Showing papers in "Journal of Periodontology in 1993"

Role of Matrix Metalloproteinases in Human Periodontal Diseases.

Abstract: Matrix metalloproteinases (MMP) are a family of proteolytic enzymes that mediate the degradation of extracellular matrix macromolecules, including interstitial and basement membrane collagens, fibronectin, laminin, and proteoglycan core protein. The enzymes are secreted or released in latent form and become activated in the pericellular environment by disruption of a Zn++-cysteine bond which blocks the reactivity of the active site. The major cell types in inflamed and healthy periodontal tissues (fibroblasts, keratinocytes, endothelial cells, and macrophages) are capable of responding to growth factors and cytokines, as well as to products released from the microbial flora by induction of transcription of 1 or more MMP genes. Cytokines that are likely to regulate expression of MMP genes in periodontal tissues include IL-1, TNF-α, and TGF-α. In addition, triggered PMN leukocytes which express only 2 MMP (PMN-CL and Mr 92K GL) release these enzymes from specific granule storage sites in response to a number of stimuli. The evidence that MMP are involved in tissue destruction in human periodontal diseases is still indirect and circumstantial. Cells isolated from normal and inflamed gingiva are capable of expressing a wide complement of MMP in culture and several MMP can be detected in cells of human gingiva in vivo. In addition, PMN-CL and Mr 92K GL are readily detected in gingival crevicular fluid from gingivitis and Periodontitis patients. Osteoclastic bone resorption does not appear to directly involve MMP, but a body of evidence suggests that bone resorption is initiated by removal of the osteoid layer by osteoblasts by means of a collagenase-dependent process. J Periodontol 1993; 64:474-484.

Evidence for Cigarette Smoking as a Major Risk Factor for Periodontitis

Abstract: The role of smoking as a risk factor for periodontitis was assessed separately in diabetic and nondiabetic study groups. Subject listings stratified for age (19 to 40 years) and sex were obtained for subjects with insulin-dependent diabetes mellitus (IDDM) and nondiabetic subjects. For both the IDDM group (n = 132) and the nondiabetic group (n = 95), age and sex stratified samples were constructed by random selection of subjects from each subject listing. Patients were recruited by phone, examined, and their medical and dental histories obtained. Among nondiabetic subjects, the prevalence of periodontitis was markedly higher among current smokers compared with never smokers (P or = 4 mm was higher among current smokers than never smokers (P = 0.001) in the 19 to 30 (8.2% vs. 3.4%) and 31 to 40 (14.3% vs. 4.3%) age groups. The effects of smoking among IDDM subjects were similar to that observed in the nondiabetic population. There were no differences between current and never smokers in the proportion of sites positive for plaque. Attributable risk percents from prevalence data suggest that among nondiabetic subjects, a large proportion, perhaps as much as 51% of the periodontitis in the 19 to 30 year old group and 32% of the periodontitis in the 31 to 40 year old group, is associated with smoking.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of interleukin-8 in inflammation and mechanisms of regulation.

Abstract: Interleukin-8 (IL-8) is a chemoattractant cytokine produced by a variety of tissue and blood cells. Unlike many other cytokines, it has a distinct target specificity for the neutrophil, with only weak effects on other blood cells. Interleukin-8 attracts and activates neutrophils in inflammatory regions. The importance of neutrophil functions has been recognized in periodontal disease for many years. Neutrophils represent the major population of immigrant cells in periodontitis. In diseases with neutrophil dysfunctions periodontal tissue is lost very rapidly. The response of neutrophils to IL-8 is characterized by migration of the cells, the release of granule enzymes, and other intra- and extracellular changes. Connective tissue constituents are efficiently degraded by neutrophil enzymes, released upon activation. Interleukin-8 is a member of the Interleukin-8 supergene family that includes other small chemotactic peptides with structural homology. It also shares with other cytokines DNA sequence features that suggest common regulatory pathways. In vivo intracutaneous application of IL-8 induces local exudation and a massive, long-lasting accumulation of neutrophils. Though IL-8 plays a role in the cytokine network, its major pathophysiological role lies in affecting neutrophils. This article presents a review of literature on the current knowledge of IL-8, its mechanisms of expression, and the effects it exerts on the neutrophil.

