Biochemical and histopathologic analysis of the effects of periodontitis on left ventricular heart tissues of rats.

BACKGROUND AND OBJECTIVE: Current epidemiological works have suggested that chronic infections, such as periodontitis, are associated with an increased risk of cardiovascular diseases, including hypertrophy and heart failure. However, mechanisms behind the association are not known. The aim of this study was to evaluate the effects of periodontitis on the serum lipid levels, inflammatory marker levels and left ventricular heart muscle tissues of rats. MATERIAL AND METHODS: Eighteen male Sprague-Dawley rats were randomly divided into two groups: control (without ligature) and experimental periodontitis (EP; ligatured). Periodontitis was induced by placing ligatures (3.0 silk) at a submarginal position of the lower first molar teeth for 5 wk. Serum samples were collected for biochemical studies (C-reactive protein, interleukin-1ß, tumor necrosis factor-α and serum lipids), after which the rats were killed and heart tissue samples were obtained for histopathological and immunological studies (nuclear factor kappa B and ß-myosin heavy chain). RESULTS: Significant increases in C-reactive protein and interleukin-1ß levels and no statistically significant increase in tumor necrosis factor-α level were observed in the EP group compared to the control group. In addition, total cholesterol, low-density lipoprotein cholesterol and triglyceride levels were significantly higher in the EP group. Stereological and immunological findings showed that the number of nuclear factor kappa B-p65- and ß-myosin heavy chain-positive cardiomyocytes increased significantly in the left ventricular tissue samples of the rats with periodontitis. CONCLUSION: Early chronic phase effects of periodontitis on heart tissue are in the form of degenerative and hypotrophic changes. Prolonging the exposure to systemic inflammatory stress may increase the risk of occurrence of hypertrophic changes.

Melatonin prevents radiation-induced oxidative stress and periodontal tissue breakdown in irradiated rats with experimental periodontitis.

BACKGROUND AND OBJECTIVE: The aim of this study was to analyze the biochemical and histochemical effects of radiation therapy and protective melatonin administration on periodontal tissues in rats with experimental periodontitis. MATERIAL AND METHODS: Sixty male Sprague Dawley rats were divided into six groups, as follows: control; experimental periodontitis (Ped); radiotherapy administration (Rt); experimental periodontitis and exposure to irradiation (Ped-Rt); radiotherapy and protective melatonin administration (Rt-Mel); and periodontitis, radiation therapy and protective melatonin administration (Ped-Rt-Mel). The rats were killed at the end of the experimental procedure, and the oxidative stress level and periodontal destruction were compared among the groups. RESULTS: The oxidative stress index and the levels of 8-hydroxy-2'-deoxyguanosine, malondialdehyde and C-terminal telopeptide of type I collagen were found to be significantly higher in the Ped-Rt group compared with the Ped group (p < 0.05), and the levels were lower in the Ped-Rt-Mel group than in the Ped-Rt group (p < 0.05). Alveolar bone destruction and attachment level were also significantly lower in the Ped-Rt-Mel group than in the Ped-Rt group (p < 0.05). CONCLUSION: It was found that radiotherapy increased oxidative stress, the periodontal attachment level and alveolar bone loss, and protective melatonin administration significantly reduced the oxidative parameters and prevented periodontal damage in irradiated rats with experimental periodontitis. Further research is needed regarding the use of systemic melatonin administration before radiation therapy.

Influence of experimental periodontitis on cardiac oxidative stress in rats: a biochemical and histomorphometric study.

