Effect of extracellular matrix and dental pulp stem cells on bone regeneration with 3D printed PLA/HA composite scaffolds.

The demand for bone grafting procedures in various fields of medicine is increasing. Existing substitutes in clinical practice do not meet all the criteria required for an ideal bone scaffold, so new materials are being sought. This study evaluated bone regeneration using a critical-size Wistar rat's calvarial defect model. 12 male and 12 female rats were evenly divided into 3 groups: 1. Negative and positive (Geistlich Bio-Oss®) controls; 2. polylactic acid (PLA) and PLA/hydroxyapatite (HA); 3. PLA/HA cellularised with dental pulp stem cells (DPSC) and PLA/HA extracellular matrix (ECM) scaffolds. PLA/HA filament was created using hot-melt extrusion equipment. All scaffolds were fabricated using a 3D printer. DPSC were isolated from the incisors of adult Wistar rats. The defects were evaluated by micro-computed tomography (µCT) and histology, 8 weeks after surgery. µCT revealed that the Bio-Oss group generated 1.49 mm3 and PLA/HA ECM 1.495 mm3 more bone volume than the negative control. Histology showed a statistically significant difference between negative control and both (Bio-Oss and PLA/HA ECM) groups in rats of both genders. Moreover, histology showed gender-specific differences in all experimental groups and a statistically significant difference between cellularised PLA/HA and PLA/HA ECM groups in female rats. Qualitative histology showed the pronounced inflammation reaction during biodegradation in the PLA group. In conclusion, the bone-forming ability was comparable between the Bio-Oss and PLA/HA ECM scaffolds. Further research is needed to analyse the effects of ECM and PLA/HA ratio on osteoregeneration.

Synthetic polymeric barrier membrane associated with blood coagulum, human allograft, or bovine bone substitute for ridge preservation: a randomized, controlled, clinical and histological trial.

During the normal healing process, an extraction site may lose significant bone volume, making implant placement problematic. Quantitative evaluations of the amount of bone maintained by socket preservation with various materials are limited. The objective of this study was to evaluate, both clinically and histologically, the extent of alveolar bone preservation by blood coagulum (BC) and the potential additional benefits of bone allograft material (AL) versus the state-of-the-art bovine bone mineral (BB), covered by a polyethylene glycol (PEG) barrier, in extraction socket grafting procedures. Adult patients (n=32) with single-rooted teeth indicated for extraction were treated (45 sites). After atraumatic extraction, the sockets were filled with BC, AL, or BB and covered with a synthetic PEG barrier membrane. Changes in bone height and width were measured clinically and the amount of bone formed and residual graft particles were measured histologically after 6 months. Changes in ridge width at 6 months were -1.5mm for AL versus -2.5mm for BB and -2.3mm for BC. New bone formation amounted to 47.8%, 33.3%, and 28.2% at BC-, AL-, and BB-treated sites, respectively. Using AL with the PEG barrier preserved the ridge width at 6 months better than BB or BC and resulted in similar amounts of bone histologically to BB.

Comparing the efficacy in reducing dentin hypersensitivity of a new toothpaste containing 8.0% arginine, calcium carbonate, and 1450 ppm fluoride to a benchmark commercial desensitizing toothpaste containing 2% potassium ion: an eight-week clinical study in Rome, Italy.

OBJECTIVE: The objective of this double-blind dentin hypersensitivity clinical study was to investigate the effectiveness of a new desensitizing toothpaste containing 8.0% arginine, calcium carbonate, and 1450 ppm fluoride as sodium monofluorophosphate (MFP), compared to that of a benchmark commercially available desensitizing toothpaste containing 2% potassium ion, dosed as 5.0% potassium nitrate, and 1450 ppm fluoride as sodium fluoride (NaF). METHODS: A total of 80 subjects were entered into the study, and stratified into two balanced groups according to their baseline mean tactile and mean air blast sensitivity scores. The two groups were randomly assigned to use either the new arginine toothpaste or the benchmark commercially available desensitizing toothpaste containing 2% potassium ion. Subjects were instructed to brush their teeth twice daily (morning and evening) for one minute with their assigned toothpaste and a commercially available soft-bristled toothbrush. Dentin hypersensitivity examinations, which included tactile and air blast sensitivity measures, were conducted at baseline, one week, two weeks, four weeks, and eight weeks. Subject examinations were conducted by the same dental examiner at each examination period. RESULTS: This clinical study demonstrated that the new toothpaste, containing 8.0% arginine and 1450 ppm fluoride as MFP in a calcium carbonate base, provided a significant reduction in dentin hypersensitivity when used over a period of eight weeks. The study also showed that the new arginine toothpaste provided significantly greater reductions (p < 0.05) in dentin hypersensitivity in response to tactile (38.9%, 28.8%, and 11.6%) and air blast (16.8%, 26.4%, and 33.8%) stimuli than the benchmark commercial desensitizing toothpaste containing 2% potassium ion and 1450 ppm fluoride as NaF in a silica base, after two weeks, four weeks, and eight weeks of product use, respectively. CONCLUSION: A new toothpaste containing 8.0% arginine, calcium carbonate, and 1450 ppm fluoride as MFP provides significantly increased hypersensitivity relief (p < 0.05) as compared to a benchmark commercial desensitizing toothpaste containing 2% potassium ion, dosed as potassium nitrate, after two weeks, four weeks, and eight weeks of product use.