Modulation of Host PGE2 Secretion as a Determinant of Periodontal Disease Expression

Abstract: An increasing body of evidence supports the concept that host-produced PGE2 mediates much of the tissue destruction that occurs in periodontal disease. PGE2 levels within the crevicular fluid can serve as a static assessment of ongoing disease activity; i.e., rate of attachment loss and bone resorption. New insights into the mechanisms that regulate PGE2 synthesis provide an altered paradigm of periodontal disease which places the emphasis on host response, rather than the bacterial etiology, as the principal determinant of disease expression. We describe a PGE2 host response model as a hypothetical framework to discuss new, possible explanations for host susceptibility to periodontal disease. J Periodontol 1993;64:432–444.

Current Status of Lasers in Soft Tissue Dental Surgery

Abstract: The aims of this paper are to briefly describe laser physics, the types of lasers currently available for use on soft tissues focusing primarily on CO2 and Nd:YAG laser energies, the histological effects of lasers on oral tissues, laser safety, the clinical applications of lasers on oral soft tissues, and future directions. Of the two types of lasers currently available for dental applications, both the CO2 and Nd:YAG lasers can be used for frenectomies, ablation of lesions, incisional and excisional biopsies, gingivectomies, gingivoplasties, soft tissue tuberosity reductions, operculum removal, coagulation of graft donor sites, and certain crown lengthening procedures. The advantages of lasers include a relatively bloodless surgical and post-surgical course, minimal swelling and scarring, coagulation, vaporization, and cutting, minimal or no suturing, reduction in surgical time, and, in a majority of cases, much less or no post-surgical pain. CO2 lasers, compared to Nd:YAG are faster for most procedures, with less depth of tissue penetration and a well-documented history. There have been recent reports on the use of the Nd:YAG laser for periodontal scaling, gingival curettage, and root desensitization, but further research needs to be conducted. Both the CO2 and the Nd:YAG laser have limited use in conventional flap therapy.

Periodontal regeneration of human intrabony defects. IV. Determinants of healing response.

Abstract: The purpose of this study was to identify factors which might affect the healing response in intrabony defects treated with guided tissue regeneration. Selected sites presented with deep periodontal lesions with 1, 2, and 3 wall combination intrabony component of 6.1 +/- 2.5 mm. The significance of patient, tooth, and defect characteristics and surgical parameters as predictor variables affecting the regenerative outcome before and following the removal of the barrier membrane was assessed. Outcome was measured as tissue gain under the membrane, regenerated probing attachment level (PAL), and bone fill. The total depth of the intrabony component and the radiographic defect angle significantly affected the amount of tissue gain. Seventy-five percent (75%) of the variability of regenerated PAL and bone fill was explained in terms of tissue gain under the membrane, radiographic width of the defect angle, full mouth bleeding score, and presence or absence of flap coverage of the newly formed tissue. Control of the identified predictor variables might improve the extent and predictability of guided tissue regeneration in the treatment of deep intrabony defects.

Periodontal Regeneration of Human Infrabony Defects. I. Clinical Measures

Abstract: A series of investigations was undertaken to evaluate the extent and predictability of periodontal regeneration with barrier membranes in deep infrabony defects. This study reports the clinical outcomes in terms of probing attachment level (PAL) gains, probing pocket depth (PPD) reduction, and recession (REC) of marginal gingiva. Forty deep 1, 2, and 3-wall combination infrabony defects treated with membranes were evaluated 1 year postoperatively following a strict plaque control regimen (mean plaque score = 6.1%, bleeding score = 4% at 1 year). A PAL gain of 6.1 +/- 2.5 mm along with a PPD reduction of 5.9 +/- 2.5 mm were observed. A PAL gain of 2 mm or more was detected in almost 90% of the treated sites. No site lost attachment. Residual PPD was 3 mm or shallower in 95% of the sites. It is concluded that treatment of deep infrabony defects according to the principles of guided tissue regeneration and a strict plaque control regimen represents an efficacious and predictable treatment alternative.

Association between cigarette smoking, bacterial pathogens, and periodontal status.

