Enhanced collagenase activity in diabetic rat gingiva: in vitro and in vivo evidence

Morphological Study of the Articular Disc and Capillary of the Retrodiscal Tissue in a Type 2 Spontaneous Diabetes Mellitus Rat Model

The objective of this study was to evaluate morphological changes at the articular disc of the temporomandibular joint and capillary of the retrodiscal tissue in a rat model for type 2 spontaneous diabetes mellitus (DM) (i.e., Goto-Kakizaki [GK] rats) compared to normal Wistar rats. A total of 20 experimental rats were used in this study; the rats were categorized into the normal (n = 10 male 8-week-old Wistar rats) and DM (n = 10 male 8-week-old GK rats) groups. Hematoxylin-eosin stained specimens were obtained from 5 rats from each group. Image analyses of the hematoxylin-eosin stained specimens were conducted using light micrographs, which allowed comparisons of the thickness of the anterior, central, and posterior parts of the articular disc. Afterwards, the microvascular corrosion cast specimens were obtained from 5 rats from each group. The diameter of the capillary of the retrodiscal tissue was determined by analyzing scanning electron micrographs of the microvascular corrosion cast specimens. Student's t-test was used to test for statistical significant differences between the 2 groups. Differences were considered significant when p < 0.01. We found that the thickness of the anterior, central, and posterior parts of the articular disc, and the diameter of the capillary of the retrodiscal tissue was significantly lower in the DM vs. normal group. Therefore, we consider that DM-associated the hyperglycemia causes atrophy of the articular disc and microangiopathy of the capillary of the retrodiscal tissue in GK rats.

A novel chemically modified curcumin reduces inflammation-mediated connective tissue breakdown in a rat model of diabetes: periodontal and systemic effects

BACKGROUND AND OBJECTIVE

Periodontal disease is the most common chronic inflammatory disease known to mankind (and the major cause of tooth loss in the adult population) and has also been linked to various systemic diseases, particularly diabetes mellitus. Based on the literature linking periodontal disease with diabetes in a "bidirectional manner", the objectives of the current study were to determine: (i) the effect of a model of periodontitis, complicated by diabetes, on mechanisms of tissue breakdown including bone loss; and (ii) the response of the combination of this local and systemic phenotype to a novel pleiotropic matrix metalloproteinase inhibitor, chemically modified curcumin (CMC) 2.24.

MATERIAL AND METHODS

Diabetes was induced in adult male rats by intravenous injection of streptozotocin (nondiabetic rats served as controls), and Escherichia coli endotoxin (lipopolysaccharide) was repeatedly injected into the gingiva to induce periodontitis. CMC 2.24 was administered by oral gavage (30 mg/kg) daily; untreated diabetic rats received vehicle alone. After 3 wk of treatment, the rats were killed, and gingiva, jaws, tibia and skin were collected. The maxillary jaws and tibia were dissected and radiographed. The gingival tissues of each experimental group (n = 6 rats/group) were pooled, extracted, partially purified and, together with individual skin samples, analyzed for matrix metalloproteinase (MMP)-2 and MMP-9 by gelatin zymography; MMP-8 was analyzed in gingival and skin tissue extracts, and in serum, by western blotting. The levels of three bone-resorptive cytokines [interleukin (IL)-1β, IL-6 and tumor necrosis factor-α], were measured in gingival tissue extracts and serum by ELISA.

RESULTS

Systemic administration of CMC 2.24 to diabetic rats with endotoxin-induced periodontitis significantly inhibited alveolar bone loss and attenuated the severity of local and systemic inflammation. Moreover, this novel tri-ketonic phenylaminocarbonyl curcumin (CMC 2.24) appeared to reduce the pathologically excessive levels of inducible MMPs to near-normal levels, but appeared to have no significant effect on the constitutive MMPs required for physiologic connective tissue turnover. In addition to the beneficial effects on periodontal disease, induced both locally and systemically, CMC 2.24 also favorably affected extra-oral connective tissues, skin and skeletal bone.

CONCLUSION

This study supports our hypothesis that CMC 2.24 is a potential therapeutic pleiotropic MMP inhibitor, with both intracellular and extracellular effects, which reduces local and systemic inflammation and prevents hyperglycemia- and bacteria-induced connective tissue destruction.

A short-term evaluation of the relationship between plasma ascorbic acid levels and periodontal disease in systemically healthy and type 2 diabetes mellitus subjects

BACKGROUND

Deficient ascorbic acid levels (AALs) and Type 2 diabetes mellitus (T2DM) are associated with periodontal disease. This study evaluated the relationship between plasma AAL and periodontitis in systemically healthy and T2DM subjects, which to the best of our knowledge is being reported for the first time.

