Effects of topical applications of meclofenamic acid and ibuprofen on bone loss, subgingival microbiota and gingival PMN response in the primate Macaca fascicularis

Oral Microbiome and Gingival Gene Expression of Inflammatory Biomolecules With Aging and Periodontitis

Although data describe the presence and increase of inflammatory mediators in the local environment in periodontitis vs. health in humans, details regarding how these responses evolve in the transition from health to disease, changes during disease progression, and features of a resolved lesion remain unknown. This study used a nonhuman primate model of ligature-induced periodontitis in young, adolescent, adult, and aged animals to document features of inflammatory response affected by age. Rhesus monkeys had ligatures tied and provided gingival tissue biopsy specimens at baseline, 0.5, 1, and 3 months of disease and at 5 months of the study, which was 2 months post-ligature removal for clinically resolved tissues. The transcriptome was assessed using microarrays for chemokine (n = 41), cytokine (n = 45), chemokine receptor (n = 21), cytokine receptor (n = 37), and lipid mediator (n = 31) genes. Limited differences were noted in healthy tissues for chemokine expression with age; however, chemokine receptor genes were decreased in young but elevated in aged samples. IL1A, IL36A, and IL36G cytokines were decreased in the younger groups, with IL36A elevated in aged animals. IL10RA/IL10RB cytokine receptors were altered with age. Striking variation in the lipid mediator genes in health was observed with nearly 60% of these genes altered with age. A specific repertoire of chemokine and chemokine receptor genes was affected by the disease process, predominated by changes during disease initiation. Cytokine/cytokine receptor genes were also elevated with disease initiation, albeit IL36B, IL36G, and IL36RN were all significantly decreased throughout disease and resolution. Significant changes were observed in similar lipid mediator genes with disease and resolution across the age groups. Examination of the microbiome links to the inflammatory genes demonstrated that specific microbes, including Fusobacterium, P. gingivalis, F. alocis, Pasteurellaceae, and Prevotella are most frequently significantly correlated. These correlations were generally positive in older animals and negative in younger specimens. Gene expression and microbiome patterns from baseline were distinctly different from disease and resolution. These results demonstrate patterns of inflammatory gene expression throughout the phases of the induction of a periodontal disease lesion. The patterns show a very different relationship to specific members of the oral microbiome in younger compared with older animals.

Effects of ibuprofen-loaded TiO₂ nanotube dental implants in alloxan-induced diabetic rabbits

Purpose

Some systemic conditions, especially diabetes mellitus (DM), adversely affect dental implant success. This study aimed to investigate the effects of ibuprofen-loaded TiO₂ nanotube (ILTN) dental implants in alloxan-induced diabetic rabbits.

Methods

Twenty-six New Zealand white rabbits were treated with alloxan monohydrate to induce DM. At 2 weeks following DM induction, 3 types of implants (sandblasted, large-grit, and acid-etched [SLA], ILTN, and machined) were placed into the proximal tibia in the 10 rabbits that survived following DM induction. Each type of implant was fitted randomly in 1 of the holes (round-robin method). The animals were administered alizarin (at 3 weeks) and calcein (at 6 weeks) as fluorescent bone markers, and were sacrificed at 8 weeks for radiographic and histomorphometric analyses.

Results

TiO₂ nanotube arrays of ~70 nm in diameter and ~17 μm in thickness were obtained, and ibuprofen was loaded into the TiO₂ nanotube arrays. A total of 26 rabbits were treated with alloxan monohydrate and only 10 rabbits survived. The 10 surviving rabbits showed a blood glucose level of 300 mg/dL or higher, and the implants were placed in these diabetic rabbits. The implant stability quotient (ISQ) and bone-to-implant contact (BIC) values were significantly higher in the ILTN group (ISQ: 61.8, BIC: 41.3%) and SLA group (ISQ: 62.6, BIC: 46.3%) than in the machined group (ISQ: 53.4, BIC: 20.2%), but the difference in the BIC percentage between the SLA and ILTN groups was not statistically significant (P=0.628). However, the bone area percentage was significantly higher in the ILTN group (78.0%) than in the SLA group (52.1%; P=0.000).

Conclusions

The ILTN dental implants showed better stability (ISQ) and BIC than the machined implants; however, these values were similar to the commercially used SLA implants in the 2-week diabetic rabbit model.

Transcriptomic phases of periodontitis lesions using the nonhuman primate model

We used a nonhuman primate model of ligature-induced periodontitis to identify patterns of gingival transcriptomic after changes demarcating phases of periodontitis lesions (initiation, progression, resolution). A total of 18 adult Macaca mulatta (12-22 years) had ligatures placed (premolar, 1st molar teeth) in all 4 quadrants. Gingival tissue samples were obtained (baseline, 2 weeks, 1 and 3 months during periodontitis and at 5 months resolution). Gene expression was analyzed by microarray [Rhesus Gene 1.0 ST Array (Affymetrix)]. Compared to baseline, a large array of genes were significantly altered at initiation (n = 6049), early progression (n = 4893), and late progression (n = 5078) of disease, with the preponderance being up-regulated. Additionally, 1918 genes were altered in expression with disease resolution, skewed towards down-regulation. Assessment of the genes demonstrated specific profiles of epithelial, bone/connective tissue, apoptosis/autophagy, metabolism, regulatory, immune, and inflammatory responses that were related to health, stages of disease, and tissues with resolved lesions. Unique transcriptomic profiles occured during the kinetics of the periodontitis lesion exacerbation and remission. We delineated phase specific gene expression profiles of the disease lesion. Detection of these gene products in gingival crevicular fluid samples from human disease may contribute to a better understanding of the biological dynamics of the disease to improve patient management.

The role of the microbiota in periodontal disease

The last decade has witnessed unparalleled advances in our understanding of the complexity of the oral microbiome and the compositional changes that occur in subgingival biofilms in the transition from health to gingivitis and to destructive periodontal disease. The traditional view, which has held sway for the last 2 decades, that disease is characterized by the outgrowth of a consortium, or consortia, of a limited number of potentially pathogenic organisms, has given way to an alternative paradigm. In this new view, the microbiological changes associated with disease represent whole-scale alterations to the overall microbial population structure and to the functional properties of the entire community. Thus, and in common with other microbially mediated diseases of the gastrointestinal tract, the normally balanced, symbiotic, and generally benign commensal microbiome of the tooth-associated biofilm undergoes dysbiosis to a potentially deleterious microbiota. Coincident with progress in defining the microbiology of these diseases, there have been equally important advances in our understanding of the inflammatory systems of the periodontal tissues, their control, and how inflammation may contribute both to the development of dysbiosis and, in a deregulated state, the destructive disease process. One can therefore speculate that the inflammatory response and the periodontal microbiome are in a bidirectional balance in oral health and a bidirectional imbalance in periodontitis. However, despite these clear insights into both sides of the host/microbe balance in periodontal disease, there remain several unresolved issues concerning the role of the microbiota in disease. These include, but are not limited to, the factors which determine progression from gingivitis to periodontitis in a proportion of the population, whether dysbiosis causes disease or results from disease, and the molecular details of the microbial stimulus responsible for driving the destructive inflammatory response. Further progress in resolving these issues may provide significant benefit to diagnosis, treatment, and prevention.