Abstract: The purposes of this study were to determine if: 1) an association exists between cigarette smoking and signs of periodontal disease after controlling for the confounding variables of age, sex, plaque, and calculus; 2) the prevalence of 5 bacteria commonly associated with periodontal disease differs between smokers and non-smokers; and 3) the presence of any of these bacteria or smoking are associated with a mean proximal posterior probing depth > or = 3.5 mm. Plaque, calculus, gingivitis, and probing depth were measured at the proximal surfaces of all teeth in one randomly selected posterior dental sextant in 615 adults. Subgingival plaque was sampled from the same sites and assayed for the presence of Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, Prevotella intermedia, Eikenella corrodens, and Fusobacterium nucleatum. A subsample of non-smokers (n = 126), who were similar to smokers (n = 63) with respect to age, sex, plaque, and calculus, was randomly drawn from the original sample. These two groups were then compared on the basis of clinical and microbial parameters. The results indicated that the odds of having a mean probing depth > or = 3.5 mm were 5 times greater for smokers than the non-smoker subsample (odds ratio = 5.3; 95% CI = 2.0 to 13.8). No statistically significant difference in the prevalence of any of the bacteria was found between smokers and the non-smoker subsample. Based on logistic regression analyses of each of the 5 bacteria and smoking, mean probing depth > or = 3.5 mm was significantly associated with the presence of A. actinomycetemcomitans, P. intermedia, E. corrodens, and smoking (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Guided Tissue Regeneration Using Bioresorbable and Non-Resorbable Devices: Initial Healing and Long-Term Results

Abstract: Studies on periodontal wound healing have resulted in the development of the treatment modality known as "guided tissue regeneration" (GTR) based on a principle of guiding the proliferation of the various periodontal tissue components during healing following periodontal surgery. The first report of a human tooth treated according to the principle of GTR was presented 10 years ago by Nyman et al. Since then numerous clinical studies and animal experiments have been performed bringing the concept of GTR to a clinical reality. We also know that the results obtained through GTR therapy can be maintained on a long-term basis. The first generation of GTR devices has been non-resorbable, which calls for a second surgical procedure. This is avoided when bioresorbable devices become available. This paper suggests some demands regarding safety and efficacy criteria for both non-resorbable and bioresorbable devices. Results from recent animal experiments and clinical studies following the use of a bioresorbable device in GTR therapy are presented. J Periodontol 1993; 64:1157-1165.

Gingival Recession in Relation to History of Hard Toothbrush Use

Abstract: Gingival recession studies in the U.S. have related primarily to sex and age with little consideration of toothbrush hardness. This preliminary study examined the relation between a history of hard toothbrush use and gingival recession. A total of 182 subjects, male and female, between 18 and 65 years of age, with a minimum of 18 natural teeth, no advanced periodontitis or history of periodontal surgery were examined. Gingival recession was scored as present whenever the free gingival margin was apical to the cemento-enamel junction and root surface was exposed. History of hard toothbrush use was ascertained. Eighty-two subjects had a history of hard toothbrush use, 77 did not, and 23 did not know. The percentage of subjects with recession increased with age from 43% to 81%, with a figure of 63% for all age groups combined. Males tended to show slightly greater levels of recession than females. Regression analysis showed that females had about 4 percentage points less receded surfaces than males. Recession was also found to be more pronounced for subjects with a history of hard toothbrush use, with a mean of 9.4% receded surfaces versus 4.7% for those who had never used a hard brush. For users of hard toothbrushes, the percent of surfaces with recession showed a significant and dramatic increase with increasing brushing frequency; this effect did not exist for those without a history of hard brush use. The relation with age was highly significant, with regression analysis showing that the percent of surfaces with recession tends to increase about 3.5 percentage points per decade.(ABSTRACT TRUNCATED AT 250 WORDS)

1982-1992: a decade of technology development for guided tissue regeneration.

Abstract: In the last decade guided tissue regeneration (GTR) therapy has evolved in both surgical technique and membrane technology. Given new applications and membrane materials, not only must new surgical techniques be critiqued, but membrane designs must be critically examined as well. A review of historical membrane development suggests that 5 design criteria are essential: 1) tissue integration; 2) cell-occlusivity; 3) clinical manageability; 4) spacemaking; and 5) biocompatibility. These criteria may be applied to select appropriate materials and designs for specific GTR applications.

Periodontal Regeneration of Human Infrabony Defects. II. Re-Entry Procedures and Bone Measures

Abstract: This paper evaluates the osseous healing response of 40 infrabony defects treated with guided tissue regeneration. The selected sites presented with deep periodontal lesions with a 1-, 2-, and 3-wall combination infrabony component of 6.1 +/- 2.5 mm. Baseline intrasurgical clinical measurements were compared with intrasurgical clinical measurements obtained at the 1 year surgical re-entry. A significant regeneration of bone of 4.3 +/- 2.5 mm was observed, along with a 0.4 +/- 1.9 mm resorption of the alveolar bone crest, which resulted in a 4.7 mm reduction of the original infrabony defect. Almost 90% of the sites showed a bone gain of 2 mm or more, while no site lost supporting bone; 73 +/- 31.2% of the original defect was filled with bone. The 3- and 2-wall components were filled 95 +/- 6.2% and 82 +/- 18.7% of their original depth, respectively; however, the 1-wall component was filled only 39 +/- 62.4%. It is concluded that treatment of infrabony defects according to the principles of guided tissue regeneration and a strict plaque control regimen resulted in clinically significant and highly predictable bone regeneration.