BACKGROUND AND OBJECTIVE: The role of oxidative stress in the process of cardiac remodeling, hypertrophy and heart failure is a current topic. The purpose of this experimental study was to investigate the influences of periodontitis on levels of cardiac oxidative stress. MATERIAL AND METHODS: Twenty rats were separated into two groups: control and experimental periodontitis (EP). Periodontitis was induced by placing a 3.0 silk suture in the cervix of the left and right mandibular first molar teeth for 5 wk. At the end of the experiment, the animals were killed and blood samples and mandibular and ventricular cardiac tissue samples were collected. Levels of alveolar bone loss were determined using measurements performed on histological slices and radiographies. Left ventricular tissue 8-hydroxy-2'-deoxyguanosine, malonylaldehyde, glutathione peroxidase, total oxidant status, total antioxidant status (TAS) levels and serum paraoxonase-1 activity were evaluated biochemically. RESULTS: Measurements performed on the histological slices and radiographies demonstrated that applying the ligature caused obvious alveolar bone loss. Oxidative damage markers (malonylaldehyde, 8-hydroxy-2'-deoxyguanosine, oxidative stress index: total oxidant status/TAS) were significantly higher, and antioxidant markers (glutathione peroxidase, TAS) were statistically insignificantly higher, in the hearts of rats with EP when compared to the controls. In addition, reduced serum paraoxonase-1 activity was also detected in the EP group. CONCLUSION: The pronounced increase in cardiac oxidative stress caused by periodontitis was due to an excessive increase in the production of reactive oxygen species, rather than due to decreased antioxidant capacity. The results indicate that periodontitis-related cardiac oxidative stress might be one of the mechanisms that contribute to the pathological process that leads to heart failure.

Role of nuclear factor kappa-B in phenytoin-induced gingival overgrowth.

OBJECTIVE: This study investigates the expression of transcription factor nuclear factor-kappa B (NF-κB) and its relation to various cellular mediators that act in the pathogenesis of phenytoin-induced gingival overgrowth. MATERIALS AND METHODS: Eighteen epileptic patients had phenytoin-induced gingival overgrowth (PHT-GO), 20 patients with plaque-induced gingivitis (Gingivitis), and 20 periodontally and systemically healthy individuals (Control) were included in this study. The expression of activated NF-κB subunits (p50 and p65), IL-1ß, TNF-α and TGFß-1 levels were examined in the gingival sections obtained from each participant. RESULTS: The results demonstrated a significantly higher expression of p65 in fibroblasts in PHT-GO group with respect to Gingivitis (P < 0.05) and control groups (P < 0.01). However, we found no statistically significant differences between PHT-GO and Gingivitis groups according to the immunohistochemical staining in macrophages (P > 0.05). Immune-reactive TGFß-1 levels in the gingival connective tissue cells were statistically higher in PHT-GO group with respect to Gingivitis group(P < 0.05). Statistically significant correlations were found between the HI and activated TGFß-1 and p65 levels in PHT-GO group. CONCLUSION: The results of this study showed that NF-κB is activated in PHT-related gingival overgrowth. This study may provide a basis for future research into specific NF-κB inhibition for preventing of the side effects of this drug.

Influence of tip wear of piezoelectric ultrasonic scalers on root surface roughness at different working parameters. A profilometric and atomic force microscopy study.

Roughness on tooth surfaces is reported to facilitate the reestablishment of microbial dental plaque. Hence, the main goal of dental scaling is to remove bacterial plaque and obtain smoother tooth surfaces. This study was aimed to assess the influence of tip wear of ultrasonic scaler inserts on root surface roughness at different working parameters. Twenty piezoelectric ultrasonic scaler inserts (10 worn/10 new) were selected to examine the erosion ratio (ER) on the scaler tips and to assess the influence of tip wear on root surface roughness. Erosion on the tip surfaces was evaluated under atomic force microscopy (AFM). Root samples were prepared and instrumented by new (Group I) and worn (Group II) inserts at different working parameters. Roughness change (Rc) on root surfaces after instrumentation was examined under profilometer and compared between and within the groups. Statistically significant differences were found between the mean ERs of new and worn tips (P < 0.01). The results of this study showed that tip angulation and instrument power strongly influenced the Rc values on instrumented samples (P < 0.05). It was also revealed that tip wear influenced the Rc values on root surfaces especially at 45° tip angulation (P < 0.05). Therefore, tip wear should also be considered as much as the other parameters to minimize the surface roughness during ultrasonic treatment.

