Experimental and clinical studies on regenerative periodontal therapy.

The recognition of a periodontal therapy as a regenerative procedure requires the demonstration of new cementum, periodontal ligament, and bone coronal to the base of the defect. A diversity of regenerative strategies has been evaluated, including root surface conditioning, bone grafts and bone substitute materials, guided tissue regeneration, enamel matrix proteins, growth/differentiation factors, combined therapies and, more recently, tissue-engineering approaches. The aim of this chapter of Periodontology 2000 is to review the research carried out in Latin America in the field of periodontal regeneration, focusing mainly on studies using preclinical models (animal models) and randomized controlled clinical trials. This review may help clinicians and researchers to evaluate the current status of the therapies available and to discuss the challenges that must be faced in order to achieve predictable periodontal regeneration in clinical practice.

Microbial diversity similarities in periodontal pockets and atheromatous plaques of cardiovascular disease patients.

BACKGROUND AND OBJECTIVE: The immune and infectious alterations occurring in periodontitis have been shown to alter the development and severity of cardiovascular disease. One of these relationships is the translocation of oral bacteria to atheroma plaques, thereby promoting plaque development. Thus, the aim of this study was to assess, by 16s cloning and sequencing, the microbial diversity of the subgingival environment and atheroma plaques of patients concomitantly suffering from periodontitis and obstructive coronary artery atherosclerosis (OCAA). METHODS: Subgingival biofilm and coronary balloons used in percutaneous transluminal coronary angioplasty were collected from 18 subjects presenting with generalized moderate to severe periodontitis and OCAA. DNA was extracted and the gene 16S was amplified, cloned and sequenced. RESULTS: Significant differences in microbial diversity were observed between both environments. While subgingival samples mostly contained the phylum Firmicutes, in coronary balloons, Proteobacteria (p<0.05) was predominant. In addition, the most commonly detected genera in coronary balloons were Acinetobacter, Alloprevotella, Pseudomonas, Enterobacter, Sphingomonas and Moraxella, while in subgingival samples Porphyromonas, Filifactor, Veillonella, Aggregatibacter and Treponema (p<0.05) were found. Interestingly, 17 identical phylotypes were found in atheroma and subgingival samples, indicating possible bacterial translocation between periodontal pockets and coronary arteries. CONCLUSION: Periodontal pockets and atheromatous plaques of cardiovascular disease patients can present similarities in the microbial diversity.

Terapia periodontal regenerativa com proteína da matriz do esmalte associada com B tricálcio fosfato em área estética / Regerenative periodontal therapy with enamel matrix protein in association

A progressão da doença periodontal quando não tratada resulta na destruição dos tecidos periodontais, podendo levar a formação de defeitos infraósseos. Esses defeitos podem provocar um dano estético quando em região anterior. Este relato de caso visou demonstrar a utilização de duas abordagens regenerativas para o tratamento de defeitos infraósseos em área estética. Para um defeito, foi empregada a proteína da matriz do esmalte (Emdogain) e, no outro defeito, uma associação do Emdogain com β tricálcio fosfato/hidroxiapatita (Bone Ceramic). Após seis meses do tratamento, houve melhora clínica e radiográfica para ambas as abordagens.

Factors associated with the prevalence of periodontal disease in low-risk pregnant women.