Periodontal repair in dogs: expanded polytetrafluoroethylene barrier membranes support wound stabilization and enhance bone regeneration.

Abstract: A wound stabilizing effect of expanded polytetrafluoroethylene (ePTFE) membranes was evaluated in supra-alveolar periodontal defects in 5 beagle dogs. The defects, 5 to 6 mm in height, were surgically created around the 2nd, 3rd, and 4th mandibular premolar teeth in contralateral jaw quadrants. The root surfaces were conditioned with heparin, which, in this model, has been demonstrated to compromise periodontal healing and result in formation of a long junctional epithelium. Wound closure included application of ePTFE membranes around each premolar tooth in one jaw quadrant in each dog and flap positioning coronal to the cemento-enamel junction in both jaw quadrants. Healing progressed uneventfully except for 3 teeth in 2 dogs, which experienced membrane exposure. The dogs were sacrificed after a 4-week healing period and tissue blocks were prepared for histometric analysis. Connective tissue repair in heparin+membrane-treated teeth averaged 98% of the defect height compared to 84% in control heparin-treated teeth (P < or = 0.05). Junctional epithelium formation was smaller in membrane-treated teeth than in control teeth (P < or = 0.05) and was usually terminated coronal to the membrane. Bone regeneration was enhanced in membrane-treated teeth compared to controls (P < or = 0.01) and was strongly correlated to the area under the membrane in teeth without membrane exposure (r2 = 0.993; P = 0.002). This correlation was reduced when teeth with membrane exposure were included in the analysis (P < or = 0.05). Cementum regeneration was minimal under both treatment conditions. Root resorption was increased in membrane-treated compared to control teeth (P < or = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Mitogenic effects of growth factors on human periodontal ligament cells in vitro.

Abstract: Periodontal regeneration is thought to require the migration and proliferation of periodontal ligament cells. Evidence suggests that the polypeptide growth factors PDGF, IL-1, and TGF-beta are mediators of these cellular events in wound healing. The purpose of this study was to determine the effects of these growth factors on human periodontal ligament (PDL) cell mitogenesis, and to identify the regulatory influences of TGF-beta on the response to PDGF and IL-1. Confluent, quiescent human PDL cells were cultured in vitro and treated with the polypeptide growth factors PDGF-AA and -BB, IL-1 beta, and TGF-beta in both a dose and time-dependent manner. Mitogenic activity, as a measure of proliferative potential, was determined by the quantitation of 3H-thymidine incorporation during DNA synthesis. The results of this study demonstrated that both PDGF-AA and -BB enhance mitogenic activity in a dose-dependent manner over a concentration range of 1.0 to 50.0 ng/ml. IL-1 beta (0.01 to 1.0 pM) resulted in no mitogenic enhancement, and at high concentrations (10.0 to 100.0 pM) demonstrated an inhibitory effect. TGF-beta produced a significant increase (P < 0.01) in mitogenic activity (although relatively much less than PDGF) in a delayed, bimodal, dose-dependent manner over a concentration range of 0.01 to 20.0 ng/ml, with a maximal response at a concentration of 1.0 ng/ml. Additionally, incubation with TGF-beta at 1.0 ng/ml prior to the addition of PDGF significantly enhanced (P < 0.01) the mitogenic response to both PDGF-AA and PDGF-BB.(ABSTRACT TRUNCATED AT 250 WORDS)

Measurements of Interleukin-6 in Gingival Crevicular Fluid From Adults With Destructive Periodontal Disease