The Nexus Between Periodontal Inflammation and Dysbiosis

The nexus between periodontal inflammation and the polymicrobial biofilm in the gingival sulcus is critical to understanding the pathobiology of periodontitis. Both play a major role in the etiology and pathogenesis of periodontal diseases and each reinforces the other. However, this nexus is also at the center of a significant conundrum for periodontology. For all mucosal polymicrobial biofilms, the most confounding issue is the paradoxical relationship between inflammation, infection, and disease. Despite significant advances made in both periodontal microbiology and periodontal pathobiology, the issue of which comes first, the inflammatory response or the change to a dysbiotic subgingival microbiota, is still debated. In this paper, we present a model for the pathogenesis of periodontitis based on the central role of inflammation and how this modulates the polymicrobial biofilm within the context of the continuum of health, gingivitis, and periodontitis. We propose a new model termed “Inflammation-Mediated Polymicrobial-Emergence and Dysbiotic-Exacerbation” (IMPEDE), which is designed to integrate into and complement the 2017 World Workshop Classification of Periodontitis.

Pro-resolving mediators in the regulation of periodontal disease

Periodontitis is an inflammatory disease of the supporting structures of the dentition that is initiated by bacteria that form a biofilm on the surface of the teeth. The pathogenesis of the disease is a result of complex interactions between the biofilm and the host response that results in dysbiosis of the microbiome and dysregulation of the inflammatory response. Current data suggest that the excess inflammation associated with periodontitis is due to a failure of resolution of inflammation pathways. In this review, the relationship between inflammation and microbial dysbiosis is examined in the context of pro-inflammation and pro-resolution mediators and their ability to modify the course of disease. The impact of local oral inflammation on systemic inflammation and the relationship of periodontitis to other inflammatory diseases, including type 2 diabetes and cardiovascular disease is reviewed. Active resolvers of inflammation, including the lipoxins and resolvins, show great promise as therapeutics for the treatment of periodontitis and other inflammatory diseases.

Host modulation therapy: An indispensable part of perioceutics

Traditionally, only antimicrobials have been used as the chemotherapeutic modality for the treatment of periodontitis. Though bacteria are the primary etiologic factors of periodontal diseases, yet the extent and severity of tissue destruction seen in periodontitis is determined by the host immuno-inflammatory response to these bacteria. This increasing awareness and knowledge of the host-microbial interaction in periodontal pathogenesis has presented the opportunity for exploring new therapeutic strategies for periodontitis by means of targeting host response via host-modulating agents. This has lead to the emergence of the field of "Perioceutics" i.e. the use of parmacotherapeutic agents including antimicrobial therapy as well as host modulatory therapy for the management of periodontitis. These host-modulating agents used as an adjunct tip the balance between periodontal health and disease progression in the direction of a healing response. In this article the host-modulating role of various systemically and locally delivered perioceutic agents will be reviewed.

Clinical and antibacterial effect of an anti-inflammatory toothpaste formulation with Scutellaria baicalensis extract on experimental gingivitis

It was the aim of the study to evaluate the clinical and antibacterial effect of a dentifrice containing an anti-inflammatory plant extract (SB) versus a placebo (PLA) using an experimental gingivitis model. Forty subjects (20 per group) discontinued all oral hygiene measures for four teeth for a period of 21 days using a shield (to generate a possible gingivitis) while they could brush the other teeth normally. After brushing, the shield was removed and teeth were treated with the randomly assigned toothpaste slurry for 1 min. Löe and Silness gingival index (GI), Silness and Löe plaque index (PI), and biofilm vitality (VF%) were assessed at days 0, 14, and 21, respectively. Subjects of the PLA group developed a GI of 0.82 ± 0.342 (day 14) and 1.585 ± 0.218 (day 21), while the data of the SB group were significantly reduced (0.355 ± 0.243 and 0.934 ± 0.342, p < 0.001). While PI was significantly reduced at all follow-up appointments, reductions in VF reached the level of significance only at day 21. The results suggest that the new toothpaste formulation was able to significantly reduce the extent of gingivitis, plaque development, and vital flora.

Serum from postmenopausal women directs differentiation of human clonal osteoprogenitor cells from an osteoblastic toward an adipocytic phenotype

A consistent observation in osteoporosis is bone volume reduction accompanied by increased marrow adipose tissue. No single cause linking the two phenomena has yet been identified. In a human progenitor cell clone (hOP 7) derived from bone marrow, however, we have demonstrated that rabbit serum can direct differentiation away from an osteoblast lineage to one of adipocytes. We now report on whether human serum has a similar effect. Serum was collected from 10 pre- and 10 postmenopausal women and from the 10 postmenopausal women before and following 6-week hormone replacement therapy (HRT). hOP 7 cells were cultured with the various sera, and after 7-14 days adipocytogenesis was determined by oil red O staining and lipoprotein lipase (LPL) and glycerol 3-phosphate dehydrogenase (G3PDH) expression. Incubation with 10% premenopausal serum led to labeling of 10.9% of cells (P < 0.05) with oil red O, whereas application of 10% postmenopausal serum led to a much larger effect, 43.5% labeling (P < 0.001 with respect to premenopausal serum). Oil red O positivity was accompanied by loss of type I collagen expression and increased LPL and G3PDH expression. HRT did not reverse the adipocytogenic effect of postmenopausal serum. In conclusion, serum from postmenopausal women contains factors that steer hOP 7 bone progenitor cells toward an adipocytic phenotype, irrespective of HRT. The study suggests a role for serum factors in the development of fatty marrow in postmenopausal osteoporosis.

Three-dimensional quantification of alveolar bone loss in Porphyromonas gingivalis-infected mice using micro-computed tomography

BACKGROUND

Animal models are routinely used for the study of the pathogenesis of periodontal disease. However, some of the methods used for evaluating alveolar bone loss are limited to linear or two dimension measurements, while other methods, such as histology, are labor consuming. The present study was designed to evaluate a novel method for assessing the volume of alveolar bone loss in mice and to compare it to the traditional morphometric (linear) technique.

METHODS

Seven- to 8-week-old BALB/c mice were divided into three equal groups of six each; two groups were infected orally with Porphyromonas gingivalis (P. gingivalis) 381 or 53,977, while the third group was used as non-infected control. Forty-two days following infection, serum samples were obtained and maxillae were harvested. Bone loss was evaluated by micro-computed tomography (micro-CT) and by the morphometric technique.

RESULTS

Significant decrease in residual supportive bone volumes (RSBV) was observed in both P. gingivalis-infected groups compared to the control group (P<0.0001). The P. gingivalis 53,977-infected group showed less residual supportive bone volume compared to the P. gingivalis 381-infected group, but there were no significant differences between these two groups. Using the morphometric technique, the differences between the three groups were not found to be statistically significant (P>0.05).

CONCLUSIONS

The present study describes a novel micro-CT technique for volumetric evaluation of alveolar bone loss in mice. This technique is relatively simple and accurate, and due to its high sensitivity, enables the investigator to reduce the number of animals needed in each experimental group.

Host response modulation in the management of periodontal diseases

OBJECTIVE

To review the biological mechanisms and clinical utility of therapeutic modulation of the host response in the management of periodontal diseases.

MATERIAL AND METHODS

A search of MEDLINE-PubMed was performed up to and including December 2004. The search was limited to in vitro, experimental animal and clinical studies published in English. The selection criteria included all levels of available evidence: systematic reviews, randomised-controlled clinical trials, controlled clinical trials, prospective and retrospective cohort studies and case reports of human and experimental animal studies.

RESULTS

Six targets for non-microbial chemotherapeutic intervention were identified. Clinical trials have demonstrated the ability of non-steroidal anti-inflammatory drugs to slow periodontal disease progression. However, recently reported serious adverse effects preclude the use of cyclooxygenase-2 inhibitors as an adjunct to periodontal therapy. Adjunctive use of subantimicrobial dose doxycycline to non-surgical periodontal therapy is beneficial in the management of chronic periodontitis over 12 months. Controversial data exist on the effects of bisphosphonate administration as an adjunct to periodontal therapy. Evidence on modulation of other host mediators including lipoxins, cytokines and nitric oxide synthase is limited to animal research.

