15 (N15) with low metastatic capacity. We inserted genes by transfection and established a stable N15 cell line secreting VEGF-C and a LNM35 cell line secreting the soluble fusion protein VEGF receptor 3-immunoglobulin (VEGFR-3-Ig, which binds VEGF-C and inhibits VEGFR-3 signaling). Control lines were transfected with mock vectors. Tumor cells were implanted subcutaneously into severe combined immunodeficient mice (n = 6 in each group), and tumors and metastases were examined 6 weeks later. In another approach, recombinant adenoviruses expressing VEGFR-3-Ig (AdR3-Ig) or beta-galactosidase (AdLacZ) were injected intravenously into LNM35 tumor-bearing mice (n = 14 and 7, respectively). RESULTS: LNM35 cells expressed higher levels of VEGF-C RNA and protein than did N15 cells. Xenograft mock vector-transfected LNM35 tumors showed more intratumoral lymphatic vessels (15.3 vessels per grid; 95% confidence interval [CI] = 13.3 to 17.4) and more metastases in draining lymph nodes (12 of 12) than VEGFR-3-Ig-transfected LNM35 tumors (4.1 vessels per grid; 95% CI = 3.4 to 4.7; P<.001, two-sided t test; and four lymph nodes with metastases of 12 lymph nodes examined). Lymph node metastasis was also inhibited in AdR3-Ig-treated mice (AdR3-Ig = 0 of 28 lymph nodes; AdLacZ = 11 of 14 lymph nodes). However, metastasis to the lungs occurred in all mice, suggesting that LNM35 cells can also spread via other mechanisms. N15 tumors overexpressing VEGF-C contained more lymphatic vessels than vector-transfected tumors but did not have increased metastatic ability. CONCLUSIONS: Lymph node metastasis appears to be regulated by additional factors besides VEGF-C. Inhibition of VEGFR-3 signaling can suppress tumor lymphangiogenesis and metastasis to regional lymph nodes but not to lungs.

The purpose of the present investigation was to examine the effect of SRP on clinical and microbiological parameters in 57 subjects with adult periodontitis (mean age 47 +/- 11 years). Subjects were monitored clinically and microbiologically prior to and 3, 6 and 9 months after full-mouth SRP under local anaesthesia. Clinical assessments of plaque, redness, suppuration, BOP, pocket depth and attachment level were made at 6 sites per tooth. The means of duplicate attachment level measurements taken at each visit were used to assess change between visits. Clinical data were averaged within each subject and then averaged across subjects for each visit. Subgingival plaque samples were taken from the mesial aspect of each tooth and the presence and levels of 40 subgingival taxa were determined using whole genomic DNA probes and checkerboard DNA-DNA hybridization. The mean levels and % of sites colonized by each species (prevalence) was computed for each subject at each visit. Differences in clinical and microbiological parameters before and after SRP were sought using the Wilcoxon signed ranks test or the Quade test for more than 2 visits. Overall, there was a mean gain in attachment level of 0.11 +/- 0.23 mm (range -0.53 to 0.64 mm) 3 months post-therapy. There was a significant decrease in the % of sites exhibiting gingival redness (68 to 57%) and BOP (58 to 52%) as well as a mean (+/-SEM) pocket depth (3.3 +/- 0.06 to 3.1 +/- 0.05 mm). Sites with pre-therapy pocket depths of < 4 mm showed a non-significant increase in pocket depth and attachment level, 4.6 mm pockets showed a significant decrease in pocket depth and a non-significant gain in attachment post-therapy, while > 6 mm pockets showed a significant decrease in pocket depth and attachment level measurements post-therapy. Significant clinical improvements were seen in subjects who had never smoked or were past smokers but not in current smokers. Mean prevalences and levels of P. gingivalis, T. denticola and B. forsythus were significantly reduced after SRP, while A. viscosus showed a significant increase in mean levels. The mean decrease in prevalence of P. gingivalis was similar at all pocket depth categories, while B. forsythus decreased more at shallow and intermediate pockets and A. viscosus increased most at deep sites. P. gingivalis. B. forsythus and T. denticola were equally prevalent among current, past and never smokers pre-therapy, decreased significantly post-SRP in never and past smokers but increased in current smokers. Clinical improvement post-SRP was accompanied by a modest change in the subgingival microbiota, primarily a reduction in P. gingivalis, B. forsythus and T. denticola, suggesting potential targets for therapy and indicating that radical alterations in the subgingival microbiota may not be necessary or desirable in many patients.

In vitro cellular responses of osteoblast-like cells were studied on titanium surfaces with different surface morphologies. Surface profilometry was used to determine whether rough or smooth surfaces with regular or irregular morphologies can be produced by conventional fabrication techniques. Significantly higher levels of cellular attachment were found using rough, sandblasted surfaces with irregular morphologies. These results correlate with recent in vivo findings and suggest that implants should be prepared with roughened surfaces at bony contact areas.