Modifications of periodontal tissues associated with Williams syndrome. A case report.

Williams syndrome, also known as Williams-Beuren syndrome, or elfin-facies syndrome, was described by Dr. Williams and Dr. Beuren for the first time in 1961 and 1962. This multisystem, congenital and panethnic disorder is characterized by a number of developmental and physical abnormalities like excess of gingiva. The goal of this article is to present the application of a protocol of periodontal treatment leading to the functional rehabilitation of the oral areas affected by excess of gingiva. A 19-year-old boy, diagnosed as suffering from Williams Syndrome, was brought to the dental school, University of Cagliari, seeking for orthodontic and periodontal treatment. During the consultation the excess of gingiva needing periodontal treatment was noticed. This report reveals a classic presentation of the syndrome, with emphasis on its oral and periodontal manifestations. Periodontal management included periodontal flap surgery to treat the excess of gingiva performing clinical crown lengthening. Re-evaluation of the patient after two months showed remarkable reduction of the excess of gingiva. Williams syndrome is clinically important to the periodontist, because of its associated features of excess of gingiva. Periodic examinations are recommended to identify any possible recurrence or complications.

Cross-sectional analysis of the implant-abutment interface.

The purpose of this study was to develop a technique to evaluate the implant-abutment gap of an external hexagon implant system as a function of radius. Six implants of 3.75 mm in diameter (Conexao Sistema de Protese Ltda, Sao Paulo, Brazil) and their respective abutments were screw connected and torqued to 20 N cm(-1). The implants were mounted in epoxy assuring an implant long-axis position perpendicular to the vertical axis. Each implant was grounded through its thickness parallel to implant long-axis at six different distance interval. Implant-abutment gap distances were recorded along the implant-abutment region for each section. Individual measurements were related to their radial position through trigonometric inferences. A sixth degree polynomial line fit approach determined radial adaptation patterns for each implant. Micrographs along implant sections showed a approximately 300 mum length implant-abutment engagement region. All implants presented communication between external and internal regions through connection gaps and inaccurate implant-abutment alignment. Average gap distances were not significantly different between implants (P > 0.086). Polynomial lines showed implant-abutment gap values below 10 mum from 0 mum to approximately 250 mum of the implant-abutment engagement region. Gap distances significantly increased from approximately 250 mum to the outer radius of the implant-abutment engagement region. The technique described provided a broader scenario of the implant-abutment gap adaptation compared with previous work concerning implant-abutment gap determination, and should be considered for better understanding mechanical aspects or biological effects of implant-abutment adaptation on peri-implant tissues.

Clinical and microbial evaluation of a histatin-containing mouthrinse in humans with experimental gingivitis.

OBJECTIVE: P-113, a 12 amino acid histatin-based peptide, was evaluated in a mouthrinse formulation for safety, prevention of the development of experimental gingivitis, and for its effects on periodontal flora. METHOD: 159 periodontally healthy subjects abstained from oral hygiene procedures and self-administered either 0.005%, 0.01%, 0.05% P-113 or placebo mouthrinse formulations twice daily over a four week treatment period. During this time, the safety, anti-plaque, and anti-gingivitis effects of P-113 were evaluated. RESULTS: There was a significant reduction in plaque (p=0.046) and a reduction in gingivitis (p=0.086) for subjects using 0.01% P-113 mouthrinse. Significantly more subjects in the 0.01% and 0.05% treatment groups showed a small increase in plaque index of <0.25 as compared to the placebo group (p<0.05). Similar trends were noted for changes in the % of sites with bleeding on probing in the 0.01% P-113 group. There were no treatment-related adverse events, and there were no adverse shifts in supragingival microflora during the study. CONCLUSION: These data suggest that P-113 mouthrinse is safe and reduces plaque, gingivitis and gingival bleeding in the human experimental gingivitis model.

