Impact of cannabis sativa (marijuana) smoke on alveolar bone loss: a histometric study in rats.

BACKGROUND: Cannabis sativa (marijuana) can interfere with bone physiopathology because of its effect on osteoblast and osteoclast activity. However, its impact on periodontal tissues is still controversial. The present study evaluates whether marijuana smoke affects bone loss (BL) on ligature-induced periodontitis in rats. METHODS: Thirty male Wistar rats were used in the study. A ligature was placed around one of the mandible first molars (ligated teeth) of each animal, and they were then randomly assigned to one of two groups: control (n = 15) or marijuana smoke inhalation ([MSI] for 8 minutes per day; n = 15). Urine samples were obtained to detect the presence of tetrahydrocannabinol. After 30 days, the animals were sacrificed and decalcified sections of the furcation area were obtained and evaluated according to the following histometric parameters: bone area (BA), bone density (BD), and BL. RESULTS: Tetrahydrocannabinol was positive in urine samples only for the rats of the MSI group. Non-significant differences were observed for unligated teeth from both groups regarding BL, BA, and BD (P >0.05). However, intragroup analysis showed that all ligated teeth presented BL and a lower BA and BD compared to unligated teeth (P <0.05). The intergroup evaluation of the ligated teeth showed that the MSI group presented higher BL and lower BD (P <0.05) compared to ligated teeth from the control group. CONCLUSION: Considering the limitations of this animal study, cannabis smoke may impact alveolar bone by increasing BL resulting from ligature-induced periodontitis.

Effects of hyperbaric oxygen therapy on the treatment of severe cases of periodontitis.

OBJECTIVES: To evaluate the effect of hyperbaric oxygen therapy (HBO2) as an adjunct to scaling and root planing (SRP) in the treatment of severe cases of chronic periodontitis. MATERIALS AND METHODS: In 20 patients diagnosed with severe generalized chronic periodontitis (pockets>7mm) with bleeding on probing, SRP was rendered in all pockets. Additionally, five consecutive hyperbaric sessions were administered in 10 patients after random allocation (SRP + HBO2). Clinical parameters were assessed at baseline up to six months: plaque index, bleeding on probing, probing depth, clinical attachment level and benzoyl-DL-arginine-naphthylamide (BANA) test. RESULTS: SRP + HBO2 resulted in greater probing reduction and attachment gain than SRP alone three months after treatment (p<0.001). The BANA test was negative after one week only for sites in the SRP + HBO2 group (p<0.05). However, SRP + HBO2 failed to show a significant difference from SRP group after 3 months, where all BANA sites became negative (p>0.05). CONCLUSION: Our data suggest that hyperbaric oxygen therapy had a short-term beneficial effect on pocket reduction and bacterial elimination, and may be considered a potential adjunct therapeutic option to improve the clinical outcomes of scaling in severe cases of chronic periodontitis.

Chronic stress may modulate periodontal disease: a study in rats.

BACKGROUND: The present study aimed to evaluate whether chronic stress (CS) affects ligature-induced periodontal disease and to investigate the impact of CS on the mRNA levels of interleukin (IL)-1beta, -1 receptor antagonist, -6, and -10, interferon-gamma (IFN-gamma), receptor activator of nuclear factor-kappa B ligand (RANKL), and osteoprotegerin in the gingival tissues of rats. METHODS: Sixty male Wistar rats were assigned randomly to three groups: G1 (control; non-ligated sites), G2 (periodontal disease), and G3 (periodontal disease associated with restraint stress for 12 hours/day for the entire study). After 30 days, all animals were sacrificed by decapitation. Blood samples were taken, and the concentrations of corticosterone and catecholamines were measured as biomarkers of CS. Marginal tissues around ligated and non-ligated teeth were harvested, and gene expression was assessed by quantitative polymerase chain reaction. Moreover, the area of bone loss (ABL) was determined histometrically. RESULTS: Data analysis showed that CS increased serum levels of stress biomarkers (P <0.05), ligature placement resulted in a significant ABL compared to non-ligated sites, CS significantly increased the amount of ABL in inflamed sites (P <0.001), and CS significantly increased mRNA levels of proinflammatory (IL-1beta and -6 and IFN-gamma) and anti-inflammatory (IL-10) cytokines and proresorptive factor (RANKL) in ligated sites (P <0.05). CONCLUSION: CS significantly increased bone loss resulting from ligature-induced periodontitis by a local increase in proinflammatory and proresorptive factors.

A systematic review of stress and psychological factors as possible risk factors for periodontal disease.