CONCLUSION

After validation in long-term clinical trials, adjunctive host modulation therapy may prove advantageous in the management of periodontal diseases.

The effect of a dexibuprofen mouth rinse on experimental gingivitis in humans

OBJECTIVES

The pharmacodynamic properties of ibuprofen are related nearly exclusively to the S(+)enantiomer (dexibuprofen). This study investigated the effect of a 1.5% dexibuprofen mouth rinse in an experimentally induced gingivitis.

MATERIALS AND METHODS

The trial was a randomized, double-blinded, placebo-controlled, two-period and two-sequence parallel group cross-over study in 24 healthy volunteers aged 21-30 years (16 males, eight females). Customized guards were worn during tooth brushing to prevent any plaque removal from the experimental area (first and second pre-molars and molars in one upper quadrant). After 22 days of plaque accumulation, the mouth rinses (1.5% dexibuprofen and placebo) were administered under supervision three times daily (rinsing for 1 min. with 15 ml) for 8 days. The wash-out time between the two study periods was 14 days. Parameters evaluated at days 0, 7, 14, 22, and 30 were the Löe & Silness gingival index (GI) and the Quigley & Hein plaque index (QHI). Data were tested for treatment, period, and carry-over effects (parametric cross-over analysis).

RESULTS

There was no statistically significant difference (p=0.240) in GI between placebo and dexibuprofen. However, the decrease in QHI was significantly greater (p=0.019) with dexibuprofen as compared with the placebo.

CONCLUSION

In the present study, a 1.5% dexibuprofen mouth rinse had no effect on gingivitis whereas an anti-plaque effect was demonstrated.

Therapeutic versus prophylactic plus therapeutic administration of omega-3 fatty acid on endotoxin-induced periodontitis in rats

BACKGROUND

The aim of the present study was 1) to evaluate the possible effects of therapeutic usage of omega-3 fatty acid on the gingival tissue levels of prostaglandin E2 (PGE2), prostaglandin F2alpha (PGF2alpha), platelet activating factor (PAF), and leukotriene B4 (LTB4) in endotoxin-induced periodontitis in rats and 2) to investigate whether prophylactic usage provides any additional benefits to therapeutic doses of omega-3 fatty acid.

METHODS

Experimental periodontitis was induced by repeated injection of Escherichia coli lipopolysaccharide (LPS). Thirty-six adult male Sprague-Dawley rats were divided into four study groups: 1) saline controls; 2) LPS; 3) therapeutic omega-3 fatty acid (TO3); and 4) prophylactic plus therapeutic omega-3 fatty acid (P + TO3) groups. In TO3 group, omega-3 fatty acid was given for 15 days following induction of experimental periodontitis. In P + TO3 group, omega-3 fatty acid was started 15 days before baseline, and then periodontitis was induced at baseline and omega-3 fatty acid was continued for 15 days after baseline. On day 15 after baseline, all rats were anesthetized and sacrificed. PGE2, PGF2alpha, and LTB4 levels in gingival tissue samples were analyzed by enzyme immunoassay and PAF levels were analyzed by radioimmonoassay. Data were evaluated statistically by using parametric tests.

RESULTS

LPS injection resulted in significant amount of bone loss (P<0.05). Neither therapeutic nor prophylactic plus therapeutic administration of omega-3 fatty acid with the doses and duration of therapy used in the present study was effective in preventing endotoxin-induced alveolar bone loss. TO3 group exhibited significant decreases in the gingival tissue levels of PGE2, PGF2alpha, LTB4, and PAF compared to the LPS group (P<0.05). PGE2 and PGF2alpha levels in TO3 group were similar to those of the saline group (P>0.05), while LTB4 and PAF levels were statistically higher than the saline group (P<0.05). Prophylactic plus therapeutic usage of omega-3 fatty acid provided similar levels of all these mediators to those of the saline controls (P>0.05).

CONCLUSIONS

Therapeutic omega-3 fatty acid significantly reduced the gingival tissue levels of PGE2, PGF2alpha, LTB4, and PAF in experimental periodontitis. Furthermore, prophylactic usage of omega-3 fatty acid provided additional beneficial effects to the therapeutic administration by decreasing the gingival tissue levels of these mediators to levels of healthy tissue. These findings should be verified by longitudinal clinical trials investigating clinical and biochemical periodontal parameters to better define the possible role of omega-3 fatty acids in periodontal treatment.

Effect of systemic matrix metalloproteinase inhibition on periodontal wound repair: a proof of concept trial

BACKGROUND

The adjunctive use of matrix metalloproteinase (MMP) inhibitors with scaling and root planing (SRP) promotes new attachment in patients with periodontal disease. This pilot study was designed to examine aspects of the biological response brought about by the MMP inhibitor low dose doxycycline (LDD) combined with access flap surgery (AFS) on the modulation of periodontal wound repair in patients with severe chronic periodontitis.

METHODS

Twenty-four subjects were enrolled into a 12-month, randomized, placebo-controlled, double-masked trial to evaluate clinical, biochemical, and microbial measures of disease in response to 6 months therapy of either placebo capsules + AFS or LDD (20 mg b.i.d.) + AFS. Clinical measures including probing depth (PD), clinical attachment levels (CAL), and bleeding on probing (BOP) as well as gingival crevicular fluid bone marker assessment (ICTP) and microbial DNA analysis (levels and proportions of 40 bacterial species) were performed at baseline and 3, 6, 9, and 12 months.

RESULTS

Patients treated with LDD + AFS showed more potent reductions in PD in surgically treated sites of >6 mm (P<0.05, 12 months). Furthermore, LDD + AFS resulted in greater reductions in ICTP levels compared to placebo + AFS. Rebounds in ICTP levels were noted when the drug was withdrawn. No statistical differences between the groups in mean counts were found for any pathogen tested.

CONCLUSIONS

This pilot study suggests that LDD in combination with AFS may improve the response of surgical therapy in reducing probing depth in severe chronic periodontal disease. LDD administration also tends to reduce local periodontal bone resorption during drug administration. The use of LDD did not appear to contribute to any significant shifts in the microbiota beyond that of surgery alone.

Modulation of clinical expression of plaque-induced gingivitis. III. Response of "high responders" and "low responders" to therapy

AIM

The aim of the present study was to characterize the subject-based clinical behavior of the gingiva in response to a tooth-cleaning regimen in two subpopulations, "high-responder" (HR) and "low-responder" (LR) groups, presenting a different inflammatory response to plaque accumulation.

MATERIAL AND METHODS

The study population comprised of 96 systemically and periodontally healthy subjects, 46 males and 50 females, non-smokers, enrolled in an experimental gingivitis trial. At completion of the experimental gingivitis period (day 21), all subjects were prescribed the same 21-day treatment regimen of amine/stannous fluoride (AmF/SnF(2))-containing toothpaste and mouthrinse. Plaque index (PlI), gingival index (GI), gingival crevicular fluid volume (GCF), and angulated bleeding score (AngBS) were recorded on three selected teeth. Treatment efficacy was evaluated in the overall population as well as in HR and LR groups, separately.

RESULTS

A statistically significant decrease of PlI was observed after treatment (p<0.001), with PlI reversing to baseline levels. Changes in PlI revealed the same trend in both HR and LR groups, without differences between groups. Treatment also resulted in a significant decrease of all gingivitis parameters (p<0.001 for all comparisons). After treatment, GI, AngBS, and GCF were comparable with baseline condition. However, when the two groups were compared, day 42-GCF was significantly higher in the HR group than the LR group.

CONCLUSIONS

A treatment regimen based on mechanical plaque control supplemented with AmF/SnF(2)-containing toothpaste and mouthrinse is effective in reducing plaque accumulation and re-establishing healthy gingival conditions after experimentally induced gingivitis, even in subjects with different inflammatory response to plaque accumulation.