Abstract: This paper describes a study of whether or not the amounts of interleukin-6 (IL-6) in gingival crevicular fluid (GCF) are correlated with periodontal clinical measures. A sensitive ELISA was developed to measure IL-6 in GCF. Two male and 3 female adult subjects with periodontal disease were examined at their first appointments, after 3 months, and after 6 months. Data were obtained on plaque index (PI), bleeding index (BI), probing depth (PD), and on the IL-6 content of GCF samples from 16 sites per subject for a total of 240 measurements. Significant correlations were found between BI and IL-6 (P < 0.005) and between PD and IL-6 (P < 0.05), but not between PI and IL-6. Only 6 out of the 80 sites (in 3 of the 5 subjects) showed PD increases of at least 2 mm. However, for each of these 3 subjects, the amounts of IL-6 in the GCF samples from these sites were markedly higher than the mean amounts of IL-6 in the GCF samples from the remaining sites. These findings suggest that IL-6 may be a useful indicator of periodontal disease, although more extensive longitudinal studies are needed to determine the real clinical value of this GCF component.

Interleukin-1 and bone metabolism: a review.

Abstract: This review discusses the effects of interleukin-1 (IL-1) on bone metabolism and the evidence implicating IL-1 in periodontal disease. IL-1 is a potent cytokine with significant effects on the metabolism of many tissues, including bone. Several in vitro and in vivo studies have established the potent bone-resorbing effect of IL-1. Studies have indicated that IL-1 inhibits bone formation, although it can stimulate formation under certain conditions. Osteoblastic cells are the bone cells expressing IL-1 receptors and responding to IL-1. IL-1 effects on osteoblastic cells include stimulation of prostaglandin formation and modulation of gene expression of several proteins (cytokines, enzymes, enzyme inhibitors, matrix proteins, etc.). Osteoblastic cells also produce IL-1, suggesting an autocrine/paracrine function of IL-1 in bone. IL-1 has been shown to interact with other osteotropic factors, both systemic and local. These interactions modulate the effects of IL-1 on bone. The IL-1 effects on bone metabolism, along with other observations, suggest that IL-1 may be involved in the pathogenesis of bone diseases. Evidence from in vivo and in vitro studies suggests that IL-1 is an important factor in periodontal tissue breakdown. The ability of periodontopathic bacteria to stimulate IL-1 production, the detection of elevated IL-1 levels in periodontally-diseased tissues, and the effects of IL-1 on cells of the periodontium provide a plausible sequence of events in the pathogenesis of periodontal disease. Finally, therapeutic modalities aimed to control the actions of IL-1 are also discussed.

Thick Free Gingival and Connective Tissue Autografts for Root Coverage

Abstract: Studies have shown partial to complete root coverage of denuded root surfaces with the use of thick free gingival autografts (FGGs) or subepithelial connective tissue autografts (CTGs) The purpose of this study was to determine which technique would result in more predictable root coverage of Miller Class I and II marginal tissue recession defects Paired defects in 10 patients were randomly selected for treatment with either the FGG or the CTG With stents as reference points, soft tissue recession was measured with a calibrated probe presurgically and 3 and 6 months postsurgically No significant differences between paired sites in presurgical defect dimensions were found One patient was dropped from the study for noncompliance with postoperative instructions The mean percentage of root coverage for the CTG 3 and 6 months postsurgery for the remaining 9 patients was 78% and 80%, respectively The mean percentage of root coverage for the FGG was 43% at both periods The difference in root coverage between the 2 techniques was significant (P < 003) Complete root coverage was gained in 5 of 9 CTGs but only in one of 9 FGGs Both techniques resulted in a significant improvement in keratinized tissue and probing attachment level, with most of the changes having occurred during the first three months postoperatively Results suggest that the CTG may provide a greater percentage of root coverage than the FGG and that both techniques will effectively increase the width of keratinized tissue

Osteopromotion : a soft-tissue exclusion principle using a membrane for bone healing and bone neogenesis

Abstract: The research reviewed in this paper constitutes a series of investigations intended to develop and evaluate a new membrane technique, which provides improved conditions for osteogenesis during healing of bone defects and restitution of earlier existing bone. The technique has also been shown to aid in bone grafting as well as having the capacity to create new bone for reconstructive purposes. According to this methodology, membranes are utilized to create a space in the tissue in which osteogenesis can occur relatively unimpeded. The paper provides a review of our initial animal experimental work as well as some clinical studies with special emphasis on membrane use in conjunction with dental implants. Possible mechanisms behind the efficacy of the membrane technique are reviewed, and future perspectives of development are also discussed. The osteopromotive membrane technique represents a principally new and major advance in bone biology and reconstructive skeletal surgery. Based on the results obtained by us and by others, the technique is presently utilized clinically in some routine applications. J Periodontol 1993; 64:1116-1128.