BACKGROUND: Clinical observations and epidemiologic studies suggest that some negative life events and psychological factors may contribute to an increased susceptibility to periodontal disease. The aim of the present study was to systematically review the evidence from case-control studies, cross-sectional studies, and prospective clinical trials reporting on the influence of stress and psychological factors on periodontal disease. The focused question addressed in this systematic review was whether the scientific evidence is enough to consider stress and psychological factors as risk factors for periodontal disease. METHODS: A literature search was conducted using two databases (MEDLINE and the Cochrane Oral Health Group specialist trials register) in addition to searching reference lists of original and review articles. The search strategy used was the combination of the terms: "stress," "periodontal disease," and "psychosocial disorders." Studies were selected if they were published in dental journals between January 1, 1990 and April 1, 2006; only human studies and studies with adults and middle-aged subjects were included. Suitable variables included control for the potential effect of confounding factors, adequate criteria to define periodontal disease, adequate criteria for establishing stress, and methodologic quality. Only English-language articles were considered, and unpublished data were not sought. Two reviewers independently extracted information regarding quality and study characteristics in duplicate. The studies were assessed regarding their methodologic characteristics, statistical analysis, characteristics of the periodontal outcome measures, and psychological measurements. RESULTS: Of the 58 articles identified in the search, 10 were excluded because they were reviews and 34 did not comply with the selection criteria. Fourteen articles (seven case-control studies, six cross-sectional studies, and one prospective clinical trial) were included in the analysis; their quality and main study characteristics were assessed according to the criteria preestablished in the protocol of the study. With regard to the results of the studies, 57.1% found a positive outcome between psychosocial factors/stress and periodontal disease, 28.5% observed a positive outcome for some characteristics and a negative outcome for others, and 14.2% found a negative outcome. CONCLUSIONS: Within the limitations of this systematic review, the majority of studies showed a positive relationship between stress/psychological factors and periodontal disease. However, in the future, well-designed and more representative studies should be considered to confirm these factors as a risk for periodontal disease.

Coronally positioned flap with or without acellular dermal matrix graft in gingival recessions: a histometric study.

PURPOSE: To evaluate, histometrically, the healing of gingival recession treated by coronally positioned flaps (CPF) with or without acellular dermal matrix (ADM) as a subepithelial graft. METHODS: Gingival recessions were created on the upper cuspids of six dogs and were randomly assigned to: CPF+ADM (ADM group) or CPF alone (CPF group). After 4 months, the dogs were sacrificed, and the histometric measurements were performed. RESULTS: The epithelial length was 2.28 + 0.92 mm and 2.10 + 0.46 mm for the ADM and CPF groups, respectively (P=0.74). The connective tissue adaptation was 0.05 + 0.08 mm for the ADM group and 0.06 + 0.08 mm for the CPF group (P=0.36). The new cementum was 2.35 + 1.55 mm and 2.90 + 0.96 mm in the ADM and CPF groups, respectively (P=0.53). The new bone was 0.60 + 1.36 mm for the ADM group and 0.35 + 0.82 mm for the CPF group (P=0.53). The gingival recession was -0.88 + 1.33 mm in the ADM group and -0.21 + 0.22 mm in the CPF group (P=0.21). The gingival thickness was 1.63 + 0.28 mm in the ADM group and 1.16 + 0.20 mm in the CPF group (P=0.002).

Enamel matrix derivative and guided tissue regeneration in the treatment of dehiscence-type defects: a histomorphometric study in dogs.

BACKGROUND: The goal of this investigation was to histologically and histometrically evaluate the healing process of dehiscence-type defects treated by enamel matrix derivative (EMD) and/or guided tissue regeneration (GTR). METHODS: Seven mongrel dogs were used. Buccal osseous dehiscences were surgically created on the mesial roots of the mandibular third and fourth premolars. The defects were exposed to plaque accumulation for 3 months. After this period, the defects were randomly assigned to one of the treatments: open flap debridement (OFD), enamel matrix derivative (EMD), GTR with bioabsorbable membrane (GTR), and the combination of both procedures (EMD + GTR). After 4 months of healing, the dogs were sacrificed and the blocks were processed. The histometric parameters evaluated included gingival recession, epithelial length, connective tissue adaptation, new cementum, and new bone. RESULTS: A superior length of new cementum was observed in the sites treated by EMD (3.7 mm) and EMD + GTR (3.8 mm) in comparison with OFD (2.4 mm) (P < 0.05). No statistically significant differences were found in the remaining histometric parameters. CONCLUSIONS: Within the limits of this study, it can be concluded that EMD alone or in combination with GTR barriers may effectively promote new cementum formation. The combination of both therapies may not provide additional benefits.

Nicotine effects on alveolar bone changes induced by occlusal trauma: a histometric study in rats.