Microbiological findings in prepubertal periodontitis. A case report.

Generalized pre-pubertal periodontitis (GPP) is a rare entity that usually affects children with severe systemic diseases. We report the case of a 7-year-old male patient diagnosed with GPP, with no apparent systemic condition, who lost all his primary teeth to periodontal disease. Before extractions, while he was still in mixed dentition the subgingival plaque was collected and analyzed using DNA probes to 40 different microorganisms. Putative periodontopathogens such as Prevotella intermedia, Selenomonas noxia, Fusobacterium nucleatum, and Actinobacillus actinomycetemcomitans could be identified throughout the mouth. More intriguing was the colonization of the sulcus of some secondary teeth by potentially harmful microorganisms found in pockets of diseased adjacent primary teeth.

Identification of bacterial species on or in crevicular epithelial cells from healthy and periodontally diseased patients using DNA-DNA hybridization.

The purpose of this investigation was to identify bacterial species present on or in crevicular epithelial cells in healthy and diseased sites using DNA probes. In order to achieve this aim, further improvements were made in the separation of unattached bacteria from those adherent to epithelial cells isolated from the human gingival crevice or periodontal pocket. Then the DNA probes were used to determine the prevalence of detectable DNA from 15 microbial species on or in crevicular epithelial cells. One sample was taken from a single subgingival site in each of 51 individuals ranging in age from 19 to 45 years. Samples were taken from 27 sites of clinically healthy subjects and 24 samples were taken from subjects having periodontally diseased sites. DNA-DNA hybridization indicated that a majority of epithelial cells from healthy sites (63%) were in contact with or harbored Streptococcus oralis. On the other hand, species such as Bacteroides forsythus, Prevotella intermedia, Capnocytophaga ochracea and Campylobacter rectus were more frequently detected in elevated numbers in periodontally diseased sites. Cluster analysis of the microbial profiles generally aggregated subjects with and without periodontitis into separate cluster groups. The cluster patterns suggest the possibility that microbial complexes will be, in part, determined by the receptors available on the epithelial cells.

Rapid evaluation of serum and gingival crevicular fluid immunoglobulin G subclass antibody levels in patients with early-onset periodontitis using checkerboard immunoblotting.

A method was developed to evaluate the presence of immunoglobulin G (IgG) subclass (1-4) antibody to Actinobacillus actinomycetemcomitans, serotype b (strain Y4) in patients with early-onset periodontitis on a single nitrocellulose membrane. Sera from 30 early-onset periodontitis patients and gingival crevicular fluid samples from 2 patients were collected and tested with four different preparations of A. actinomycetemcomitans (Y4). The principle steps of the assay are: a) binding of the bacterial antigen (Y4) and the anti-human IgG antibody (capture antibody) in parallel lanes on nitrocellulose membranes; b) incubation of known concentrations of the IgG subclasses 1, 2, 3 and 4, as well as a dilution of serum and/or gingival crevicular fluid from patients in lanes perpendicular to the antigen lanes; c) incubation of the membranes with the corresponding peroxidase conjugated anti-human IgG subclass secondary antibody; d) detection of positive signals by enhanced chemiluminescence. The blots were evaluated by visual comparison to a series of blots containing known concentrations of IgG subclasses. The method was used to rapidly screen a relatively large number of patient sera and gingival crevicular fluid samples for IgG subclasses in a cost-effective assay. The predominant IgG subclass found in early-onset periodontitis was IgG2.

Clinical and microbiological features of subjects with adult periodontitis who responded poorly to scaling and root planing.