Histologic assessment of new attachment following the treatment of a human buccal recession by means of a guided tissue regeneration procedure.

Abstract: A deep, long-standing recession on a mandibular incisor was treated in a 56-year-old female patient. The tooth was tilted buccally and was scheduled for extraction. The recession was 8 mm deep, with a pocket depth of 1 mm and no keratinized tissue. The recession was treated by guided tissue regeneration; the membrane was left in place for 4 weeks. The tooth was extracted along with marginal tissues 5 months after the removal of the membrane. At the time of extraction, 4 mm of root coverage had been achieved and 3 mm of keratinized tissue were measured buccally. Histologic measurements showed that 3.66 mm of new connective tissue attachment had been obtained associated with newly formed cementum (2.48 mm) and bone growth (1.84 mm). The crestal bone level after treatment was located coronal to the preoperative location of the gingival margin.

The Role of the Host Response in Periodontal Disease Progression: Implications for Future Treatment Strategies

Abstract: In this paper, we review the relevant aspects of host responses in periodontal diseases as we understand them today. Discussion will focus on neutrophil function, lymphocytes and the immune response, macrophage function, cytokines and complement, fibroblasts and growth factors, and regeneration. Recent literature and concepts will be presented with an emphasis on future directions and application to treatment regimens. J Periodontol 1993; 64:792-806.

Blocking Periodontal Disease Progression by Inhibiting Tissue-Destructive Enzymes: A Potential Therapeutic Role for Tetracyclines and Their Chemically-Modified Analogs.

Abstract: Tetracyclines (TCs) have wide therapeutic usage as antimicrobial agents; these drugs (e.g., minocycline, doxycycline) remain useful as adjuncts in periodontal therapy. However, TCs also have non-antimicrobial properties which appear to modulate host response. In that regard, TCs and their chemically-modified analogs (CMTs) have been shown to inhibit the activity of the matrix metalloproteinase (MMP), collagenase. The activity of this enzyme appears crucial in the destruction of the major structural protein of connective tissues, collagen. Such pathologic collagenolysis may be a common denominator in tissue destructive diseases such as rheumatoid and osteoarthritis, diabetes mellitus, bullous dermatologic diseases, corneal ulcers, and periodontitis. The mechanisms by which TCs affect and, possibly, diminish bone resorption (a key event in the pathogenesis of periodontal and other diseases) are not yet understood. However, a number of possibilities remain open for investigation including the following: TCs may 1) directly inhibit the activity of extracellular collagenase and other MMPs such as gelatinase; 2) prevent the activation of its proenzyme by scavenging reactive oxygen species generated by other cell types (e.g. PMNs, osteoclasts); 3) inhibit the secretion of other collagenolytic enzymes (i.e. lysosomal cathepsins); and 4) directly affect other aspects of osteoclast structure and function. Several recent studies have also addressed the therapeutic potential of TCs and CMTs in periodontal disease. These drugs reduced excessive gingival collagenase activity and severity of periodontal breakdown in rats infected with Porphyromonas gingivalis and in diabetic rats. Furthermore, the latter drug (CMT) was not associated with the emergence of TC-resistant microorganisms.(ABSTRACT TRUNCATED AT 250 WORDS)

Microbial Composition and Pattern of Antibiotic Resistance in Subgingival Microbial Samples From Patients With Refractory Periodontitis

Abstract: A series of 993 subgingival microbial samples sent to a diagnostic microbiology laboratory included 196 samples that could be identified as compatible with a clinical diagnosis of refractory or recurrent periodontitis. In descending order of prevalence the associated microbiota included Bacteroides forsythus (84%), spirochetes (83%), motile rods (76%), Fusobacterium species (68%), Porphyromonas gingivalis (63%), Campylobacter rectus (47%), Capnocytophaga species (38%), Prevotella intermedia (23%), Peptostreptococcus micros (18%), Actinobacillus actinomycetemcomitans (16%), Candida (14%), enteric rods (9%), Staphylococcus species, not including aureus (5.6%). Eikenella corrodens (3%), Staphylococcus aureus (1.5%), and Enterococcus species (< 1%). Antibiotic resistance to tetracycline, penicillin G, or metronidazole was particularly noticeable for enteric rods, Fusobacterium species, Capnocytophaga species, Staphylococcus, and Actinobacillus actinomycetemcomitans. It was largely absent for Campylobacter rectus. No antibiotic sensitivity data were obtained for Porphyromonas gingivalis or Bacteroides forsythus, as these species were detected by immunofluorescence. The results indicate that a substantial number of microorganisms associated with refractory periodontitis are variably resistant to commonly-used antibiotics. Diagnostic microbiology must be considered an essential adjunct to the therapist faced with periodontal lesions refractory to conventional treatment.