BACKGROUND: The aim of the present study was to verify nicotine effects on alveolar bone changes induced by occlusal trauma during a periodontitis experimental model in rats. METHODS: Thirty adult male rats were used. The animals were randomly assigned to one of three groups receiving daily intraperitoneal injections: A, nicotine solution (0.44 mg/ml) and occlusal overload; B, saline solution and occlusal overload; or C, saline solution. Rats from groups A and B underwent bilateral amputation of the second and third molar cusps to simulate an occlusal overload. The first molars were then randomly assigned to receive a cotton ligature in the sulcular area, while the contralateral tooth was left unligated. The animals were sacrificed 30 days later. The resected mandibles were processed, and histomorphometric measurements were performed in the alveolar bone adjacent to the furcation area of the first molars. RESULTS: Nicotine enhanced the bone loss induced by occlusal trauma (P<0.001) on the ligated teeth of group A (12.27 +/- 4.4 mm2), when compared to groups B (8.43 +/- 3.51 mm2) and C (4.43 +/- 2.17 mm2). Alveolar bone loss (P<0.01) was also observed in the contralateral teeth of groups A (nicotine + trauma) and B (saline + trauma), when compared to group C (saline only). CONCLUSION: Within the limits of the study, it is concluded that nicotine may influence the alveolar bone changes induced by occlusal trauma by enhancing bone loss.

Locally delivered doxycycline as an adjunctive therapy to scaling and root planing in the treatment of smokers: a clinical study.

BACKGROUND: The aim of this clinical study was to evaluate the association of locally delivered doxycycline (10%) with scaling and root planing in the periodontal treatment of smokers. METHODS: Forty-three patients with chronic periodontitis and a minimum of four pockets (> or = 5 mm) on anterior teeth that bled on probing were selected. Patients were randomly assigned to scaling and root planing (SRP) or scaling and root planing followed by local application of doxycycline (SRP-D). Plaque, bleeding on probing, gingival recession, relative attachment level (RAL), and probing depth (PD) were recorded at baseline, 45 days, and 3 and 6 months. Differences between baseline and each period were considered for analysis. RESULTS: At 6 months, no difference was found between groups regarding plaque, bleeding reduction, gingival recession or PD (P > 0.05). However, RAL gain was greater for SRP-D (1.63 +/- 0.93 mm) than for SRP (1.04 +/- 0.71 mm) (P = 0.025). In addition, deep pockets (> or = 7 mm) showed a significant reduction (3.78 +/- 1.41 versus 2.60 +/- 1.28 mm, P = 0.039) and RAL gain (2.54 +/- 1.27 mm versus 1.29 +/- 0.95 mm, P = 0.01) when doxycycline was applied. The proportion of sites showing RAL gain of 1 to 2 mm was 36.8% versus 21.7% for SRP-D and SRP, respectively (P = 0.01). CONCLUSION: The use of locally delivered doxycycline may constitute an important adjunct for the treatment of severe periodontal disease in smokers.

Stress may enhance nicotine effects on periodontal tissues. An in vivo study in rats.

OBJECTIVES AND BACKGROUND: Diabetes mellitus and smoking have been described as important risk factors that may affect the initiation and progression of periodontitis. Recent studies have pointed to potentially periodontal risk indicators, which include stress. The present study investigated the effects of stress associated with nicotine administration on periodontal breakdown resulting from ligature-induced periodontitis in rats. METHODS: Twenty adult male Wistar rats were used. After anesthesia, both mandibular first molars received a cotton ligature in the dento-gingival area. The animals were randomly assigned to one of the following experimental groups: A - saline solution, B - 0.73 mg of nicotine/kg/d (intraperitoneal), C - stress (immobilization - 2 h/d/40 d) associated with an intraperitoneal administration of saline solution, and D - stress (immobilization - 2 h/d/40 d) associated with an intraperitoneal injection of 0.73 mg of nicotine/kg/d. Forty days later, the animals were sacrificed and the specimens routinely processed for serial decalcified sections. RESULTS: Intergroup analysis (ANOVA) revealed a greater bone loss (P < 0.05) in the animals of group D compared with the animals from groups A, B and C. In addition, the data revealed a significant effect of nicotine (group B) compared with groups A and C (P < 0.05), and no difference between groups A and C (P > 0.05). CONCLUSION: Within the limits of the present study, although stress did not affect periodontitis by itself, it significantly enhanced the effects of nicotine on the periodontal tissues.

A influência do sexo e da idade na prevalência de bolsas periodontais / The influence of gender and age on the prevalence of periodontal pockets

Este trabalho teve como objetivo avaliar a influência dos fatores de risco na prevalência de bolsas periodontais em pacientes atendidos na clínica do terceiro e quarto anos da Faculdade de Odontologia de Piracicaba - Unicamp. Foram avaliados 100 pacientes através do levantamento dos dados contidos nas fichas clínico-anamnésicas, sendo consideradas bolsas de profundidade: 3 mm, 5 mm, 7 mm e 10mm, de acordo com o sistema diagnóstico WS (SALLUM; SALLUM, 1996). Os resultados foram comparados entre as profundidades de sondagem e as variáveis idade, sexo, bem como sua distribuiçäo por sextantes. Observou-se maior prevalência de bolsas periodontais no sexo masculino, bem como maior profundidade de sondagem em pacientes acima de 31 anos. A distribuiçäo de bolsas periodontais entre os sextantes foi homogênea