METHODS

One hundred twenty subjects were categorized into four groups of 30 each as group 1: without periodontal disease; group 2: chronic gingivitis; group 3: chronic periodontitis, and group 4: chronic periodontitis and freshly diagnosed T2DM. Plaque index (PlI), sulcus bleeding index (SBI), and probing pocket depths (PPDs) were evaluated. Venous blood was evaluated for plasma AAL spectrophotometrically. Randomized subjects were subgrouped within groups 2-4, to receive either scaling and root planing (SRP) with dietary supplementation (450 mg) of ascorbic acid (AA) for two weeks or only SRP. After two weeks, the clinical parameters were reassessed. Tukey's multiple post hoc procedures and paired t test were used with the level of statistical significance adjusted to p ≤ .05.

RESULTS

AAL plasma levels were significantly greater in group 1 than in group 2 (p = .0007) and in group 4 (p = .0003). A significant reduction in the SBI was seen in the subgroups that received dietary supplementation of vitamin C within group 2 (p = .0012) and group 4 (p = .036).

CONCLUSIONS

Plasma AAL is below the normal range in systemically healthy subjects with gingivitis and diabetics with periodontitis. Dietary AA supplementation with SRP improves the SBI in subjects with gingivitis and diabetics with periodontitis.

Green tea extract as a local drug therapy on periodontitis patients with diabetes mellitus: A randomized case-control study

Background:

The green tea extract is a naturally occurring product having beneficial effects that counteract with the pathobiological features of periodontitis and diabetes mellitus. Hence, the present study was aimed at incorporation of green tea extract into hydroxylpropyl methylcellulose and investigates its efficacy in chronic periodontitis patients associated with and without diabetes mellitus.

Materials and Methods:

For the in vitro study, formulation of green tea strips and placebo strips, and analysis of drug release pattern from the green tea strips at different time intervals were performed. For the in vivo study, 50 patients (20-65 years), including 25 systemically healthy patients with chronic periodontitis (group 1) and 25 diabetic patients with chronic periodontitis (group 2) were enrolled. In each patient, test and control sites were identified for the placement of green tea and placebo strips, respectively. Gingival Index (GI), Probing Pocket Depth (PPD), and Clinical Attachment Level (CAL) were examined at baseline, first, second, third, and fourth weeks. Microbiological analysis for Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans was performed at baseline and fourth week.

Results:

The in vitro study showed 10.67% green tea release at 30 min; thereafter, a slow release was noted till 120 min.

In vivo study:

Both groups showed significant reduction in GI scores at the test sites. Group 1 showed significant (P < 0.001) PPD reduction at different time intervals at the test sites. However, group 2 showed significant reduction from baseline (5.30 ± 0.70) to fourth week (3.5 ± 0.97). Statistically significant gain in CAL at the test sites was observed both in group 1 (1.33 mm) and group 2 (1.43 mm). The prevalence of P. gingivalis in group 1 test sites was significantly reduced from baseline (75%) to fourth week (25%).

Conclusions:

Local drug delivery using green tea extract could be used as an adjunct in the treatment of chronic periodontitis in diabetic and non-diabetic individuals.

Morphological study of the connective tissue papillae and the capillary loops on the lingual dorsum in the type 2 diabetes mellitus model rats

We performed a morphological study in type 2 diabetes mellitus (DM) model rats by focusing on the connective tissue papillae (CTPe) and capillary loops (CLs) of filiform papillae in the lingual dorsum in the type 2 DM model rats (GK rats). The normal group comprised nine 8-week-old male Wistar rats. The DM group comprised nine 8-week-old male GK rats. Image analysis of light microscopic specimens in CTPe was performed (height and cross-sectional area). Image analysis of scanning electron microscopic specimens (acrylic plastic injection method) in CLs was performed (number, thickness, height, interval between the tops of the two CLs, and crossing ratio between ascending and descending crura (CRC)). We compared these values between both groups (Student's t test). The former analysis revealed that the height and cross-sectional area of CTPe were smaller in the DM group than in the normal group. The latter analysis revealed that the thickness, height, and CRC of the CLs were smaller in the DM group than in the normal group. However, no significant differences were detected in the number and interval of CLs between both groups. Therefore, we concluded that DM caused regressive change in CTPe and CLs.