In a previous report, it was shown that scaling and root planing (SRP) decreased mean pocket depth and attachment level in subjects with adult periodontitis, as well as the levels and prevalence of Bacteroides forsythus, Porphyromonas gingivalis and Treponema denticola. However, a subset of subjects in that study exhibited mean loss of attachment following SRP. The purpose of the present investigation was to seek clinical and microbiological differences between subjects who responded well or poorly to SRP. 57 subjects with adult periodontitis were treated by full-mouth SRP under local anaesthetic. Clinical assessments of plaque, redness, suppuration, BOP, pocket depth and attachment level were made at 6 sites per tooth prior to and 3 months post-SRP. Attachment level measurements were repeated at each visit and differences in means between visits used to assess change. 18 subjects showed mean attachment loss 3 months post-SRP (poor response group), while 39 showed mean attachment level gain (good response group). The prevalence and levels of 40 subgingival taxa in subgingival plaque samples from the mesiobuccal site of each tooth (maximum 28 sites) in each subject prior to and 3 months post-SRP were assessed using checker-board DNA-DNA hybridization. The prevalence of each species was computed for each subject and averaged across subjects in the 2 treatment-response groups at each visit. Differences between groups were sought using the Mann-Whitney test. There were no statistically significant differences between the 2 response groups in any clinical parameter prior to therapy. Subjects in the good response group showed more attachment level gain at sites with baseline pocket depths of < 4 mm, 4-6 and > 6 mm than poor response subjects. Of 40 species evaluated, A. naeslundii genospecies 2 (A. viscosus), T. denticola, C. gracilis and C. rectus were significantly higher and more prevalent pre-therapy in the good response subjects. Mean attachment level change post SRP could be predicted using multiple linear regression with A. naeslundii genospecies 2 (A. viscosus) and T. denticola as the predictor variables (r2 = 0.373, p < 0.00001). Sites that gained > or = 2 mm of attachment post therapy showed a significant decrease in the counts of P. gingivalis (7.5 +/- 3.5 to 0.2 +/- 0.2 x 10(5)), T. denticola (8.2 +/- 3.5 to 1.8 +/- 1.1 x 10(5)) and B. forsythus (11.1 +/- 5.7 to 0.3 +/- 0.2 x 10(5)). The data of the present investigation indicate that SRP is most effective in subjects and sites with high levels of the subgingival species that this therapy affects.

The effect of SRP on the clinical and microbiological parameters of periodontal diseases.

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.

Children, adolescents and periodontal diseases.

OBJECTIVES: This manuscript attempts to critically review current literature regarding the natural history, aetiology and pathogenesis of the common periodontal diseases to affect children and adolescents. The logic behind the emergence of a new classification in the early 1990s is explained and potential problems with the interpretation of such systems outlined. DATA SOURCES: The manuscript focuses upon recent developments, reported in the international periodontal literature, aimed at unraveling the molecular basis for this group of diseases. The concept of one disease type progressing with time to another disease within the same individual is discussed, and early data presented that indicate the possibility of microbial transmission from deciduous to permanent dentition's within a subject. CONCLUSIONS: It is concluded that differing classification systems for adolescent and childhood periodontal diseases may lead to confusion within the dental profession, unless the clinical and molecular basis for such diseases is fully understood. Further advances in basic research using molecular biology tools should assist in our understanding of the aetiopathology at a molecular level and hopefully lead to the development of new treatment strategies.

Estimation of serum antibody to subgingival species using checkerboard immunoblotting.

Measurement of serum antibody to subgingival bacterial species has been useful in discriminating possible periodontal pathogens and in assessing the host's immune response to subgingival species. An immunoassay system was developed to measure the level of serum antibody to multiple subgingival species in multiple serum samples on a single nitrocellulose membrane. The principle steps of the assay are the following: 1) binding of antigens from bacterial preparations and protein A in parallel lanes on nitrocellulose membranes; 2) incubation of known concentrations of human immunoglobulin as well as various dilutions of serum from patients in lanes perpendicular to the antigen lanes; 3) incubation of the membrane with a peroxidase-conjugated second antibody; 4) detection of positive reactions by enhanced chemiluminescence. Emitted light was captured on a photographic film in which the positive reactions appeared as squares at the intersections of antigens with appropriate antibody. Antibody was quantified using a laser densitometer to compare the signal intensity of unknown samples with the ones generated by known amounts of human immunoglobulin captured on the same membrane. The assay permitted simultaneous screening and/or quantification of antibody in as many as 45 serum samples against up to 45 bacterial species. The mean and standard error of the coefficients of variation for replicates within an assay averaged 7.3 +/- 2.3%. Coefficients of variation of the assay run on different days for serum antibody to a range of subgingival species averaged 10.1 +/- 2.1%. Checkerboard immunoblotting is a simple and rapid immunoassay to permit quantification and/or screening of antibody to multiple subgingival species or antigens in multiple serum samples.