OBJECTIVE: To evaluate the prevalence of periodontal disease (PD) among Brazilian low-risk pregnant women and its association with sociodemographic factors, habits and oral hygiene. METHOD: This cross-sectional study included 334 low-risk pregnant women divided in groups with or without PD. Indexes of plaque and gingival bleeding on probing, probing pocket depth, clinical attachment level and gingival recession were evaluated at one periodontal examination below 32 weeks of gestation. Independent variables were: age, race/color, schooling, marital status, parity, gestational age, smoking habit, alcohol and drugs consumption, use of medication, presence of any systemic diseases and BMI (body mass index). Statistical analyses provided prevalence ratios and their respective 95%CI and also a multivariate analysis. RESULTS: The prevalence of PD was 47% and significantly associated with higher gestational age (PR 1.40; 1.01-1.94 for 17-24 weeks and PR 1.52; 1.10-2.08 for 25-32 weeks), maternal age 25-29 years, obesity (PR 1.65; 1.02-2.68) and the presence of gingival bleeding on probing (OR(adj) 2.01, 95%CI 1.41-2.88). Poor oral hygiene was associated with PD by the mean values of plaque and bleeding on probing indexes significantly greater in PD group. CONCLUSIONS: The prevalence of PD is high and associated with gingival bleeding on probing, more advanced gestational age and obesity. A program of oral health care should be included in prenatal care for early pregnancy, especially for low-income populations.

Association of IL1 gene polymorphisms with chronic periodontitis in Brazilians.

UNLABELLED: Chronic periodontal disease (PD) is an infectious immune-inflammatory illness. Polymorphisms in IL1 genes play a role in inflammatory diseases through the modulation of cytokine levels. OBJECTIVE: this study aimed to investigate the association between polymorphisms in the IL1 gene cluster and chronic periodontitis in a Brazilian population. DESIGN: a sample of 113 subjects over 25 years (mean age 41.2) were grouped into: 44 healthy individuals, 31 subjects with moderate and 38 with severe periodontitis. DNA was obtained through a mouthwash and oral mucosa scraping. PCR-RFLP was used to identify the following polymorphisms: IL1A C-889T (rs1800587), IL1B C-511T (rs16944), IL1B C+3954T (rs11436340), IL1RN intron 2 (rs2234663). Differences in the allele/genotype/haplotype frequencies were assessed by Chi-square test (p<0.05). The risk associated with alleles, genotypes and haplotypes was calculated as odds ratio (OR) with 95% confidence intervals (CI). RESULTS: neither IL1A (C-889T) nor IL1B (C+3954T) polymorphisms was associated with chronic PD. Allele T for IL1B (C-511T) only associated with PD in the group of blacks and mulattos. Moreover, genotype 2/2 for IL1RN (intron 2) was associated with severe PD. CONCLUSIONS: genotype 2/2 of IL1RN for the whole Brazilian population and allele T of IL1B (C-511T) in a subgroup of Afro-Americans and mulattos were suggested as putative risk indicators for chronic periodontitis.

Periodontal disease and some adverse perinatal outcomes in a cohort of low risk pregnant women.

OBJECTIVE: To evaluate the association of periodontal disease (PD) in pregnancy with some adverse perinatal outcomes. METHOD: This cohort study included 327 pregnant women divided in groups with or without PD. Indexes of plaque and gingival bleeding on probing, probing pocket depth, clinical attachment level and gingival recession were evaluated at one periodontal examination below 32 weeks of gestation. The rates of preterm birth (PTB), low birth weight (LBW), small for gestational age (SGA) neonates and prelabor rupture of membranes (PROM) were evaluated using Risk Ratios (95%CI) and Population Attributable Risk Fractions. RESULTS: PD was associated with a higher risk of PTB (RRadj. 3.47 95%CI 1.62-7.43), LBW (RRadj. 2.93 95%CI 1.36-6.34) and PROM (RRadj. 2.48 95%CI 1.35-4.56), but not with SGA neonates (RR 2.38 95%CI 0.93 - 6.10). CONCLUSIONS: PD was a risk factor for PT, LBW and PROM among Brazilian low risk pregnant women.

Semilunar coronally positioned flap or subepithelial connective tissue graft for the treatment of gingival recession: a 30-month follow-up study.