Commentary: prognosis revisited: a system for assigning periodontal prognosis

Prognosis is an integral part of the periodontal practice because it directly influences treatment planning. However, there is limited direct evidence in the literature regarding the assignment of periodontal prognosis. There are several important concepts to consider in developing a system of periodontal prognosis. Traditional systems are based on tooth loss and may have limited use for patient management. On the other hand, prognosis can be based on stability of the periodontal supporting apparatus, which is influenced by more evidence-based factors and may be more useful for patient management. Other important concepts include the timing of the projection (short and long term) and the consideration of individual teeth versus the overall dentition. Historically, several authors have formulated and investigated their own prognostication systems. Results were variable, but they generally showed that systems based on tooth loss were unpredictable over the long term. Therefore, the purpose of this report is to review relevant literature and propose a new periodontal prognostication system.

Alloxan-induced diabetes triggers the development of periodontal disease in rats

Background

Periodontal disease in diabetic patients presents higher severity and prevalence; and increased severity of ligature-induced periodontal disease has been verified in diabetic rats. However, in absence of aggressive stimuli such as ligatures, the influence of diabetes on rat periodontal tissues is incompletely explored. The aim of this study was to evaluate the establishment and progression of periodontal diseases in rats only with diabetes induction.

Methodology/Principal Findings

Diabetes was induced in Wistar rats (n = 25) by intravenous administration of alloxan (42 mg/kg) and were analyzed at 1, 3, 6, 9 and 12 months after diabetes induction. The hemimandibles were removed and submitted to radiographical and histopathological procedures. A significant reduction was observed in height of bone crest in diabetic animals at 3, 6, 9 and 12 months, which was associated with increased numbers of osteoclasts and inflammatory cells. The histopathological analyses of diabetic rats also showed a reduction in density of collagen fibers, fibroblasts and blood vessels. Severe caries were also detected in the diabetic group.

Conclusions/Significance

The results demonstrate that diabetes induction triggers, or even co-induces the onset of alterations which are typical of periodontal diseases even in the absence of aggressive factors such as ligatures. Therefore, diabetes induction renders a previously resistant host into a susceptible phenotype, and hence diabetes can be considered a very important risk factor to the development of periodontal disease.

Relationship Between Periodontitis and Diabetes: Lessons From Rodent Studies

BACKGROUND

A great amount of investigations have provided evidence that both type 1 and type 2 diabetes increase the risk and severity of periodontitis; several alterations in the diabetic periodontium are likely to be involved. Conversely, periodontitis has been shown to have an impact on diabetes, although less evidence is available on the underlying mechanisms. The association between periodontitis and diabetes has been discussed in several reviews over the past years; however, none has focused on the use and contribution of rodent models.

METHODS

This review describes the most commonly used rodent models of diabetes, periodontitis, and the association between the two diseases. Further, we summarize the influence of diabetes in the periodontium as well as the effect of periodontitis on diabetes status with special focus on evidence from experimental studies.

RESULTS

Rodent studies have confirmed human findings and further increased our knowledge on the alterations in the diabetic periodontium. On the other hand, few rodent investigations have explored the consequences of periodontitis for diabetes. Their results clearly indicate that periodontitis can become a health hazard not only for diabetes but also for prediabetes; the exact mechanisms are still to be unraveled.

CONCLUSIONS

Findings from rodent studies have been useful in increasing our understanding of periodontitis, diabetes, and their association and hold great promise for future investigations given the wide variety of possibilities for testing biologic hypotheses.

Diabetes and its effects on dental pulp

Uncontrolled or poorly controlled diabetes mellitus may be a risk factor for the development of oral complications. The objective of this investigation was to determine the effect of diabetes mellitus progression on inflammatory and structural components of dental pulp. Male Wistar rats were given a single injection of Streptozotocin (STZ), and induction of diabetes was confirmed 24 h later. Dental pulp tissue samples were taken from central incisors and molars of diabetic rats 30 and 90 days after the STZ treatment. Plasma glucose levels in diabetic rats 30 and 90 days after STZ treatment were significantly increased when compared to control rats (P < 0.001). Nitrite and kallikrein levels in dental pulp tissue were higher in diabetic rats 30 days after STZ treatment than in controls, while only nitrite were decreased 90 after of STZ treatment. Myeloperoxidase activity showed changes 30 and 90 days after STZ injection when compared to controls. The activity of alkaline phosphatase showed significant changes 30 and 90 days after STZ treatment. On the other hand the concentration of collagen was decreased in diabetic rats 30 and 90 days after STZ injection. These results suggest that diabetes is a critical factor that has profound effects upon oral tissues, resulting in expression of inflammatory mediators and modifications of structural components of dental pulp.