Effect of selective cyclooxygenase-2 inhibition on the development of ligature-induced periodontitis in rats

BACKGROUND

The purpose of this study was to evaluate the effect of a selective cyclooxygenase-2 inhibitor on the progression of alveolar bone loss in an experimental periodontitis model in rats.

METHODS

One hundred eighty (180) Wistar rats were separated into 3 experimental groups. Cotton ligatures were placed at the gingival margin level of lower right first molars. The rats were randomly assigned to one of the following groups that received: a daily oral dose of 10 mg/kg body weight of celecoxib (Ce1); 20 mg/kg body weight of celecoxib (Ce2); or 10 ml/kg of saline solution (C). Serum levels of celecoxib and white blood cell count were determined. Standardized digital radiographs were taken after sacrifice at 3, 5, 10, 18, and 30 days to measure the amount of bone loss around the mesial root surface of the first molar tooth in each rat.

RESULTS

Two-way analysis of variance (ANOVA) indicated that groups treated with celecoxib had significantly less bone loss compared to controls (P < 0.0001) and that there was a significant interaction between treatment with celecoxib and time (P < 0.03). Post-hoc comparisons showed that in both groups treated with celecoxib, the bone loss became significant only after 10 days of ligature placement, while in the control group it was already significant after 5 days. However, differences in mean bone loss between control and Ce1 were significant only at 18 days and, between control and Ce2, at 5 and 18 days. There was no significant difference in bone loss among experimental groups at the end of the experimental period.

CONCLUSION

These data provide evidence that systemic therapy with celecoxib can modify the progression of experimentally induced periodontitis in rats.

Modulation of the host response in periodontal therapy

This paper was prepared by the Research, Science, and Therapy Committee of the American Academy of Periodontology to provide the dental profession an overview of current and potential methods to modulate the host response in the treatment of periodontal diseases. Specifically, it discusses components of periodontal disease pathogenesis (i.e., immune and inflammatory responses, excessive production of matrix metalloproteinases and arachidonic acid metabolites, and regulation of bone metabolism) and their modulation.

Degradable poly(anhydride ester) implants: effects of localized salicylic acid release on bone

Degradable poly(anhydride ester) implants in which the polymer backbone breaks down into salicylic acid (SA) were investigated. In this preliminary work, local release of SA from the poly(anhydride esters), thus classified as 'active polymers', on healthy bone and tissue was evaluated in vivo using a mouse model. Degradable polyanhydrides that break down into inactive by-products were used as control membranes because of their chemical similarity to the active polymers. Small polymer squares were inserted over the exposed palatal bone adjacent to the maxillary first molars. Active polymer membranes were placed on one side of the mouth, control polymers placed on the contra lateral side. Intraoral clinical examination showed that active polymer sites were less swollen and inflamed than control polymer sites. Histopathological examination at day 1 showed essentially no difference between control and active polymers. After 4 days, active polymer sites showed epithelial proliferation to a greater extent than the polyanhydride controls. After 20 days, active polymer sites showed greater thickness of new palatal bone and no resorptive areas, while control polymer sites showed less bone thickness as well as resorption including lacunae involving cementum and dentine. From these preliminary studies, we conclude that active polymers, namely poly(anhydride esters), stimulated new bone formation.

Serum fatty acid imbalance in bone loss: example with periodontal disease

Among the numerous factors of bone remodelling, the local action of arachidonic acid metabolites together with cytokines, is particularly important, especially that of prostaglandin PGE2. It has been suggested that the alveolar bone destruction in periodontal disease and osteoporosis can be treated by reducing the ratio of arachidonic acid in phospholipids, which would diminish prostaglandin production. The aim of this study was to evaluate the main serum polyunsaturated fatty acids and a possible alteration in the level of arachidonic acid in patients suffering from periodontal bone loss. Of the 105 patients who participated the study, 78 were suffering from periodontal bone loss and 27 served as a control group. The fatty acids were measured in serum by gas-chromatography. The results showed that the level of fatty acids of the n-6 pathway was higher in our patients with bone loss than in the control group, whereas the reverse was observed with fatty acids of the n-3 pathway. In conclusion, our patients' bone losses are linked with an imbalance between n-6 and n-3 fatty acids, which seems to justify a diet increase in 20- and 22-carbon fatty acids.

Over-the-counter analgesics and antipyretics: a critical assessment

BACKGROUND

It is just 100 years since the introduction of aspirin to medicine. Since then, aspirin and its derivatives have been joined by acetaminophen, and the nonsteroidal anti-inflammatory drugs--ibuprofen, naproxen sodium, and ketoprofen--as the only over-the-counter (OTC) agents approved by the US Food and Drug Administration for the short-term treatment of pain, headache, dysmenorrhea, and fever. Recently the prescription use of aspirin has expanded to include a number of antiplatelet indications.

OBJECTIVE

The purpose of this paper is to review critically the history, mechanisms of action, efficacy, and tolerability of OTC analgesic and antipyretic products. Relatively new and potential future indications for these drugs are also discussed.

CONCLUSION

Although all of the OTC analgesic/antipyretic agents seem to share a common mechanism of prostaglandin inhibition, there are important differences in their pharmacology, efficacy, and side-effect profiles. Considering their often-unsupervised use, the risk-benefit ratio of this class of drugs has been extremely favorable. However, when used inappropriately, even these drugs pose significant risks to certain patient populations.

Blockade of RAGE suppresses periodontitis-associated bone loss in diabetic mice

Diabetes is associated with increased prevalence, severity, and progression of periodontal disease. To test the hypothesis that activation of RAGE (Receptor for Advanced Glycation End products) contributes to the pathogenesis of diabetes-associated periodontitis, we treated diabetic mice, infected with the human periodontal pathogen Porphyromonas gingivalis, with soluble RAGE (sRAGE). sRAGE is the extracellular domain of the receptor, which binds ligand and blocks interaction with, and activation of, cell-surface RAGE. Blockade of RAGE diminished alveolar bone loss in a dose-dependent manner. Moreover, we noted decreased generation of the proinflammatory cytokines TNF-alpha and IL-6 in gingival tissue, as well as decreased levels of matrix metalloproteinases. Gingival AGEs were also reduced in mice treated with sRAGE, paralleling the observed suppression in alveolar bone loss. These findings link RAGE and exaggerated inflammatory responses to the pathogenesis of destructive periodontal disease in diabetes.

Effects of 0.12% chlorhexidine gluconate on experimental gingivitis in non-human primates: clinical and microbiological alterations

OBJECTIVE

This study examined the efficacy of 0.12% chlorhexidine gluconate (Peridex) to reduce gingival inflammation in the absence of mechanical hygiene and its effect on the oral microbial ecology in a non-human primate (NhP) model of gingivitis.

DESIGN

Twelve NhP were stratified based on existing inflammation into two groups of six NhP per group. Oral hygiene was performed on both groups so as to reach a level of gingival health (BOP < or = 0.3) at the conclusion of the hygiene phase. One group received 30 ml of 0.12% chlorhexidine gluconate twice daily 7 days/week, and a second group received 30 ml of placebo (distilled water colored to match the active) using the same regimen for 10 weeks. MEASUREMENT OUTCOMES: Clinical parameters including plaque (PLI), pocket depth (PD), attachment level (AL), and bleeding on probing (BOP) were evaluated at 2-week intervals. Subgingival plaque samples were collected by paper point at 2-week intervals and cultured for predominant cultivable bacteria.