BACKGROUND: The objective of this prospective, controlled clinical trial was to evaluate the long-term outcomes of subepithelial connective tissue graft (SCTG) or semilunar coronally positioned flap (SCPF) for the treatment of Miller Class I gingival recession defects. METHODS: Seventeen patients with bilateral Miller Class I gingival recessions (< or =4.0 mm) in maxillary canines or premolars were selected. The recessions were randomly assigned to receive SCPF or SCTG. Recession height (RH), recession width (RW), width of keratinized tissue (WKT), thickness of keratinized tissue (TKT), probing depth (PD), and clinical attachment level (CAL) were measured at baseline and at 6 and 30 months post-surgery. Patient satisfaction with esthetics and root sensitivity was also evaluated. RESULTS: The root-coverage outcomes obtained at 6 months were maintained throughout the study. At the 30-month examination, the average percentage of root coverage was 89.25% for SCPF and 96.83% for SCTG (P >0.05); complete root coverage was observed in 58.82% and 88.24% of patients, respectively. SCTG maintained a statistically significant increase in TKT (P <0.05) at 30 months. At this time, there were no significant differences between the two groups with regard to RH, RW, WKT, PD, and CAL. The evaluation of the esthetic outcome by the patient showed a preference for the SCTG treatment. Furthermore, in this group, no patient complained of residual or additional root hypersensitivity. In the SCPF group, three patients had this complaint at 30 months. CONCLUSIONS: SCPF and SCTG can be successfully used to treat Class I gingival recession, presenting outcomes with long-term stability. However, patient-oriented outcomes, such as esthetics and root sensitivity, favor SCTG therapy.

Evaluation of the incidence of preterm low birth weight in patients undergoing periodontal therapy.

BACKGROUND: Preterm low birth weight was reported to be related to periodontal infections that might influence the fetus-placenta complex. The aim of this study was to provide periodontal treatment for pregnant women and to evaluate if this treatment can interfere with pregnancy duration and weight of the newborn. METHODS: The sample consisted of 450 pregnant women who were under prenatal care at a polyclinic in Três Corações, Brazil. Women with risk factors, such as systemic alterations (ischemic cardiopathy, hypertension, tuberculosis, diabetes, cancer, anemia, seizure, psychopathology, urinary tract infection, sexually transmitted diseases, asthma, and human immunodeficiency virus), and/or users of alcohol, tobacco, and drugs were excluded from the study. Data related to age, socioeconomic level, race, marital status, number of previous pregnancies, and previous preterm delivery also were evaluated. Initially, the sample was divided into two groups: 122 healthy patients (group 1) and 328 patients with periodontal disease (group 2). In group 2, 266 patients underwent treatment and 62 patients dropped out. After mothers gave birth, pregnancy duration and the weight of all infants were analyzed and recorded. RESULTS: There was no statistical difference between the healthy and treated groups. However, there was a difference in the non-treated group, with a 79% incidence of preterm low birth weight. Educational level, previous preterm birth, and periodontal disease were related significantly to preterm delivery (P <0.001). CONCLUSION: Periodontal disease was related significantly to preterm low birth weight.

Comparative study of ultrasonic instrumentation for the non-surgical treatment of interproximal and non-interproximal furcation involvements.

BACKGROUND: The aim of this clinical trial was to compare the outcome of non-surgical treatment of interproximal and non-interproximal Class II furcation involvements. METHODS: Thirty-eight patients presenting at least one Class II furcation involvement that bled on probing with a probing depth (PD) > or = 5 mm were recruited. Furcation involvements were grouped as either buccal and lingual furcation involvements (BLFI) or interproximal furcation involvements (IFI). The following clinical outcomes were evaluated: visible plaque index, bleeding on probing (BOP), position of the gingival margin, relative attachment level (RAL), PD, and relative horizontal attachment level (RHAL). N-benzoyl-l-arginine-p-nitroanilide (BAPNA) testing was used to analyze trypsin-like activity in dental biofilm. All parameters were evaluated at baseline and 1, 3, and 6 months after non-surgical subgingival instrumentation. RESULTS: Six months after treatment, both groups had similar means of RAL and RHAL gain (P >0.05). These variables were 1.22 and 1.07 mm in the IFI group and 1.38 and 1.20 mm in the BLFI group, respectively. The PD reduction was significantly greater in the BLFI group than in the IFI group (2.59 and 2.11 mm, respectively; P <0.05). The BLFI group presented fewer sites with PD > or = 5 mm than the IFI group at all post-treatment periods. At 6 months, the BAPNA test showed that only the BLFI group had values significantly different from baseline. This means that the BLFI group had significantly lower BAPNA values compared to the IFI group at 6 months. CONCLUSION: Buccal and lingual Class II furcation involvements respond better to non-surgical therapy compared to interproximal Class II furcation involvements.