Inhibitory Effect of Tea Catechins on Collagenase Activity

Abstract: A major purpose of this study was to examine inhibitory effect of the catechin derivatives from Japanese green tea Camellia sinensis on collagenase activity. The crude tea catechins, which contain (+)-catechin (C), (-)-epicatechin (EC), (+)-gallocatechin (GC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECg), and (-)-epigallocatechin gallate (EGCg), were tested for their ability to inhibit the prokaryotic and eukaryotic cell derived collagenase activities. Among the tea catechins tested, ECg and EGCg showed the most potent inhibitory effect on collagenase activity when an optimal concentration of tea catechins (100 micrograms/ml) was added to reaction mixture containing collagenase and collagen. Preincubation of collagenase with tea catechins reduced the collagenase activity as well. In contrast to ECg and EGCg, the other four tea catechins (C, EC, EGC, and GC) did not show any collagenase inhibitory effect. Our results suggest that the steric structure of 3-galloyl radical is important for the inhibition of collagenase activity. The collagenase activity in the gingival crevicular fluid from highly progressive adult periodontitis was completely inhibited by the addition of tea catechins. These results demonstrated that tea catechins containing galloyl radical possess the ability to inhibit both eukaryotic and prokaryotic cell derived collagenase.

Periodontal Regeneration of Human Infrabony Defects. III. Diagnostic Strategies to Detect Bone Gain

Abstract: Assessment of actual treatment outcome by simple and available diagnostic tests represents an important aspect in the evaluation of periodontal regenerative procedures. This report focuses on the diagnostic accuracy of different strategies to detect the original extent of bone loss and bone gain in deep vertical defects following guided tissue regeneration. Characteristics of probing attachment level and radiographic bone linear measurements were compared to a gold standard obtained as intrasurgical clinical measurements at baseline and at the 1 year re-entry operation. Radiographic linear measurements underestimated bone loss (CEJ-BD) in 55% of cases while the estimate was within 1 mm in 25% of cases. The goodness of agreement could be significantly described by a general linear model incorporating measures of defect morphology. The original level of bone loss could be best detected by an approach which consisted of adding 1.5 mm to the measured attachment level loss. Such an approach correctly estimated...

Periodontal indices around natural and titanium abutments: a longitudinal multicenter study.

Abstract: This multicenter prospective study on the use of an implant system involved 9 centers and reports on the periodontal aspects after 3 years of observation. A total of 558 implants in 159 patients with 197 bridges all independent from natural teeth were originally included. Because of failures and patient withdrawals the number of implants was reduced to 460 and bridges to 174. The cumulative success rate for implants, starting from implant placement, is 94.3% after 2 years and 93.9% after 3 years indicating a leveling of implant loss. Failures concentrated in patients with a high plaque index. The loss of marginal bone was during the second and third years only 0.03 mm per year as an average while it was 0.4 mm during the first year. There were no reports of intense gingival inflammation in any of the patients and the plaque and gingivitis index behaved similarly around abutments and teeth. The probing pocket depth was significantly reduced over the observation time. The resistance towards marginal bone lo...

Subgingival Minocycline Hydrochloride Ointment in Moderate to Severe Chronic Adult Periodontitis: A Randomized, Double‐Blind, Vehicle‐Controlled, Multicenter Study

Abstract: The safety and efficacy of subgingivally-applied 2% minocycline ointment was evaluated in a randomized, double-blind study of 103 adults with moderate to severe periodontitis. Two groups were compared; one received the test minocycline ointment and the other a vehicle control. Both groups had scaling and root planing at baseline, after which the test or control ointments were applied with an applicator into the periodontal pockets at baseline, and at 2, 4, and 6 weeks. Assessment of clinical response was made by measuring probing depth and probing attachment level and gingival bleeding. These measurements were made at baseline prior to scaling and root planing, and at weeks 4 and 12. Microbiological assessment of the subgingival flora was carried out with DNA probes at baseline, and at weeks 2, 4, 6, and 12 to identify and quantify Porphyromonas gingivalis, Prevotella intermedia, and Actinobacillus actinomycetemcomitans. Subgingival minocycline ointment resulted in statistically significantly greater reduction of P. gingivalis at weeks 2, 4, 6, and 12; P. intermedia at weeks 2, 4, 6, and 12; and A. actinomycetemcomitans at weeks 6 and 12. Probing depth reductions were seen for both groups at weeks 4 and 12; however, this reduction was statistically significantly greater in subjects treated with minocycline ointment. Reduction in gingival index and probing attachment gain were seen in both groups, however, the differences between the groups were not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Non‐Human Primates Used in Studies of Periodontal Disease Pathogenesis: A Review of the Literature