Chemiluminescent assay of alkaline phosphatase in human gingival crevicular fluid: investigations with an experimental gingivitis model and studies on the source of the enzyme within crevicular fluid.

The purpose of this study was to investigate how levels of gingival crevicular fluid (GCF) alkaline phosphatase (ALP) change in relation to levels of plaque and gingival inflammation in 20 adults during a 21 day period of experimental gingivitis. The source of ALP within GCF was also investigated using a repeat sampling protocol; by determining enzyme levels derived from 30 putative periodontal pathogenic and non-pathogenic species; and by examining inhibition profiles from a variety of host and bacterial ALP isoenzymes. Total 30-s GCF ALP levels increased significantly (p < 0.002) during experimental gingivitis and preceded an increase in gingival index (GI) by approximately 7 days. Enzyme levels correlated with GCF volume (R = 0.7; p < 0.0001), but repeat sampling indicated that entry of ALP into the gingival crevice was independent of the rate of fluid flow. Only 5 of the bacterial species investigated produced clearly detectable levels of ALP in culture supernatants, these were P. gingivalis (381), P. intermedia (581), P. nigrescens (8944), Dentin P. gingivalis (TW 471: clinical isolate) and C. ochracea (25). Levamisole inhibition and studies on suspensions of washed plaque demonstrated that host-derived ALP contributed to > 80% of the enzyme in GCF. We conclude that elevated 30-s GCF ALP levels measured using the chemiluminescent assay reported, are detectable before increases in gingival indices and appear to be a better marker of gingival inflammation than ALP concentrations. The major source of ALP within GCF is host derived and in early inflammatory disease is likely to be of polymophonuclear leukocyte origin.

Response to periodontal therapy in patients with high or low levels of P. gingivalis, P. intermedia, P. nigrescens and B. forsythus.

In a previous study, subjects receiving either adjunctive tetracycline or Augmentin showed, on average, more attachment level gain 10 months post-therapy than subjects receiving either Ibuprofen or a placebo, although some subjects in each treatment group showed loss of attachment post-therapy. Since differences in treatment response might have been due to differences in the subgingival microbiota, the response to different therapies in subjects with different pre-therapy subgingival microbiotas was evaluated. 29 subjects exhibiting loss of attachment > 2.5 mm at 1 or more sites during longitudinal monitoring were treated by modified Widman flap surgery at deep sites, subgingival scaling at all other sites and were randomly assigned one of the following agents: Augmentin, tetracycline, ibuprofen or a placebo. Treatment was completed within 30 days, during which time the subject took the assigned agent. Subgingival plaque samples were taken from the mesial surface of each tooth at each visit and evaluated for their content of 14 subgingival species including P. gingivalis, P. nigrescens, P. intermedia and B. forsythus using DNA probes. 18 subjects with mean counts > 10(5) of 2 or more of these 4 species comprised the high test species group; 11 subjects with mean counts > 10(5) of 0 or 1 of the species, the low test species group. Because this was a post-hoc analysis, the number of subjects in some of the treatment/test species groups was small. However, the 8 high test species subjects who received tetracycline showed the most attachment level gain (0.83 +/- 0.20 mm), while the 3 tetracycline-treated, low test species subjects showed minimal gain (0.05 +/- 0.28 mm) 10 months post-therapy. Low test species subjects receiving Augmentin (n = 2) showed a mean gain in attachment of 0.67 (+/- 0.59) mm. The mean % of sites showing either attachment gain or loss > or = 2 mm was computed for each treatment/test species group. High test species subjects receiving tetracycline exhibited the best ratio of gaining to losing sites (16.2), followed by low test species subjects receiving Augmentin (14.1). Periodontal pockets < 7 mm pre-therapy in low test species subjects treated with Augmentin and high test species subjects treated with tetracycline showed attachment gain more frequently than attachment loss. The greatest proportion of gaining sites was seen at pockets > 6 mm, particularly in subjects receiving adjunctive tetracycline. Overall, the data indicated that a gain in mean attachment level post-therapy was significantly associated (p < 0.001) with an increase in C. ochracea accompanied by a decrease in B. forsythus, P. gingivalis, P. intermedia and P. nigrescens. The 4 test species were decreased more in subjects receiving tetracycline. In contrast, Augmentin appeared to be effective in decreasing the % sites colonized by A. actinomycetemcomitans and in increasing the proportion of sites colonized by C. ochracea. Knowledge of the baseline microbiota should improve the choice of an appropriate adjunctive antibiotic for periodontal therapy.