RESULTS

By week 2, there was a difference in BOP between the groups, which reached statistical significance by week 4. This difference in BOP was maintained throughout the course of the study. Chlorhexidine gluconate (0.12%) had no significant effect on PLI, PD, or AL; although PD was greater in the placebo group after week 2 and throughout the study. Microbiologically, at week 4, the treatment group had a reduction in total bacterial counts, as well as Gram positive bacteria, and total black pigmented bacteria, compared to the placebo group. However, only the differences in Actinomyces spp. reached significance. Interestingly, when both groups received only one treatment/day on the weekends (i.e., day 6 and 7), an associated loss of statistically significant differences between the two groups was observed. Additional experiments dosing the non-human primates once daily, 5 days/week yielded no significant differences in clinical parameters, including bleeding, when compared with the placebo group.

CONCLUSION

Non-human primates provided a model system of gingivitis for testing antimicrobial agent effects on the subgingival ecology and accompanying inflammatory responses. Chlorhexidine gluconate (0.12%), even in the absence of mechanical hygiene, was effective in inhibiting clinical signs of inflammation, associated with alterations in the subgingival microbial ecology, most notably Actinomyces spp.

Effects of ketorolac tromethamine mouthrinse (0.1%) on crevicular fluid prostaglandin E2 concentrations in untreated chronic periodontitis

The effects of topical ketorolac tromethamine mouthrinse (0.1%) on gingival crevicular fluid (GCF) prostaglandin E2 (PGE2) concentrations were investigated in a 6-week, randomized, double-blind, placebo-controlled, parallel group, single center study of 42 patients with moderately advanced chronic adult periodontitis. Following screening, GCF was sampled from 6 sites per subject with filter paper strips and PGE2 levels measured using an enzyme immunoassay kit. Only those subjects with mouth median GCF PGE2 concentrations >30 ng/ml entered the rinsing phase. Eligible subjects were allocated placebo rinse in the first 2-week period (days 0 through 14), either ketorolac rinse (test group, n = 21) or placebo rinse (control group, n = 21) in the second 2-week period (days 14 through 28), and placebo rinse in the third 2-week period (days 28 through 42). Full mouth median GCF PGE2 concentrations were calculated for each subject at days 0, 14, 28, and 42, and group means were compared. From day 0 to day 14, no significant changes in GCF PGE2 concentrations were detected in either study group (P > 0.05). Utilizing mean GCF PGE2 concentrations at days 0 and 14 as covariates, no significant differences were observed in adjusted mean PGE2 levels at days 28 and 42 between the study groups (ANCOVA, P > 0.05). A statistically significant increase in GCF PGE2 levels was noted at days 28 and 42 in the placebo group (P < 0.01), but not in the ketorolac group (P > 0.05), when compared to baseline, however. GCF PGE2 levels were further studied in a subset of volunteers (n = 11) during a 12-hour period following first rinsing with mouthrinse (active or placebo) at day 14. GCF was sampled 0, 2, 4, 6, 8, and 12 hours post-rinsing. Mean PGE2 levels were higher in the placebo subgroup than in the ketorolac subgroup, and increased gradually over the 12-hour period in both subgroups. These data indicate that 1) 14 days of rinsing with 0.1% ketorolac mouthrinse controlled the elevation of GCF PGE2 observed in the placebo group but did not actually reduce GCF PGE2 concentrations and 2) changes in GCF PGE2 levels were not detectable in the 12-hour period following first rinsing with ketorolac.

Effect of the NSAID flurbiprofen on remodelling after periodontal surgery

The aim of the present experiment was to assess the effect of the administration of the NSAID flurbiprofen (Froben) on tissue healing after periodontal surgery. Sites from patients with the same treatment modality (modified Widman flap) but receiving a placebo drug and sites within each patient not exposed to surgery served as controls. Nineteen patients suffering from moderate to severe periodontal disease were recruited and they signed informed consent forms. These patients required periodontal surgery as assessed at the periodontal re-evaluation. The sites chosen for the study were all diagnosed with PPD > or = 5 mm and were bleeding on probing. During the healing phase 10 patients received 50 mg Froben 3 times per day for 30 d whereas 9 patients received a placebo drug. Two sites with PPD > or = 5 mm after initial therapy and bleeding on probing served as surgical sites, whereas 2 similar sites were not exposed to surgery. The study design was set up double-blind. The radiographic examination consisted of 2-4 standardized vertical bitewings obtained at the periodontal re-evaluation (BL) at 1, 3 and 6 months post-surgically for digital subtraction and computer assisted densitometric image analysis (CADIA). The regions of interest analysed were mesial or distal crestal sites. Minimal remodelling activity was observed radiographically after periodontal surgery in both patient groups. There were no statistically significant differences between the four groups of sites regarding the mean changes in density when analysing the pairs of radiographs 0-1, 0-3, 0-6 months. A frequency analysis was performed to list the number of sites with different ranges of density change. No differences in the distributions of the numbers of sites were observed when comparing the 4 site groups (Kolmogorov-Smirnov, p > 0.05). A significant reduction of the probing pocket depth and a significant amount of clinical attachment gain was noted at the surgically treated sites irrespective of whether the patients had used flurbiprofen or placebo. Whereas the pathways leading to bone resorption in periodontally diseased sites have been shown, in other studies, to be influenced by NSAID, the results of the present study could not justify general administration of Froben for the purpose of reduction of bone resorption after periodontal surgical procedures in patients with adult periodontitis.

The effect of ketoprofen creams on periodontal disease in rhesus monkeys

Ketoprofen creams were evaluated for the treatment of periodontal disease in a placebo-controlled, double-blind study in the rhesus monkeys, Macaca mulatta. Two formulations containing ketoprofen (1%), with or without vitamin E, were evaluated against appropriate controls (8 monkeys per group). Two weeks prior to treatment, the animals received prophylaxis on only the left side of the mouth (spontaneous model). Selected teeth on the right side of the mouth were ligated (ligature model). The creams were administered to the gingiva once daily at a standard dose of 1.8 ml per monkey for 6 months. Clinical assessments were made 2 wk before initiation, at baseline and 1, 2, 3 and 6 months post-treatment. The clinical parameters included plaque formation, gingival redness, edema, bleeding on probing and Ramfjord Attachment Level measurements (RAL). Radiographs were taken at 2 wk before initiation, baseline and at 3 and 6 months post-treatment. Digital, subtraction radiography was used to measure vertical linear bone loss along the interproximal root surfaces of the left and right mandibular first molars. Gingival crevicular fluid (GCF) was collected for biochemical assays on PGE2, TxB2, LTB4, IL-1 beta and TNF alpha. There were no significant differences among groups with respect to gingival indices. Radiographic data demonstrated significant positive effects on bone activity in both groups treated with ketoprofen formulations with improvement over time in the ligature model (0.01 < or = p < or = 0.04). The placebo group exhibited bone loss of 1.96 +/- 0.48 and 1.40 +/- 0.56 mm per site at 3 and 6 months, respectively. The group treated with ketoprofen cream showed an apparent bone gain of 0.28 +/- 0.41 and 0.78 +/- 0.47 mm per site at 3 and 6 months, respectively. The group treated with ketoprofen cream containing vitamin E showed a mean bone loss of 0.41-0.48 mm per site at 3 months with improvement to an apparent bone gain of 0.31 +/- 0.44 mm per site at 6 months. The biochemical data demonstrated early and significant suppression of GCF-LTB4 by both ketoprofen formulations at 1 month, which preceded the significant suppression of GCF-PGE2 at 2 and 3 months in the ligature model (p < 0.003) and at 2 to 6 months in the spontaneous model (p < 0.02). We conclude that ketoprofen at 1% level in suitable topical vehicles can effectively inhibit GCF-LTB4 and GCF-PGE2 and positively alter alveolar bone activity in the ligature-induced model of periodontitis in the monkey.