Relationship between periodontal parameters and Behçet's disease and evaluation of different treatments for oral recurrent aphthous stomatitis.

BACKGROUND AND OBJECTIVE: The highest prevalence of Behçet's disease (BD) has been reported in Turkey, and therefore research of relations between BD and other disorders have become important in the Turkish population. Since oral aphthous ulcers impair tooth brushing, reducing complaints about aphthous ulcers will motivate the patient to maintain better oral hygiene performance and will thus reduce plaque accumulation and periodontal scores. The purpose of this controlled case study was to evaluate the relationship between the severity of periodontal scores and Behçet's disease, and to compare the treatment modalities with neodymium-doped yttrium aluminium garnet (Nd:YAG) laser and medication on the recurrent aphthous ulcers in BD patients by considering the degree of pre- and post-treatment pain, discomfort and functional complications. MATERIAL AND METHODS: The periodontal status of 28 BD patients was evaluated according to periodontal indices. The BD patients were also assessed for clinical severity score as described previously. Levels of pre- and post-treatment pain and functional complications were assessed at patient visits on days 1, 4 and 7. RESULTS: Periodontal indices, the number of oral ulcers and the daily frequency of tooth brushing were related to the severity scores of BD (p < 0.001). The results indicated that BD patients treated with the Nd:YAG laser had less post-treatment pain and fewer functional complications and reported immediate relief of pain and faster healing (p < 0.001). CONCLUSION: Our results suggest that periodontal status is worse in BD patients and is associated with disease severity; also, the Nd:YAG laser has better patient acceptance, shorter treatment time and lower rates of pain and post-treatment adverse events among BD patients with oral recurrent aphthous stomatitis.

The comparison of the effects of three types of piezoelectric ultrasonic tips and air polishing system on the filling materials: an in vitro study.

AIM: The aim of this study was to evaluate the effect of air polishing and different ultrasonic scaler inserts on dental fillings, such as amalgam, composite and porcelain. MATERIALS AND METHODS: This study was performed on amalgam, composite and porcelain samples. The surfaces of the samples were exposed to different type of piezoelectric ultrasonic scaler inserts and air-abrasive unit. The scaler inserts were Instrument A, Instrument PS and PI. The roughness of the surfaces of each sample were measured with a profilometer and observed by stereomicroscope. RESULTS: The stereomicroscopic images and profilometric values showed that Instrument A and PS resulted in rough surfaces, such as chips, nicks and scratches on the amalgam, composite and porcelain surfaces. The Instrument PI roughened the amalgam surface, but it did not roughen the porcelain or composite surfaces. The profilometric measurements (Ra) showed that the roughness of the surfaces depending on air polishing was less than the ultrasonically scaled surfaces. CONCLUSION: The wrong tip applications during dental scaling procedure cause roughness, such as scratches, nicks or chips, not only on the teeth surfaces but also on the filling materials. Thus, dental scaling procedure on the restorations should be performed carefully and the roughness sites on the restorations have to be re-polished after scaling to prevent plaque accumulation.

Sonic and ultrasonic scalers in periodontal treatment: a review.

Periodontal therapy aims at arresting periodontal infection and maintaining a healthy periodontium. The periodic mechanical removal of subgingival microbial biofilms is essential for controlling inflammatory periodontal disease. Mechanical periodontal therapy consists of scaling, root planing and gingival curettage. The sonic and ultrasonic scalers are valuable tools in the prevention of periodontal disease. The vibration of scaler tips is the main effect to remove the deposits from the dental surface, such as bacterial plaque, calculus and endotoxin. However, constant flushing activity of the lavage used to cool the tips and cavitational activity result in disruption of the weak and unattached subgingival plaque. The aim of the study was to review the safety, efficacy, role and deleterious side-effects of sonic and ultrasonic scalers in mechanical periodontal therapy.