Update on diabetes mellitus and related oral diseases

Diabetes mellitus (DM) is a group of complex multisystem metabolic disorders characterized by a relative or absolute insufficiency of insulin secretion and/or concomitant resistance to the metabolic action of insulin on target tissues. The chronic hyperglycaemia of diabetes is associated with long-term systemic dysfunction. The present article summarizes current knowledge of DM and details the oral and dental implications of this common endocrine disorder.

Periodontal Health, Salivary Status, and Metabolic Control in Children with Type 1 Diabetes Mellitus

BACKGROUND

The aim of this study was to determine whether detectable periodontal destruction and alterations in the salivary status were present with duration of diabetes in children with type 1 insulin-dependent diabetes mellitus (type 1 DM) as compared to healthy controls.

METHODS

Sixteen newly diagnosed children with DM (group 1), 16 children with type 1 DM of long duration (group 2), and 16 healthy children (group 3) participated in the study. Periodontal health was assessed by plaque index, gingival index, bleeding on probing, and periodontal probing depths. The flow rate, pH, buffering capacity, and peroxidase activities of stimulated saliva were determined. The data were analyzed by Kruskall-Wallis, Student t test, and Pearson's correlation analysis.

RESULTS

The mean values for fasting blood glucose levels for the diabetic groups were significantly higher than for the controls. The mean values for salivary buffering capacities and salivary pH from the diabetic groups were significantly lower than for the controls. The plaque index values for the diabetic groups were significantly higher than for the controls. The mean gingival index value for group 1 was significantly lower than for group 2. The mean periodontal probing depths for group 1 were similar to those of the non-DM controls, but the mean periodontal probing depths for group 2 were significantly greater than for both the non-DM controls and group 1. Group 1 had significantly greater bleeding on probing scores than did the other groups (P < 0.05).

CONCLUSION

The glycemic status of the diabetic subjects affects the periodontal probing depths, salivary pH, buffering capacity, and peroxidase activity.

Dietary vitamin C and the risk for periodontal disease

BACKGROUND

Vitamin C has long been a candidate for modulating periodontal disease. Studies of scorbutic gingivitis and the effects of vitamin C on extracellular matrix and immunologic and inflammatory responses provide a rationale for hypothesizing that vitamin C is a risk factor for periodontal disease.

METHODS

We evaluated the role of dietary vitamin C as a contributing risk factor for periodontal disease utilizing the Third National Health and Nutrition Examination Survey (NHANES III) which is representative of the U.S. civilian, non-institutionalized population.

RESULTS

A sample of 12,419 adults (20 to 90+ years of age), with dental measurements and assessment of dietary information as well as demographic and medical histories were included in the studies. Dietary vitamin C was estimated by a 24-hour dietary record. Individuals with periodontal disease were arbitrarily defined as those who had mean clinical attachment levels of > or =1.5 mm. Using multiple logistic regression analysis, we found a relationship between reduced dietary vitamin C and increased risk for periodontal disease for the overall population (odds ratio [OR] = 1.19; 95% CI: 1.05 to 1.33). Current and former tobacco users who were taking less dietary vitamin C showed an increased risk of periodontal disease with OR of 1.28, 95% CI: 1.04 to 1.59 for former smokers, and an OR of 1.21, 95% CI: 1.02 to 1.43 for current tobacco users. There was a dose-response relationship between the levels of dietary vitamin C and periodontal disease with an OR of 1.30 for those taking 0 to 29 mg of vitamin C per day, to 1.16 for those taking 100 to 179 mg of vitamin C per day as compared to those taking 180 mg or more of vitamin C per day.

CONCLUSION

Dietary intake of vitamin C showed a weak, but statistically significant, relationship to periodontal disease in current and former smokers as measured by clinical attachment. Those taking the lowest levels of vitamin C, and who also smoke, are likely to show the greatest clinical effect on the periodontal tissues.

Diabetes and periodontal diseases. Committee on Research, Science and Therapy. American Academy of Periodontology

This position paper on diabetes mellitus was prepared by the Research, Science and Therapy Committee of The American Academy of Periodontology. It is intended to: 1) update members of the dental profession on the diagnosis and medical management of patients with diabetes mellitus; 2) summarize current knowledge on the relation between diabetes mellitus and periodontal diseases; 3) provide an overview of factors in diabetic patients relevant to understanding the pathogenesis of periodontal diseases in these subjects; 4) outline special considerations associated with treatment of periodontal diseases in diabetic patients; and 5) discuss possible approaches to the management of diabetic emergencies in the dental office.