Selective cyclooxygenase-2 inhibitor may impair bone healing around titanium implants in rats.

BACKGROUND: The aim of this study was to investigate the effect of a selective cyclooxygenase-2 inhibitor, meloxicam, on bone healing around titanium implants in rats. METHODS: Thirty-one adult male Wistar rats were included in this study, and one screw-shaped titanium implant was inserted in the tibiae of each rat. The animals were randomly assigned to one of the following groups for daily subcutaneous injections: control (N = 14): saline solution; and test (N = 17): 3 mg/kg of meloxicam, each administered daily for 60 days. After the treatment, animals were sacrificed, and undecalcified sections were obtained. Bone-to-implant contact (BIC) and bone area (BA) within the limits of implant threads and bone density (BD) in a 500 mum-wide zone lateral to the implants were obtained and arranged for cortical (zone A) and cancellous (zone B) bone regions. RESULTS: Intergroup comparisons demonstrated that meloxicam significantly reduced bone healing around implants. For zone A, significant differences were observed regarding BIC (47.01 +/- 10.48 A; 35.93 +/- 12.25 B), BA (86.42 +/- 3.66 A; 61.58 +/- 12.09 B), and BD (96.86 +/- 0.96 A; 91.06 +/- 3.05 B) for control and test groups, respectively (P <0.05). For zone B, data analysis also showed significant differences among groups for BIC (30.76 +/- 13.80 A; 16.86 +/- 11.48 B), BA (34.83 +/- 8.18 A; 25.66 +/- 9.16 B), and BD (15.76 +/- 7.05 A; 7.73 +/- 4.61 B) for control and test groups, respectively (P <0.05). CONCLUSION: Meloxicam may negatively influence bone healing in the cortical and cancellous bone around titanium implants inserted in rats after continuous administration.

Root cementum modulates periodontal regeneration in Class III furcation defects treated by the guided tissue regeneration technique: a histometric study in dogs.

BACKGROUND: Because the possibility of root cementum preservation as an alternative approach for the treatment of periodontal disease has been demonstrated, this study aimed to histometrically evaluate the effect of root cementum on periodontal regeneration. METHODS: Bilateral Class III furcation defects were created in dogs, and each dog was randomly assigned to receive one of the following treatments: control (group A): scaling and root planing with the removal of root cementum; or test (group B): removal of soft microbial deposits by polishing the root surface with rubber cups and polishing paste, aiming at maximum cementum preservation. Guided tissue regeneration (GTR) was applied to both groups. RESULTS: Four months after treatment, a superior length of new cementum (3.59 +/- 1.67 mm versus 6.20 +/- 2.26 mm; P = 0.008) and new bone (1.86 +/- 1.76 mm versus 4.62 +/- 3.01 mm; P = 0.002) and less soft tissue along the root surface (2.77 +/- 0.79 mm versus 1.10 +/- 1.48 mm; P = 0.020) was observed for group B. Additionally, group B presented a larger area of new bone (P = 0.004) and a smaller area of soft tissue (P = 0.008). CONCLUSION: Within the limits of this study, root cementum may modulate the healing pattern obtained by guided tissue regeneration in Class III furcation defects.

Periodontal debridement with povidone-iodine in periodontal treatment: short-term clinical and biochemical observations.