Clinical and microbiological changes associated with the use of 4 adjunctive systemically administered agents in the treatment of periodontal infections.

The purpose of the present investigation was to assess the effects of periodontal surgery and 4 systemically administered agents, Augmentin, tetracycline, ibuprofen or a placebo on clinical and microbiological parameters of periodontal disease. 98 subjects were monitored at 2-month intervals at 6 sites per tooth for clinical parameters. Subgingival plaque samples were taken from the mesial surface of each tooth at each visit and evaluated for their content of 14 subgingival species using DNA probes and a colony lift method. 40 subjects who exhibited loss of attachment > 2.5 mm at 1 or more sites during longitudinal monitoring were treated using modified Widman flap surgery at sites with probing pocket depth > 4 mm, subgingival scaling at all other sites and were randomly assigned 1 of the 4 agents. Treatment was completed within 30 days during which time the subject took the assigned agent. Overall, subjects exhibited a mean attachment level "gain" of 0.34 +/- 0.10 mm (SEM) and a mean pocket depth reduction of 0.62 +/- 0.09 mm 10 +/- 4 months post-therapy. However, certain subjects in each treatment group showed a poor response. Subjects receiving antibiotics exhibited significantly more attachment level "gain" (0.57 +/- 0.15 mm, SEM) than subjects receiving either ibuprofen or a placebo (0.02 +/- 0.10). The differences between Augmentin and tetracycline groups were not significant, nor were the differences between ibuprofen and placebo. 10 months post-therapy, there was a reduction in the number of sites colonized in any subject group by detectable levels (10(3)) of P. gingivalis. Species showing similar reductions were B. forsythus, P. intermedia and P. micros. Subjects receiving systemically administered antibiotics had a significant increase in the proportion of sites colonized by C. ochracea coupled with a greater decrease in the number of sites colonized by P. gingivalis, B. forsythus, P. intermedia and P. micros post-therapy than subjects not receiving antibiotics. The results of this investigation indicate that adjunctive systemic antibiotics increase periodontal attachment "gain" and decrease the levels of some suspected periodontal pathogens in subjects with evidence of current disease progression.

Factors associated with different responses to periodontal therapy.

In a study of the efficacy of modified Widman flap surgery and scaling and root planning accompanied by 1 of 4 systemic adjunctive agents, Augmentin, tetracycline, ibuprofen or placebo, it was observed that subjects differed in their response to therapy. The difference was only partially accounted for by the adjunctive agent employed. The purpose of the present investigation was to examine clinical and microbiological features in subjects who showed different levels of attachment change post-therapy. 40 subjects were subset into 3 groups based on mean attachment level change post-therapy. 10 poor response subjects showed mean attachment loss; 19 moderate response subjects showed mean attachment gain between 0.02-0.5 mm and 11 good response subjects showed a mean gain of attachment > 0.5 mm. Clinical parameters were measured at 6 sites per tooth both pre- and post-therapy. Microbiological samples were taken from the mesial aspect of each tooth and evaluated individually for their content of 14 subgingival taxa using a colony lift method and DNA probes. % of sites colonized by each species was computed for each subject both pre- and post-therapy. Significant differences were observed among treatment response groups for mean probing pocket depth, attachment level and % of sites with plaque pre-therapy. The poor response subjects had the lowest mean probing pocket depth and attachment level, but the highest plaque levels. Post-therapy, the poor response group exhibited the greatest degree of gingival inflammation as assessed by gingival redness and bleeding on probing.(ABSTRACT TRUNCATED AT 250 WORDS)

Subgingival temperature (III). Relation to microbial counts.