Diabetes and periodontal diseases

This position paper on diabetes mellitus was prepared by the Research, Science and Therapy Committee of The American Academy of Periodontology. It is intended to: 1) update members of the dental profession on the diagnosis and medical management of patients with diabetes mellitus; 2) summarize current knowledge on the relation between diabetes mellitus and periodontal diseases; 3) provide an overview of factors in diabetic patients relevant to understanding the pathogenesis of periodontal diseases in these subjects; 4) outline special considerations associated with treatment of periodontal diseases in diabetic patients; and 5) discuss possible approaches to the management of diabetic emergencies in the dental office.

MMP-mediated events in diabetes

Both Type I and Type II diabetes mellitus (DM) have been associated with unusually aggressive periodontitis. Accordingly, rat models of both types of DM were used to study (i) mechanisms mediating this systemic/local interaction and (ii) new pharmacologic approaches involving a series of chemically modified tetracyclines (CMTs) that have lost their antimicrobial but retained their host-modulating (e.g., MMP-inhibitory) properties. In vitro experiments on tissues from Type I DM rats demonstrated that several of these CMTs were better matrix metalloproteinase (MMP) inhibitors than was antibacterial doxycycline (doxy), except for CMT-5, which, unlike the other MMP inhibitors, was found not to react with zinc. Data from in vivo studies on the same rat model generally supported the relative efficacy of these compounds: the CMTs and doxy were found to inhibit MMP activity, enzyme expression, and alveolar bone loss. To examine other long-term complications such as nephropathy and retinopathy, a Type II (ZDF) model of DM was studied. Treatment of these DM rats with CMT-8 produced a 37% (p < 0.05), 93% (p < 0.001), and 50% (p < 0.01) reduction in the incidence of cataract development, proteinuria, and tooth loss, respectively; whereas the doxy-treated ZDF rats showed little or no effect on these parameters. CMT treatment decreased mortality of the Type II ZDF diabetic animals, clearly indicating that CMTs, but not commercially available antibiotic tetracyclines (TCs), may have therapeutic applications for the long-term management of diabetes.

Tetracyclines inhibit connective tissue breakdown by multiple non-antimicrobial mechanisms

A seminal experiment involving a germ-free rat model of connective tissue breakdown (followed soon thereafter by a series of in vitro studies) identified an unexpected non-antimicrobial property of tetracyclines (TCs). This ability of TCs to inhibit matrix metalloproteinases (MMPs) such as collagenase was found to reflect multiple direct and indirect mechanisms of action, and to be therapeutically useful in a variety of dental (e.g., adult periodontitis) and medical (e.g., arthritis, osteoporosis, cancer) diseases. The site on the TC molecule responsible for its MMP-inhibitory activity was identified which led to the development of a series of chemically modified non-antimicrobial analogs, called CMTs, which also have therapeutic potential but do not appear to induce antibiotic side-effects. Longitudinal double-blind studies on humans with adult periodontitis have demonstrated that a sub-antimicrobial dose of doxycycline (previously reported to suppress collagenase activity in the periodontal pocket) is safe and effective and has recently been approved by the FDA as an adjunct to scaling and root planing.

Tetracyclines inhibit protein glycation in experimental diabetes

Glycation of proteins, which is accelerated in the diabetic state, has been implicated in many of the long-term complications of diabetes. This process can be inhibited by members of the tetracycline family of compounds. This novel finding is supported by studies conducted on drug (streptozotocin)induced Type I and genetic (ZDF/Gmi-fa/fa) Type II diabetic rats. These animals were orally gavaged daily with 5 mg of doxycycline and a variety of non-antimicrobial chemically modified tetracycline derivatives for time periods of 3 weeks to 11 months, while control untreated diabetic and nondiabetic animals were gavaged with vehicle alone (2% CMC). Blood and tissue samples were collected and analyzed for glucose and glycated proteins. None of the treatments had any effect on the severity of hyperglycemia or the intracellular glycation of hemoglobin of either Type I or II diabetic animals. However, the tetracycline analogues did affect the extracellular glycation of several proteins such as those found in the serum as well as skin collagen. In the Type II (ZDF) animals, initial mortality (3-5 months) was seen only in the doxycycline-treated animals, associated with infection by tetracycline-resistant micro-organisms, which was eventually surpassed by mortality rates in the untreated diabetics (6-9 months). CMT treatment not only decreased mortality but also increased longevity in the Type II diabetic animals, most likely by preventing the development of a number of long-term complications of uncontrolled diabetes, including glycation of proteins, that eventually lead to the demise of untreated diabetic animals.