Abstract: The inability to examine initiation and progression of periodontal disease and to assess certain therapies in humans has led to a great interest in the use of animal models in periodontal research. Some of the most prominent animals used are non-human primates. This article reviews the characteristics of non-human primate models in periodontal health, in the transition from health to gingivitis to Periodontitis, and in experimental gingivitis and periodontitis. Where possible, the results of these studies are compared with results from human studies. Only a few studies have compared in detail the anatomy, physiology, immunology, and tissue interactions in monkeys with those of humans. With the exceptions of differences and variations in size of the dentition, the number of each tooth type as well as larger canines, presence of diastemata between anterior teeth, and an edge-to-edge relationship of the incisors, the dental and periodontal anatomy of nonhuman primates seem quite similar to that of humans. Cl...

A Review of Longitudinal Studies That Compared Periodontal Therapies

Abstract: There have been numerous longitudinal periodontal studies that have compared the effects of two or more therapies on various clinical parameters. These studies are reviewed and their results are compiled. Both surgical and non-surgical therapy produced improvement in periodontal health. Surgical therapy tended to create greater short-term probing depth reduction than non-surgical therapy; however, the advantage was lost in some studies over time. In shallow probing depths, surgery produced a greater loss of probing attachment than non-surgical therapy. In deeper probing sites, the short-term results comparing mean probing attachment change following non-surgical and surgical therapy were mixed. In most studies, no long-term differences in mean probing attachment level change were present between non-surgical and surgical therapy. There were no differences between surgical and non-surgical therapy in any of the gingival inflammatory indices.

Marginal Periodontitis and Cytokines: A Review of the Literature

Abstract: Recent research on the immunopathogenesis of marginal periodontitis has focused on cytokines, because these mediators govern biological activities in inflammatory tissue destruction. Several studies have been carried out to elucidate the involvement of cytokines in periodontitis, including cytokine measurements in samples from gingival tissue, gingival crevicular fluid, and in supernatants of stimulated in vitro grown cells from gingival tissue and peripheral blood. The results, summarized in this review, suggest that cytokines are involved in the progress of periodontitis. Furthermore, cytokines may be valuable as markers of tissue breakdown. At the present stage, however, there are difficulties in detecting and quantifying cytokines by immunochemical methods and, in particular, by bioassays. Increased knowledge of the cytokine network may open new pathways of periodontitis treatment by controlling processes involved in tissue breakdown.

Periodontal Status of Women Taking Postmenopausal Estrogen Supplementation

Abstract: The association between supplementary estrogen intake and periodontal and gingival status in a total of 228 women 50 to 64 years of age was examined. Clinical parameters including visible supragingival plaque, subgingival calculus, probing pocket depth, clinical attachment level, alveolar bone height measurements, and number of remaining teeth were measured. Gingival status was recorded as gingival bleeding after gentle manipulation. Selected periopathogens, socio-economic, demographic, smoking habits, and health care variables were assessed. Gingival bleeding was significantly lower in the estrogen supplement group (n = 57) compared to the control group (n = 171) (P = 0.009); the estrogen group also exhibited significantly lower visible plaque levels (P = 0.030) and fewer Capnocytophaga-ssp. (P = 0.032). Dental care was more frequent (P < 0.001), and education levels were higher (P = 0.022) in the estrogen group. To investigate whether differences among the above parameters contributed to the difference in gingival bleeding, an age-adjusted analysis of covariance (ANCOVA) was used. The final ANCOVA indicated non-significant relationships for all parameters examined except estrogen intake (P = 0.044). Women taking estrogen exhibited lower gingival bleeding than the control group after correcting for these factors. The results indicate that estrogen supplementation is associated with less gingival bleeding in women aged 50 to 64, as compared to an age-matched control group.