Advanced imaging methods

Recent developments in imaging sciences have enabled dental researchers to visualize structural and biophysical changes effectively. New approaches for intra-oral radiography allow investigators to conduct densitometric assessments of dento-alveolar structures. Longitudinal changes in alveolar bone can be studied by computer-assisted image analysis programs. These techniques have been applied to dimensional analysis of the alveolar crest, detection of gain or loss of alveolar bone density, peri-implant bone healing, and caries detection. Dental applications of computed tomography (CT) include the detailed radiologic anatomy of alveolar processes, orofacial soft tissues and air spaces, and developmental defects. Image analysis software permits bone mass mineralization to be quantified by means of CT data. CT has also been used to study salivary gland disease, injuries of the facial skeleton, and dental implant treatment planning. Magnetic resonance imaging (MRI) has been used extensively in retrospective and prospective studies of internal derangements of the temporomandibular joint. Assessments based on MRI imaging of the salivary glands, paranasal sinuses, and cerebrovascular disease have also been reported. Magnetic resonance spectroscopy (MRS) has been applied to the study of skeletal muscle, tumors, and to monitor the healing of grafts. Nuclear imaging provides a sensitive technique for early detection of physiological changes in soft tissue and bone. It has been used in studies of periodontitis, osteomyelitis, oral and maxillofacial tumors, stress fractures, bone healing, temporomandibular joint, and blood flow. This article includes brief descriptions of the technical principles of each imaging modality, reviews their previous uses in oral biology research, and discusses potential future applications in research protocols.

Local and systemic chemotherapy in the management of periodontal disease: an opinion and review of the concept

Periodontal disease appears to arise from the interaction of pathogenic bacteria with a susceptible host. The main aims of disease management have been to establish a high standard of oral hygiene and to professionally and thoroughly debride the root surface Chemical agents could be considered for both aspects of management. Chemoprevention using supragingivally delivered agents such as chlorhexidine may be questioned for value in the pre-treatment hygiene phase but have well-established efficacy immediately preoperatively and during the post-operative weeks. Long-term maintenance use of chlorhexidine is problematic due to local side effects. Antiplaque toothpastes show modest benefits to gingivitis but are not proven to prevent recurrence of periodontitis. Chemotherapy may be directed at subgingival plaque, using antimicrobials, or at the host response using anti-inflammatory agents. Antimicrobials can be locally or systemically delivered. In most cases antimicrobial chemotherapy should be considered adjunctive to mechanical debridement. The advantages of local and systemic chemotherapy must be balanced against the disadvantages and potential side effects of agents. Antimicrobial chemotherapy offers little or no benefit to the treatment of most chronic adult periodontitis patients and should be reserved for the more rapid or refractory types of disease, and after the debridement phase. Despite the large number of studies there are insufficient comparative data to support any one local delivery system or systemic regimen as superior to another. Systemic versus local antimicrobials have not been compared to date. Host response modifying drugs such as non-steriodal anti-inflammatory drugs (NSAIDS) offer the potential to reduce breakdown and promote healing, including bone regeneration. However until more data are available, NSAIDs should not be used in the management of chronic periodontal diseases, there being no specific agent(s) or regimen established for use. Chemotherapy has an important place in the management of chronic periodontal diseases but routine use must be considered as an over prescription of these valuable agents.

Agents with periodontal regenerative potential regulate cell-mediated collagen lattice contraction in vitro

A variety of pharmaceutical agents has been proposed for use in periodontal therapy to inhibit loss of alveolar bone and to promote regeneration of tissues lost to disease. The purpose of this study was to determine the effects of such agents on periodontal cell-mediated gel contraction, an in vitro process considered representative of wound contraction and remodeling in vivo. Human gingival fibroblasts were cultured in a type I collagen lattice, and contraction was quantified by means of a computer-assisted video imaging system. Cell-gel combinations were prepared with cells both pre-exposed and non-exposed to agents; non-anchored cell-gels were then incubated with agents for various time periods. Agents tested included Demecolcine (an inhibitor of cytoskeletal contraction), growth factors (i.e., TGF-beta 1, PDGF, and IGF-1), and non-steroidal anti-inflammatory drugs (NSAIDs) (indomethacin, ibuprofen, naproxen, and flurbiprofen). While Demecolcine inhibited gel contraction, TGF-beta 1 (1-20 ng/mL), PDGF (100 ng/ML), IGF-1 (1000 ng/mL), and [PDGF + IGF], all of which have been reported to enhance wound healing in vivo, promoted lattice contraction in this system. In contrast, NSAIDs inhibited cell-gel contraction. Ethanol, used to solubilize two specific NSAIDs, also inhibited cell proliferation and gel contractile ability, even at very low concentrations. These findings indicate that periodontal cells respond differently to various agents in vitro and may be adversely affected by alcohol. Furthermore, the results of this study suggest that the cell-lattice contraction system holds potential as a method for screening agents for positive or negative effects on cell activity.

Adjunctive supragingival irrigation with acetylsalicylic acid in periodontal supportive therapy

To assess the clinical efficacy of adjunctive supragingival irrigation with buffered 0.3% acetylsalicylic acid (ASA), 60 patients with periodontitis receiving supportive periodontal therapy were randomly assigned to 1 of 3 home regimens: (1) 1x daily adjunctive supragingival irrigation with 300 ml water immediately followed by 200 ml of buffered 0.3% ASA; (2) 1x daily adjunctive supragingival irrigation with 500 ml water; or (3) normal oral hygiene alone. Clinical parameters were assessed at baseline and 6 months. Irrigator use was measured by timers built into the irrigator units. Results at 6 months showed that both supragingival irrigation with buffered 0.3% ASA and supragingival irrigation with water significantly reduced gingival index scores (median 0.1 and 0.35, respectively) and pocket probing depths (both median 0.26 mm) compared to the control group. In addition, irrigation with water resulted in a significant reduction in bleeding on probing (median 0.13), whereas irrigation with buffered 0.3% ASA had no significant effect on bleeding on probing compared to the control group. The clinical efficacy of irrigation with either ASA or water was found to be positively correlated to initial disease severity and irrigator use. Thus, frequent supragingival irrigation with either 0.3% ASA or water in addition to regular oral hygiene appears to be a beneficial adjunct to periodontal supportive therapy in patients with moderate to severe signs of periodontitis. However, the use of buffered 0.3% ASA as an irrigant does not seem to enhance the clinical efficacy of supragingival irrigation on periodontal health.

A comparison of topical ketorolac, systemic flurbiprofen, and placebo for the inhibition of bone loss in adult periodontitis

Systemic non-steroidal anti-inflammatory drugs (NSAIDs) have been shown to reduce alveolar bone loss in periodontitis. This study assesses the efficacy of a topical NSAID rinse, containing ketorolac tromethamine as the active agent. Adult periodontitis patients (n = 55) were studied in this 6-month randomized, double blind, parallel, placebo and positive-controlled study. Each patient had a least 3 sites at high risk for bone loss as assessed by low dose bone scan. Groups, balanced for gender, were assigned to one of three regimens: bid ketorolac rinse (0.1%) with placebo capsule; 50 mg bid flurbiprofen capsule (positive control) with placebo rinse; or bid placebo rinse and capsule. Prophylaxes were provided every 3 months. Monthly examinations assessed safety, gingival condition, and gingival crevicular fluid PGE2. Standardized radiographs were taken at baseline and at 3 and 6 months for digital subtraction radiography. A significant loss in bone height was observed during the study period in the placebo group (-0.63 +/- 0.11; P < 0.001), but not in the flurbiprofen (-0.10 +/- 0.12; P = 0.40) or ketorolac rinse (+0.20 +/- 0.11 mm; P = 0.07) groups. Nested ANOVA revealed that ketorolac and flurbiprofen groups had less bone loss (P < 0.01) and reduced gingival crevicular fluid PGE2 levels (P < 0.03) compared to placebo. ANOVA suggests (P = 0.06) that ketorolac rinse preserved more alveolar bone than systemic flurbiprofen at the dose regimens utilized. These data indicate that ketorolac rinse may be beneficial in the treatment of adult periodontitis.