BACKGROUND: The aim of the present study was to evaluate the clinical effects of one-stage periodontal debridement with an ultrasonic instrument, associated with 0.5% povidone (pvp)-iodine irrigation in patients with chronic periodontitis. METHODS: Forty-five patients were randomly assigned into three groups: the control group (CG) received quadrant root planing at 1-week intervals over four consecutive sessions; the periodontal debridement plus pvp-iodine group (PD-PIG) received a 45-minute full-mouth debridement with an ultrasonic instrument, associated with 0.5% pvp-iodine irrigation; and the periodontal debridement group (PDG) received a 45-minute full-mouth periodontal debridement with an ultrasonic instrument, associated with NaCl irrigation. RESULTS: At the 3-month evaluation, the mean probing depth (PD) reduction in CG was 2.51+/-0.52 mm, 2.53+/-0.50 mm in PD-PIG, and 2.58+/-0.60 mm in PDG (P<0.05). The clinical attachment level (CAL) analysis showed a statistically significant gain in all groups compared to baseline (1.87+/-0.56 mm [CG], 1.94+/-0.70 mm [PD-PIG], and 1.99+/-0.92 mm [PDG]). Intergroup analysis of PD and CAL at 1 and 3 months showed no differences (P>0.05). The N-benzoyl-L-arginine-p-nitroanilide (BAPNA) test showed a significant reduction in trypsin activity only during the first month (P<0.05); at 3 months there were no differences compared to baseline (P=0.80). CONCLUSION: This study provides no evidence that pvp-iodine is effective as an adjunct for one-stage periodontal debridement.

Comparative 6-month clinical study of a semilunar coronally positioned flap and subepithelial connective tissue graft for the treatment of gingival recession.

BACKGROUND: The purpose of this randomized clinical trial was to compare the outcome of gingival recession therapy using the semilunar coronally positioned flap (SCPF) or the subepithelial connective tissue graft (SCTG). METHODS: Seventeen patients with bilateral Miller Class I buccal gingival recessions (

Povidone-iodine used as an adjunct to non-surgical treatment of furcation involvements.

BACKGROUND: The aim of this clinical trial was to evaluate the effect of topically applied povidone-iodine (polyvinylpyrrolidone and iodine [PVP-I]) used as an adjunct to non-surgical therapy of furcation involvements. METHODS: Forty-four patients presenting at least one Class II furcation involvement that bled on probing with probing depth (PD)>or=5 mm were recruited. Patients were stratified into two treatment groups: 1) subgingival instrumentation by an ultrasonic device using PVP-I (10%) as the cooling liquid (test); and 2) identical treatment using distilled water as the cooling liquid (control). The following clinical outcomes were evaluated: plaque index, bleeding on probing (BOP), position of the gingival margin, relative attachment level (RAL), PD, and relative horizontal attachment level (RHAL). The N-benzoyl-L-arginine-p-nitroanilide (BAPNA) test was used to analyze the trypsin-like activity in dental biofilm. The clinical and biochemical parameters were evaluated at baseline and 1, 3, and 6 months after therapy. RESULTS: Both groups had similar means of PD reduction and RAL and RHAL gain. At 6 months, these variables were, respectively, 2.31, 1.17, and 1.00 mm in the control group and 2.31, 1.23, and 1.02 mm in the test group. There was also no difference between groups regarding the number of furcation sites presenting RAL gain>or=2 mm. The results of the BAPNA test failed to demonstrate significant differences between groups. CONCLUSION: Non-surgical therapy can effectively treat Class II furcation involvements, and the use of topically applied PVP-I as an adjunct to subgingival instrumentation does not provide additional benefits.

Bone filling around titanium implants may benefit from smoking cessation: a histologic study in rats.