The present investigation examined the relationship of selected bacterial species and subgingival temperature. 35 subjects were measured at 6 sites per tooth for clinical parameters and subgingival temperature. Measurements were repeated for 21 subjects at 2 month intervals providing a total of 66 subjects visits. At each visit, subgingival plaque samples were taken from the mesial aspect of each tooth and anaerobically dispersed, diluted and plated on non-selective media. After anaerobic incubation, colonies were lifted to nylon filters and specific species detected using digoxigenin-labeled whole chromosomal DNA probes. Species enumerated were; A. actinomycetemcomitans serotypes a and b, B. forsythus, B. gingivalis, B. intermedius I and II, C. ochracea, F. nucleatum ss. vincentii, P. micros, S. intermedius, S. sanguis I and II, V. parvula and W. recta. Total viable counts and counts of Capnocytophaga sp. were determined directly from the primary isolation plates. A total of 1581 samples were evaluated. Subject visits with higher mean subgingival temperatures had significantly higher mean %s of B. intermedius I and P. micros, and lower mean %s of Capnocytophaga sp. Sites with higher subgingival temperatures had elevated proportions of B. intermedius I and II, A. actinomycetemcomitans serotype a and B. gingivalis more frequently than sites with lower temperatures, while Capnocytophaga sp. were elevated more often at cooler sites. 43 of the subject visits had follow up attachment level measurements at 2 months. The 1026 microbial samples and the subgingival temperature measurements from these visits were related to longitudinal attachment change.(ABSTRACT TRUNCATED AT 250 WORDS)

The use of DNA probes to examine the distribution of subgingival species in subjects with different levels of periodontal destruction.

The present investigation examined the distribution of 14 subgingival species at a total of 2299 sites in 90 subjects with different levels of periodontal destruction. Subgingival plaque samples taken from the mesial aspect of each tooth were anaerobically dispersed, diluted and plated on non selective media. After anaerobic incubation, colonies were lifted to nylon filters and specific species detected using digoxygenin-labeled whole chromosomal DNA probes. The mean total viable count for all sites in all subjects was 8.3 x 10(6). The probes accounted for an average of 27.8% of the total viable count. The % of subjects in which each species was detected was as follows; V. parvula, 98; B. intermedius I, 98; S. sanguis II, 96; B. intermedius II, 95; C. ochracea, 94; B. gingivalis, 91; S. sanguis I, 85; W. recta, 83; F. nucleatum ss. vincentii, 82; S. intermedius, 80; B. forsythus, 76; P. micros, 74; A. actinomycetemcomitans serotype a, 62 and A. actinomycetemcomitans serotype b, 52. The % of sites colonized by each of the 14 test species varied considerably within different subjects. The median number of sites colonized by different species ranged from 3.6% for A. actinomycetemcomitans serotype b to 43.5% for V. parvula. In half the subjects, the mean % of the total viable counts for each of the test species was less than 4%. When subjects were divided on the basis of % of sites at baseline with greater than 3 mm attachment loss, the 14 probes accounted for 29.9% of the microbiota in the localized disease group and 25% in the widespread disease group.(ABSTRACT TRUNCATED AT 250 WORDS)

Relation of baseline microbial parameters to future periodontal attachment loss.

The relationship between the level of subgingival species at baseline and subsequent attachment loss in a subject was examined. 38 subjects (14-71 years) with prior evidence of periodontal destruction were monitored 2x for pocket depth and attachment level at 6 sites per tooth at baseline and 2 months. A subject was considered to exhibit new attachment loss if 1 or more sites increased 3 mm or more in attachment level in 2 months. Subgingival plaque samples were taken at the baseline visit from the mesial aspect of each tooth (28 sites) using Gracey curettes. Samples were dispersed, diluted and plated on Trypticase soy agar supplemented with 5% sheep blood. After 7 days of anaerobic incubation, the colonies were lifted onto nylon filters, lysed and the DNA fixed to the filters. Digoxygenin-labeled DNA probes were used to enumerate 14 subgingival species. 17 of 38 subjects (44.7%) exhibited new attachment loss in 2 months. The % of the total viable count of each species was averaged for each subject. The species enumerated and the mean % of the total cultivable microbiota averaged across the active and inactive subjects were as follows; B gingivalis 2.3, 1.2; W. recta 1.3, 0.6; B. intermedius I 2.5, 2.0; B. forsythus 1.5, 1.2; A. actinomycetemcomitans serotype a 1.1, 0.8; F. nucleatum ss vincentii 1.1, 1.0; S. intermedius 2.0, 1.9; P. micros 1.5, 1.5; B. intermedius II 1.6, 1.7; A. actinomycetemcomitans serotype b 0.4, 0.6; S. sanguis I 1.8, 2.1; S. sanguis II 2.7, 3.0; V. parvula 3.9, 4.2; C. ochracea 0.9, 1.8.(ABSTRACT TRUNCATED AT 250 WORDS)