Periodontal disease as a complication of diabetes mellitus

Based on our clinical observations that patients with insulin-dependent diabetes mellitus (IDDM) are subject to periodontal disease, we developed the hypothesis that hyper- or hypoglycemia might contribute to the pathogenesis of diabetic periodontitis. In this article, experimental facts that substantiate this hypothesis are presented on the basis of our studies and then discussed. Hyperglycemia progressively glycates body proteins, forming advanced glycation end products (AGE), which stimulate phagocytes to release inflammatory cytokines such as TNF-alpha and IL-6. In this context, to understand the effects of hyperglycemic episodes on periodontal health, 24 adolescent IDDM patients were examined for their periodontal status, and 3 of them were found to have periodontitis. Laboratory analyses on these 3 patients revealed that 2 had elevated serum TNF-alpha levels. These results may partly support the current hypothesis of a mechanism of diabetic complications in which abnormal cytokine levels induced by AGE could exacerbate inflammatory responses. In IDDM patients, the diabetes is often accompanied not only by hyperglycemic episodes but also by iatrogenic hypoglycemia. Periodontal ligament cells (PDL) cultured under hyperglycemic conditions were impaired in such biological functions as adhesion and motility, while cells cultured under hypoglycemic conditions (10 mg/dL) gradually dissociated from their anchor and underwent cell death. These phenomena correlated well with the expression profile of fibronectin receptor. Interestingly, these changes due to the different glucose levels were observed more intensively in PDL than in other fibroblastic cells, suggesting that the biological functions of PDL are easily led to impairment by variation or rapid fluctuation of glucose levels. These observations suggest that hyperglycemia could indirectly exacerbate inflammatory tissue destruction through the body's scavenger system against AGE, and that both hyper- and hypoglycemia might directly impair the biological functions of periodontal connective tissues through cell-matrix interactions.

A randomized clinical trial comparing the efficacy of mandibular implant-supported overdentures and conventional dentures in diabetic patients. Part I: Methodology and clinical outcomes

STATEMENT OF PROBLEM

Scientific evidence is lacking to support the general application of implant-supported mandibular overdentures.

PURPOSE

This randomized clinical trial was undertaken to compare the efficacy of conventional mandibular and implant-supported overdentures in diabetic edentulous patients with clinically acceptable metabolic control.

METHOD

A total of 102 diabetic patients, treated with or without insulin, were randomized to receive a new maxillary denture and either a conventional or an implant-supported removable mandibular overdenture. Treatment was completed for 89 patients, 37 with the conventional and 52 with implant-supported dentures. Detailed examinations, tests, and questionnaires were given before and at 6- and 24-months after treatment completion. Comparisons between the two treatment groups were made for treatment failures based on prespecifed criteria and the type and amount of maintenance care provided.

RESULTS

The insulin and noninsulin treated groups were collapsed because of the lack of significant differences at entry. The conventional denture and implant-supported overdenture groups were similar in terms of general demographics, medical status, quality of their original dentures and denture support, several functional measures, and patient satisfaction. Treatment was judged to be successful in 56.9% of patients with conventional dentures and 72.1% with overdentures. This difference in success rate was not statistically significant (p > 0.05). Patients with treatment failures in both groups required excessive maintenance care. Those with conventional dentures needed frequent denture base adjustments and relines, whereas those with overdentures required frequent clip replacements and repairs. Although significant improvements were seen with both treatment modalities, a higher percentage of patients with implant-supported overdentures than those with conventional dentures reported improvements in chewing comfort and moderate-to-complete overall satisfaction.

The relationship between clinical attachment loss and the duration of insulin-dependent diabetes mellitus (IDDM) in children and adolescents

The periodontal status of 77 diabetic children and adolescents, and 77 paired, systemically-healthy, sex- and age-matched control subjects, was clinical examined. Fasting blood glucose, fructosamine and glycosylated haemoglobin (HbA1) values were determined. The mean periodontal pocket depths, clinical attachment levels and the parameters to assess diabetes mellitus from the diabetic group were significantly higher than those of the controls. We found a positive correlation between the duration of diabetes and clinical attachment loss, but not with periodontal probing depth, plaque index and gingival index in the diabetic group. A positive correlation was also assessed between the present serum fructosamine and gingival index in the diabetic group, but not in controls.

Serum fructosamine correlates with gingival index in children with insulin-dependent diabetes mellitus (IDDM)

Fructosamine assay, which is used in diagnosing and monitoring diabetic patients, is compared with the hemoglobin and plasma glucose assays in children and adolescent insulin-dependent diabetes mellitus patients. We demonstrated that the gingival index scores were correlated with fructosamine values in insulin-dependent diabetes mellitus patients but not in non-diabetic controls. We also found that there was no correlation between gingivitis scores and fasting plasma glucose and HbA1c values. Periodontitis was found to be rare in diabetic children and adolescents.