BACKGROUND: Although a harmful effect of smoking on titanium implants has been documented, only a few studies have investigated the benefits of smoking cessation. Thus, this study histologically investigated whether smoking cessation influences bone healing around titanium implants and comparatively evaluated temporary versus complete cessation protocols. METHODS: Sixty-six male Wistar rats were randomly assigned to one of four groups: control (N = 16); CSI, intermittent cigarette smoke inhalation (CSI) throughout the entire 150-day experiment (N = 17); P-CSI, CSI 83 days prior to implant placement (N = 17); or R-CSI, CSI for 83 days, cessation 7 days before and 21 weeks after implant placement, and return to CSI for 39 days (N = 16). The animals were sacrificed and the degree of bone-to-implant contact (BIC) and the bone area (BA) within the limits of the implant threads obtained for cortical (zone A) and cancellous bone (zone B). RESULTS: Intergroup analysis (Kruskal-Wallis test, alpha = 0.05) demonstrated a significant effect of CSI on BA (P <0.05) and that temporary or complete CSI cessation protocols resulted in values similar to those of the control group (P >0.05) 88.91% +/- 4.29%; 80.66% +/- 6.55%; 84.27% +/- 6.96%; 85.71% +/- 4.7% in zone A, and 51.28% +/- 6.49%; 38.69% +/- 10.78%; 48.87% +/- 8.47%; 49.47% +/- 8.04%; in zone B for groups CTRL, CSI, P-CSI, and R-CSI, respectively. CONCLUSION: Within the limits of the present investigation, temporary and complete CSI cessation reversed the effect of smoke exposure on bone healing around titanium implants in both cortical and cancellous bone.

The effect of one session of supragingival plaque control on clinical and biochemical parameters of chronic periodontitis

O objetivo deste estudo foi avaliar o efeito do controle de placa supragengival sobre os parâmetros clínicos e bioquímicos da periodontite crônica. Foram selecionados 25 pacientes apresentando pelo menos 4 sítios com profundidade de sondagem > 5 mm, não fumantes e sem alteracões sistêmicas relevantes. A avaliacão clínica e bioquímica foi feita antes e 21 dias após a remocão dos fatores retentivos de placa, exodontia dos dentes condenados e instrucão de higiene bucal. A análise estatística foi feita através do teste t de Student pareado (p<0,05) e demonstrou reducão da porcentagem de sítios com sangramento à sondagem de 42,72 mais ou menos 15,83 para 35,87 mais ou menos 13,30 (p=0,002). Reducão na profundidade de sondagem foi observada nos dentes anteriores (média inicial/final: 2,88 mm/2,78 mm; p=0,01) e faces interproximais (média inicial/final: 3,80 mm/3,65 mm; p=0,001). Houve aumento de 66,81 por cento para 68,65 por cento (p=0,03) no número de sítios com profundidade de sondagem de 1 a 3 mm e reducão de 26,21 por cento para 24,17 por cento (p=0,04) nos de 4 a 6 mm. O valor do BAPNA apresentou reducão de 51,44 mais ou menos 20,78 para 38,64 mais ou menos 12,34 (p=0,04). Baseado nesses achados pôde-se concluir que o controle de placa supragengival tem efeitos benéficos, principalmente relacionados à reducão da inflamacão gengival e da atividade de enzima tipo tripsina no biofilme subgengival (BAPNA).

Smoking cessation may present a positive impact on mandibular bone quality and periodontitis-related bone loss: a study in rats.