Preventive therapy for periodontal diseases

Rational approaches to the prevention of destructive periodontitis should be based on a clear understanding of etiology and pathogenesis. However, we are dealing with a heterogeneous family of diseases in which different factors operate. It is an oversimplification to regard poor oral hygiene, and hence an accumulation of non-specific dental bacterial plaque, as the major risk factor. Epidemiological evidence indicates that host factors are likely to be of overriding importance for the most severe forms. The limitations of nonspecific plaque control are therefore discussed. Specific inhibitors of virulence factors provide a logical approach, but their clinical application awaits improved knowledge. Improvement of general health and resistance to disease by proper nutrition, the avoidance of intercurrent disease, and elimination of smoking and stress-induced risk are encouraged. The genetic basis of susceptibility to periodontitis is increasingly understood, and, while gene therapy is not likely to be a practicable approach to prevention, genetic markers of risk are emerging.

Effect of chlorhexidine (0.12%) rinses on periodontal tissue healing after tooth extraction. (II). Radiographic parameters

The aim of the present study was to assess the influence of a 1-month period of chlorhexidine digluconate (CHX) rinses on the remodelling activity of periodontal tissues adjacent to an extraction wound. From 12 patients assigned to the test group rinsing 2 x daily with 15 ml of 0.12% CHX solution (Peridex) starting 2 days after tooth extraction and from 11 patients assigned to the control group rinsing with a placebo solution, standardized radiographs were available taken immediately after tooth extraction and 1, 2, 3 and 6 months thereafter. Computer assisted densitometric image analysis (CADIA) was applied in order to quantify changes in density during the healing phase after tooth extraction. Regions of interest (ROI) were chosen for CADIA covering supracrestal periodontal soft tissue adjacent to the extraction wound. ROIs were also defined on crestal alveolar bone adjacent to the extraction wound. In the active group, 15/20 sites demonstrated an increase in alveolar bone density between months 1 and 6 (mean CADIA value 6.7 +/- 10.0), whereas in the control group 11/21 sites demonstrated a loss in density (mean CADIA values -1.4 +/- 10.5). Similar observations were made when the ROIs covering supracrestal periodontal tissues were analyzed (mean CADIA values 7.8 +/- 8.4 for the experimental group and -0.3 +/- 10.5 for the control group). These differences were statistically significant (p < 0.04). The digitized series of standardized radiographs were also evaluated for changes in bone height. The distance from the alveolar bone crest to reference points were measured in mm within the baseline: the 1, 2, 3 and 6 month radiographs.(ABSTRACT TRUNCATED AT 250 WORDS)

Macaca fascicularis as a model in which to assess the safety and efficacy of a vaccine for periodontitis

We have assessed Macaca fascicularis as a potential model in which to test the efficacy and safety of a vaccine for periodontitis. Twenty-eight animals were surveyed and 20 studied in more detail. Clinical periodontal status was assessed, the subgingival microflora analyzed especially for the presence and proportions of Porphyromonas gingivalis and titers and avidities of serum antibodies reactive with P. gingivalis measured. Probing depths ranged from 0.90 mm to 3.80 mm, Gingival Index scores from 0.00 to 4.00 and Plaque Index scores from 0.00 to 3.00. About 40% of sites bled on probing. The animals manifested a subgingival flora characteristic of the anaerobic gram-negative bacteria found in human periodontal pockets, including Actinobacillus actinomycetemcomitans, P. gingivalis, Bacteroides forsythus, Campylobacter rectus, Prevotella intermedia and Fusobacterium nucleatum. P. gingivalis was detected in 70 of 80 samples studied, ranging from 0.01% to 20% of the total flora. Serum antibody reactive with antigens of P. gingivalis was observed in all animals, with titers ranging from 1.0 enzyme-linked immunosorbent assay (ELISA) unit to 25 ELISA units and avidities from 0.10 M to 2.20 M. Antibody titer and maximum percentage of P. gingivalis were inversely correlated, indicating that a humoral immune response may be effective in reducing P. gingivalis overgrowth. M. fascicularis appears to be an excellent model for use in vaccine development.

The effect of systemically-administered flurbiprofen as an adjunct to toothbrushing on the resolution of experimental gingivitis

Non-steroidal anti-inflammatory drugs (NSAIDs) have been widely researched in an attempt to control periodontal diseases. This double-blind parallel group study investigated the effect of a systemic flurbiprofen preparation (100 mg daily), when combined with toothbrushing on the resolution of experimental gingivitis in human volunteers. 47 volunteers abstained from tooth cleaning for 21 days. On day 21, 23 subjects were prescribed 100 mg of flurbiprofen daily whereas 24 subjects were prescribed placebo. In both groups, toothbrushing was re-introduced and all subjects used the Bass technique for 2 min each day. Both treatment regimens were continued for 7 days. Plaque indices, gingival indices and gingival crevicular fluid flow were assessed at baseline (day 0) and on days 21 and 27. There were no significant differences at p = 0.05 between the groups for plaque indices or gingival crevicular fluid flow. The flurbiprofen group, however, demonstrated greater resolution of gingival inflammation by day 27 when compared to the placebo controls (p = 0.04). The plasma levels of flurbiprofen in the test group showed mean concentrations of flurbiprofen of 4.7 (+/- 2.1) micrograms/ml at 1 h after dosing. After 6 h, this had fallen to 4.4 (+/- 1.6) micrograms/ml. It is concluded that these serum concentrations of flurbiprofen are sufficient to produce significant anti-inflammatory effects in the gingival tissues.

Immunization against Porphyromonas gingivalis inhibits progression of experimental periodontitis in nonhuman primates

Periodontitis is a common infectious disease in which the attachment tissues of the teeth and their alveolar bone housing are destroyed, resulting in tooth loss. The gram-negative anaerobic microorganism Porphyromonas gingivalis has been closely linked to severe forms of the disease. We show for the first time that immunization of the primate Macaca fascicularis with killed P. gingivalis in Syntex Adjuvant Formulation-M inhibits progression of periodontal tissue destruction.

Improvement of gingival and alveolar bone status in periodontitis-affected hamsters treated with 15-methyl prostaglandin E1

Exogenous PGE1 at pharmacological doses suppresses acute and chronic inflammation manifestations. As periodontitis possesses features of both acute and chronic inflammation, attenuation of periodontal destruction in hamsters was attempted by using 15-M-PGE1, a stable PGE1 analog. The agent was tested at 2 different doses (100 and 150 micrograms/kg/d) and its effects were matched against disease-free and periodontitis-affected animals. No effect was found with the 100 micrograms regimen. In contrast, in the 150 micrograms group, in the gingiva around the first right mandibular molar the pocket epithelium and infiltrated connective tissue (ICT) areas, the mean vascular lumen, the number of PMNLs adherent to blood vessels and infiltrating the ICT were significantly reduced. The number of osteoclasts was markedly diminished as well, but their intrinsic activity was enhanced. Bone formation was totally inhibited in this treatment group. These results indicated that 15-M-PGE1 effectively improved gingival inflammation mostly by reducing edema and PMNL recruitment and controlled alveolar bone destruction by reducing the osteoclast recruitment. From a therapeutic point of view the complete inhibition of formation seems to contraindicate its use.