Diabetes--a risk factor for periodontitis in adults?

With the increasing number of diabetics in an aging population and controversial research reports on the relationship of diabetes to periodontitis, clarification of diabetes as a risk factor for periodontitis would be helpful. This review notes variations in type, metabolic control, and duration of diabetes and highlights the results of studies that have considered these variations. Diabetics who maintained reasonably good metabolic control had not lost more teeth or experienced more periodontal attachment loss than non-diabetics, although they had more periodontal pockets. Poorly-controlled diabetics with extensive calculus on their teeth had more periodontitis and tooth loss than well-controlled diabetics or non-diabetics. Long-duration diabetics were also at greater risk for periodontitis. Mechanisms by which diabetes may contribute to periodontitis include vascular changes, neutrophil dysfunction, altered collagen synthesis, and genetic predisposition. Minimizing plaque and calculus in the oral cavity through careful self-care and regular professional care is important to reduce the risk of periodontitis in diabetics.

Fructosamine as a possible monitoring parameter in non-insulin dependent diabetes mellitus patients with periodontal disease

Fructosamine assay is a new test used in the diagnosis and monitoring of diabetic patients. This assay may be of interest to the periodontist for, while the traditional plasma glucose value would give a general view and information about diabetic control at a certain point, the fructosamine concentration gives an indication of the plasma glucose level over a considerable period of time, such as 1 to 3 weeks. We investigated whether there was any relation between the diseased state of the periodontal tissues and plasma fructosamine and the plasma glucose values in non-insulin dependent diabetes mellitus (NIDDM) patients. We found that fructosamine correlated with the degree of gingival bleeding, however serum glucose levels had little or no correlation.

Rapid periodontal destruction in adult humans with poorly controlled diabetes. A report of 2 cases

Out of a pool of 12 middle-aged or elderly diabetic patients demonstrating rapid periodontal break-down, the 2 oldest cases with follow-up periods of 19 and 16 years are described. The common feature of all 12 patients was that they were either unaware of or unable to control their diabetic condition at the time of the active stage of their periodontal disease. The bone loss progressed in spite of specialist periodontal care and the patients again responded to treatment only after their elevated blood glucose levels had been brought back to normal. Thus, the rapid periodontal breakdown was not found to be associated with the diabetic condition per se, but rather with the hyperglycemia. This clinical follow-up study does not answer the question of whether rapid periodontal destruction occurs in all patients with poorly controlled diabetes. Neither do the observations imply that rapid bone loss would be pathognomic of high blood glucose levels. However, the observations seem to suggest that there may be an inter-relationship between rapid periodontal breakdown and elevated blood glucose levels. Therefore, any sudden change towards an increased progression rate of periodontal breakdown at adult age, as observed from periodic radiographs with intervals of only a few years, should be followed up with a medical examination in order to outrule or verify the possibility of a high blood glucose level.

Relation of diabetes control to periodontal pocketing and alveolar bone level

The periodontal health status of 50 diabetic and 53 control subjects was examined. The diabetic group was further divided into three subgroups according to the control of diabetes. There were no significant differences between the whole diabetic group and the control group as regards the frequency of pockets and alveolar bone level. A comparison between the controls and the diabetic subgroups revealed that the well-controlled diabetic patients had better periodontal health than the controls. Within the diabetic group, the prevalence of pockets declined as the control of diabetes improved; the decrease in the number of pockets on bleeding surfaces and on surfaces containing subgingival calculus was statistically significant. Better periodontal health seems to be connected with good control of diabetes, indicating better resistance of periodontal connective tissue and alveolar bone.

Levels of salivary lysozyme, lactoperoxidase, and lactoferrin in diabetic hamsters

In an attempt to clarify the mechanism(s) of increased susceptibility to oral infection in diabetics, we examined the levels of salivary antibacterial factors, including lysozyme, lactoperoxidase, and lactoferrin, in diabetic hamsters whose condition was induced with streptozotocin. Saliva was collected from these hamsters periodically for 19 weeks after the administration of streptozotocin. Diabetes persisted with significant hyperglycemia throughout the experiment after a single injection of streptozotocin. There was no significant difference between groups in the amount of saliva secreted. In diabetic hamsters, lysozyme activity decreased by 56% and lactoperoxidase activity decreased by 53% compared with the control hamsters 19 weeks after the administration of streptozotocin. There was no significant difference between groups in the amount of salivary lactoferrin. However, the ratio of lactoferrin to total protein increased to approximately double the amount of that of the control hamsters. Insulin treatment had a significant effect on lysozyme and lactoperoxidase activity, recovering 73 and 74% those of the controls, respectively, and the ratio of lactoferrin to total salivary protein reverted to normal values. Growth inhibition of Lactobacillus plantarum ATCC 8014 with whole saliva and amylase activity significantly decreased in diabetic hamsters. The position of each protein band of whole saliva on sodium dodecyl sulfate-polyacrylamide gel electrophoresis was almost the same for control and diabetic hamsters; however, there was some variability in band intensity.