BACKGROUND: It has been previously shown that cigarette smoke inhalation (CSI) enhances bone loss in ligature-induced periodontitis. In this study, the hypothesis that the interruption of smoke exposure would reverse the impact of CSI on mandibular bone quality and periodontitis-related bone loss was tested. METHODS: Fifty-three Wistar rats were randomly assigned to one of the following groups: group 1: control, N = 16; group 2: 83 days of CSI prior to ligature placement, N = 17; or group 3: 90 days of CSI before and 60 days after ligature placement, N = 20. Animals were sacrificed 60 days after ligature placement, the jaws removed and immediately radiographed for photodensitometry analysis. Bone loss was histometrically evaluated. RESULTS: CSI did not affect unligated sites in either condition (P >0.05); however, smoke inhalation during the whole experimental period significantly enhanced bone loss in ligated teeth (P < 0.05). Moreover, similar levels of bone loss were observed for ligated teeth between the control and cessation groups (0.90 +/- 0.33 mm(2); 0.96 +/- 0.32 mm(2); 1.64 +/- 0.65 mm(2); groups 1, 2 and 3, respectively). Radiographically, continuous exposure to cigarette smoke promoted a significantly reduced bone density (1.74 +/- 0.38 aluminum equivalence [Al eq]; 1.74 +/- 0.14 Al eq; and 0.68 +/- 0.10 Al eq for groups 1, 2, and 3, respectively). CONCLUSIONS: Within the limits of the present investigation, it can be assumed that CSI may enhance bone loss in ligature-induced periodontitis, and negatively impact mandibular bone quality. Additionally, smoke exposure cessation seems to reverse its impact on mandibular bone, and, therefore, may be of clinical relevance.

The effect of one session of supragingival plaque control on clinical and biochemical parameters of chronic periodontitis.

Supragingival plaque control is a requisite for the success of any periodontal procedure. However, little is know about the effect of this procedure alone on periodontitis. The aim of this study was to determine the effect of supragingival plaque control on clinical and biochemical parameters of chronic periodontitis. Twenty-five subjects exhibiting at least 4 pockets > 5mm, non-smokers and with no relevant systemic diseases, were selected for the study. The clinical and biochemical assessments were done before and 21 days after removal of plaque retentive factors, extraction of affected teeth and instruction in oral hygiene. The statistical analysis was done with the Student paired t-test (p<0,05) and demonstrated a reduction on the percentage of sites with bleeding on probing from 42.72 ± 15.83 to 35.87 ± 13.30 (p=0.002). Reduction in probing depth was detected on anterior teeth (initial/final mean: 2.88 mm/2.78 mm; p=0.01) and interproximal sites (initial/final mean: 3.80 mm/3.65 mm; p=0.001). There was an increase from 66.81% to 68.65% in the number of sites with probing depth of 1 to 3mm and a decrease from 26.21% to 24.17% in those with probing depth of 4 to 6mm. The BAPNA results showed a decrease from 51.44 ± 20.78 to 38.64 ± 12.34 (p=0.04). This study demonstrated that supragingival plaque control provides a reduction in gingival inflammation and alterations in the subgingival microflora detected by the BAPNA test.

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.

Attachment loss after scaling and root planing with different instruments. A clinical study.

OBJECTIVES: The aim of this study was to evaluate clinically the immediate effect of trauma from instrumentation after scaling and root planing with different instruments. MATERIAL AND METHODS: Ten subjects with moderate chronic periodontitis, presenting probing depths ranging from 3.5 to 6.5 mm on anterior teeth, upper and/or lower, were selected. Teeth were randomly assigned to one of the following groups: MC group--scaled and planed with Gracey mini-curettes (MiniFive); CC group--scaled and planed with Gracey conventional curettes. The selected teeth were probed with a computerized electronic probe, guided by an occlusal stent, and then subjected to scaling and root planing. Immediately following instrumentation, teeth were probed again. The difference between relative attachment level (RAL) immediately before and after instrumentation was considered as trauma from instrumentation. RESULTS: Intra-group analysis revealed statistically significant differences between RAL immediately before and after instrumentation in both groups (0.68 +/- 0.32 for MC group; and 0.83 +/- 0.41 for CC group--p < 0.05). However, inter-group analysis did not show a statistically significant difference in trauma from instrumentation caused by the different instruments. CONCLUSIONS: Within the limits of this study, it was concluded that root instrumentation causes an average trauma from instrumentation of 0.76 mm with no differences between the tested instruments.