Histomorphometrical analysis of the effects of the bisphosphonate alendronate on bone loss caused by experimental periodontitis in monkeys

This study tested the efficacy of alendronate, a bisphosphate, in reducing alveolar bone loss caused by experimental periodontitis in cynomolgus monkeys. Periodontitis was initiated in adult monkeys by ligating mandibular molar teeth at the cementoenamel junction (CEJ) and subsequently inoculating the ligature with Porphyromonas (Bacteroides) gingivalis. Contralateral, homologous non-ligated teeth served as controls. Animals received, intravenously, either saline (placebo) or alendronate at 0.05 or 0.25 mg/kg every 2 weeks for 16 weeks. After the animals were sacrificed, coronal sections through mandibular molars were subjected to histomorphometrical analysis. No overt side-effects were observed in any of the animals participating in this study. In placebo-treated animals, ligation and inoculation resulted in significant bone loss both at the CEJ and at the furcation. Alendronate at 0.05 mg/kg significantly reduced bone loss associated with the experimental periodontitis at both sites. In contrast, the dose of 0.25 mg/kg was ineffective in attenuating alveolar bone loss in the furcation area and only slightly effective in preventing it at the CEJ area. The results of the histomorphometric analysis correlate closely with those of the radiographic analysis of the same experiment. These data indicate that alendronate could reduce the loss of alveolar support associated with periodontitis and suggest that bisphosphonates, by virtue of their significant inhibitory action on osteoclasts, may become a treatment modality in the battle against alveolar bone destruction during periodontal disease.

Effects of nonsteroidal antiinflammatory drugs on bone loss in chronic inflammatory disease

Several controlled clinical trials have indicated that nonsteroidal antiinflammatory drugs may slow alveolar bone loss in periodontitis. Demonstration of this efficacy is dependent on the development of accurate, sensitive, and specific quantitative methods for the assessment of bony change, such as digital subtraction radiography. Further studies of such methodologies are required to more fully investigate the effect of nonsteroidal antiinflammatory drugs in rheumatoid arthritis.

The effect of systemic ibuprofen on gingival inflammation in humans

This clinical trial investigated the influence of short-term ibuprofen therapy on the early phase of the treatment of adult chronic periodontitis. The subjects were 17 patients in good general health referred for specialist periodontal treatment, having moderate chronic adult periodontitis. A series of assessments were made every 2 weeks over an 8-week period, including evaluations of oral hygiene, gingival inflammation and probing pocket depths. All participants received oral hygiene instruction, and following baseline examinations, had half the dentition, chosen at random, treated by scaling and root planing. The patients were randomly distributed into 2 groups, a test group receiving a 14-day course of 800 mg ibuprofen daily, in 4 divided doses, and a control group who did not receive any drug regime. At the 2-week assessment following the drug regime, significantly greater reduction in gingival bleeding, colour and pocketing was detected in the test compared with the control group. The beneficial effects were less evident thereafter. Although clinical application of the regime used in this study would not be justified by these results, further research into anti-inflammatory agents as an adjunct in the treatment of periodontal diseases could be considered, in the light of the beneficial effect on gingivitis in the early phase of periodontal treatment reported.

Efficacy of meclofenamate sodium (Meclomen) in the treatment of rapidly progressive periodontitis

This 6-month, double-blind, controlled clinical trial determined the efficacy of the non-steroidal anti-inflammatory drug, meclofenamate sodium (Meclomen), as an adjunct to scaling and root planing in the treatment of rapidly progressive periodontitis (RPP). 22 subjects (7 male, 15 female) aged 36.5 +/- 7.88 years with RPP and disease-active sites as determined by pretreatment bone scan had standardized radiographs at baseline and 6 months, and clinical measurements at baseline, 3 and 6 months. Following full-mouth scaling and root planing, subjects were randomly assigned to either a placebo, 50 or 100 mg meclofenamate sodium bid group. Bone change over the 6-month period as assessed by subtraction radiography was the primary efficacy determinant. Specialized software was used to isolate the lesion from the subtraction image and to measure bone change along the root surface. ANOVA using the subject as the unit of analysis revealed a significant dose response (p < 0.001) with the placebo group having a mean bone loss of 0.42 +/- 0.06 mm and the low and high dose groups having mean bone gains of 0.07 +/- 0.05 and 0.20 +/- 0.07 mm, respectively. These findings indicate that meclofenamate sodium may be a useful adjunct in the treatment of rapidly progressive periodontitis.

Blocking periodontal disease progression with anti-inflammatory agents

Recent advances in the identification of specific immuno-inflammatory pathways of periodontal disease have encouraged investigators to attempt to modulate some of these host responses in an attempt to slow the periodontal disease process. Some of the best known mediators of these immuno-inflammatory pathways are prostaglandins. The action of prostaglandins can be inhibited through the use of non-steroidal anti-inflammatory drugs (NSAIDs). This review examines research over the last two decades during which the effect of several NSAIDs on the progression of gingival inflammation and alveolar bone loss was explored.

Macaca nemestrina: a non-human primate model for studies of periodontal disease

The non-human primate Macaca nemestrina was evaluated for use as a potential model in periodontal research by study of 16 animals. Using one incisor, premolar, and molar per quadrant, we measured supragingival plaque, severity of gingival inflammation, and pocket depth, and analyzed the subgingival flora. Serum IgG titers and avidities to antigens of Porphyromonas gingivalis (Pg) and Actinobacillus actinomycetemcomitans (Aa) were also assessed. Ten animals were between 13 and 24 years old, and six were between 4 and 5 years old. While mean gingival inflammation scores were significantly higher for older than for younger animals (2.2 vs 1.8, p < 0.05), mean plaque index scores and mean probing depths did not differ significantly. The animals harbored a subgingival microflora considered to be pathogenic for humans including Aa, Pg, Bacteroides forsythus, Prevotella intermedia I and II, Campylobacter recta and Fusobacterium nucleatum. Aa, however, was found only in the younger animals. All of the animals had serum IgG antibodies reactive with antigens of Pg and Aa, and titers for Pg but not for Aa were significantly higher in the older relative to the younger animals (t test p < 0.02). In contrast, antibody avidity did not significantly differ between the two groups. A combined clinical assessment index based on maximum probing depth, gingival index score, and tooth loss was used to assess the overall disease severity. Titers were positively associated with disease severity (Spearman's rank correlation 0.57, p = 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

The use of topical flurbiprofen as an adjunct to non-surgical management of periodontal disease

Non-steroidal anti-inflammatory drugs (NSAIDs) have been used as systemic and topical preparations to control chronic periodontal disease in both animal and clinical human trials. Equivocal findings have failed to confirm whether any one NSAID is particularly efficacious, although flurbiprofen appears to be one of the most promising. 49 patients were allocated at baseline to test (25) and control (24) groups in a 12-month, controlled clinical trial. The groups were of similar age and sex distributions. During the first 3 months, both groups were given oral hygiene instruction and received scaling and root planning. The test patients were prescribed a 1% w/w flurbiprofen toothpaste to use 2 x daily for the entire 12 months. Control subjects were prescribed a placebo dentifrice. Plaque scores, bleeding scores, crevicular fluid flow, probing pocket depths and attachment levels were assessed at baseline and at 3, 6, 9 and 12 months. Radiographs were taken at baseline and 12 months using a modified intraoral, repositionable film holder. Both the flurbiprofen and placebo showed significant improvements in the clinical parameters over 12 months and there were no significant differences between the groups. Flurbiprofen-treated patients however, demonstrated a significantly greater proportion of sites (8.0%) with bone gain when compared to the placebo group (3.3%). There were no significant differences between the groups in the number of sites showing bone loss or no change. It is concluded that the 1% w/w flurbiprofen toothpaste exerts a small, yet significant effect on bone metabolism in the absence of any apparent effects on clinical parameters.