Periodontal disease in juvenile and adult diabetic patients: a review of the literature

Epidemiologic studies have suggested that the severity of periodontitis is greater in juvenile and adult onset diabetes. In juvenile diabetic patients, the periodontal disease seems to be initiated around puberty and progresses by age. Reviewing the medical literature indicates a similar age of onset for known systemic complications resulting from diabetes. Angiopathy, abnormal collagen metabolism, abnormal PMN function, and altered sulcular microbial flora have been found to be closely associated with the severity of periodontitis in diabetic patients. The association between abnormal neutrophil function and severity of periodontal disease in diabetic patients provides an opportunity for examining the role of neutrophil in periodontal disease. Future investigation in the function of sulcular PMN may shed light on the complex mechanism of periodontal disease.

The effect of streptozotocin-induced diabetes on prolyl hydroxylase activity in rat gingiva

The diabetes resulted in marked decrease in prolyl hydroxylase (EC 1.14.11.2) activity in rat gingiva. Insulin treatment of diabetic rats returned the decreased enzyme activity to the level of normal controls. The results suggest that diabetes decreases the rate of collagen biosynthesis in gingival tissue by inhibiting the hydroxylation of peptidyl proline in collagen precursors.

In vivo crevicular leukocyte response to a chemotactic challenge: inhibition by experimental diabetes

Diabetes in rats inhibits the migration of neutrophils into the healing gingival crevice, an effect associated with impaired in vitro neutrophil chemotactic activity. We recently described the in vivo response of human and rat crevicular neutrophils to a chemotactic challenge and used this assay in the present study on streptozotocin-induced diabetic rats. Optimal concentrations of two chemotactic agents, casein (0.2 mul, 2 mg/ml) or N-formylmethionylleucylphenylalanine (0.2 mul, 10(-4) M), were placed into the gingival crevices of control and diabetic rats (time zero) after the resting neutrophil count was measured. After a 15-min delay, the neutrophil counts and gingival crevicular fluid flow were assessed every 5 min for another 0.5 h. The control rats (n = 14) showed an increase in neutrophil counts which reached maximum levels 30 min after the N-formylmethionylleucylphenylalanine challenge ("peak" neutrophil response) and decreased dramatically 5 min later. Diabetes of 4 days (n = 4), 14 days (n = 8), and 20 days (n = 5) duration reduced the peak neutrophil response 45, 66, and 71%, respectively. Casein produced the same response as N-formylmethionylleucylphenylalanine in control rats. Uncontrolled diabetes of 20 days duration reduced the peak neutrophil response to casein by 83%; diabetics administered insulin on a daily basis showed a reduction of only 34%. The pattern of change in gingival crevicular fluid flow in response to chemoattractants paralleled the neutrophil response. The chemotactic activity of peritoneal neutrophils was assessed in vitro with the agarose gel technique and was found to be correlated (r = 0.84; P < 0.01) with the in vivo chemotactic response in the same rats. If the same in vivo defect is observed in humans with diabetes (or with other systemic diseases associated with leukocyte dysfunction), this test could be useful diagnostically to rapidly assess neutrophil chemotaxis in lieu of in vitro assays and to identify patients who are unusually susceptible to aggressive periodontal disease.

The development of an altered gingival crevicular microflora in the alloxan-diabetic rat

The microflora of the rat gingival crevice were examined at various time intervals after inducing experimental diabetes. A variety of Gram-positive and Gram-negative cocci and short rods were isolated from the normal rat crevice. Within a week after alloxan administration, Leptotrichia buccalis was detected for the first time. Other features in the diabetic animals included an increased frequency of isolation of Proteus spp., Lactobacillus spp. and decrease of Escherichia coli. Occasionally, a decrease was also observed in Bacteroides spp. and Streptococcus spp. No difference was observed between diabetic and non-diabetic animals in the isolation of Selonomonas, Campylobacter, Bifidobacterium and Actinomyces. Plaque accumulation was markedly increased in the diabetic rats. It was concluded that the change in gingival microflora resulted from diabetes-induced alterations in the sulcular environment (such as increased substrate levels, e.g. glucose and urea, and decreased oxygen) and that the microbiological changes preceded the depending of the periodontal pocket.