Search

Titanium dioxide nanotubes (TiO2-nts) were incorporated into a glass ionomer cement (GIC) with improved mechanical properties and antibacterial activity. The aims of the present in vitro study were to define the elemental characterization, aluminum (Al) release rate, and initial working time for GIC reinforced with TiO2-nts, in an experimental caries model. TiO2-nts were incorporated into GIC powder components at 5% by weight, and compared with unblended GIC. Experimental approaches used energy-dispersive spectrometry (EDS), atomic absorption spectrophotometry (AAS), and brightness loss to define surface element properties, Al release rates, and initial working time, respectively. Statistical analysis was performed by 2-way ANOVA, Tukey's test, generalized linear models, and Student's t test (a = 0.05). EDS data analysis revealed that TiO2-nts incorporated into GIC had no significant impact on the typical elemental composition of GICs in an in vitro caries model. Regarding the demineralizing solution, GIC with TiO2-nt significantly decreased the Al release rate, compared with the control group (p < 0.0001). Moreover, TiO2-nt incorporated into GIC did not alter the initial working time of the material (p > 0.05). These findings add information to our scientific body of knowledge concerning the potential impact of TiO2-nt on the performance of conventional GICs.

Background: Cellular cementum, a mineralized tissue covering apical tooth roots, grows by apposition to maintain the tooth in its occlusal position. We hypothesized that resident cementocytes would show morphological changes in response to cementum apposition, possibly implicating a role in cementum biology., Methods: Mandibular first molars were induced to super-erupt (EIA) by extraction of maxillary molars, promoting rapid new cementum formation. Tissue and cell responses were analyzed at 6 and/or 21 days post-procedure (dpp)., Results: High-resolution micro-computed tomography (micro-CT) and confocal laser scanning microscopy showed increased cellular cementum by 21 dpp. Transmission electron microscopy (TEM) revealed that cementocytes under EIA were 50% larger than control cells, supported by larger pore sizes detected by micro-CT. Cementocytes under EIA displayed ultrastructural changes consistent with increased activity, including increased cytoplasm and nuclear size. We applied EIA to Hyp mutant mice, where cementocytes have perilacunar hypomineralization defects, to test cell and tissue responses in an altered mechanoresponsive milieu. Hyp and WT molars displayed similar super-eruption, with Hyp molars exhibiting 28% increased cellular cementum area versus 22% in WT mice at 21 dpp. Compared to control, Hyp cementocytes featured well-defined, disperse euchromatin and a thick layer of peripherally condensed heterochromatin in nuclei, indicating cellular activity. Immunohistochemistry (IHC) for cementum markers revealed intense dentin matrix protein-1 expression and abnormal osteopontin deposition in Hyp mice. Both WT and Hyp cementocytes expressed gap junction protein, connexin 43., Conclusion: This study provides new insights into the EIA model and cementocyte activity in association with new cementum formation., (© 2021 American Academy of Periodontology.)

The aim of this study was to tailor the deposition parameters of magnetron sputtering to synthetize tantalum oxide (Ta x O y ) films onto commercially pure titanium (cpTi) surface. The structural and optical properties, morphology, roughness, elemental chemical composition and surface energy were assessed. The impact of Ta x O y films on initial Streptococcus sanguinis adhesion was investigated. The morphology and spreading of pre-osteoblastic (MC3T3-E1) cells on a crystalline tantalum oxide film were evaluated. Ta x O y films with estimated thickness of 600 nm and different structures (amorphous or crystalline) were produced depending on the various oxygen flow rates and parameters used. X-ray diffraction analysis revealed that the 8 O 2 sccm (600 °C/400 W) group showed crystallization corresponding to the β-Ta 2 O 5 phase. Optical analysis showed that the 4 O 2 sccm (200 °C 300 W) to 8 O 2 sccm (600 °C 300 W) groups and 10 O 2 sccm (200 °C 300 W) group presented regular and large-amplitude interference oscillations, suggesting high optical homogeneity of the films. The crystalline β-Ta 2 O 5 coating showed higher roughness and surface energy values than the other groups (P < .05) and was biocompatible. Compared with cpTi, the amorphous and crystalline tantalum oxide films did not increase bacterial adhesion (P > .05). By tailoring the deposition parameters, we synthetized a crystalline β-Ta 2 O 5 coating that improved titanium surface properties and positively affected cell spreading and morphology, making it a promising surface treatment for titanium-based implants., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Aggressive periodontitis (AgP) is influenced by genetic factors. Recently, the single nucleotide polymorphisms (SNPs) rs1537415 (GLT6D1), rs6667202 (IL10), and rs1333048 (ANRIL) were associated with AgP in different European populations. However, these specific SNPs have not yet been determined in Brazilians. Therefore, this study investigated whether these SNPs previously associated with AgP could be replicated among Brazilians., Methods: The SNPs rs1537415, rs6667202, and rs1333048 were genotyped using 5'-nuclease allelic discrimination assay in AgP (n = 200), chronic periodontitis (CP, n = 190), and healthy patients (H, n = 196). Differences in allele and genotype frequencies were analyzed using chi-square tests and stepwise logistic regression., Results: The minor C allele of rs6667202 was less frequently detected in AgP patients (23.5%) when compared to non-AgP groups (H = 34.2% and CP = 30.3%; p < 0.01), making the SNP protective against AgP occurrence. Moreover, the final logistic model for AgP diagnosis included gender (p = 0.001) and the SNP rs6667202 (p < 0.001) as significant variables. The SNPs rs1537415 and rs1333048 did not show associations with AgP., Conclusion: Only the SNP rs6667202 was associated with AgP in a Brazilian population, being the minor C allele protective against AgP. Moreover, SNPs rs1333048 and rs1537415, previously associated with AgP in other population, was not validated to Brazilian population., (© 2018 American Academy of Periodontology.)

Objective: To evaluate clinical and radiographic characteristics in peri-implant marginal tissues in patients with a history of chronic periodontitis, rehabilitated using tissue-level or bone-level implants., Material and Methods: Using a split-mouth design, 20 patients with a history of chronic periodontitis were selected and received two different implants, tissue-level group (n = 20) and the bone-level group (n = 20). Peri-implant probing depth, relative peri-implant mucosal margin position, relative peri-implant clinical attachment level, peri-implant plaque index and peri-implant bleeding on probing were evaluated at prosthesis installation, 1, 3, 6, 12 and 24 months after implant loading. Radiographic marginal bone level was evaluated at implant insertion, prosthesis installation, 6 and 24 months after implant loading., Results: The mean difference of peri-implant marginal bone resorption from implant installation to 24 months in function was 0.75 ± 1.12 mm for the tissue-level group and 0.70 ± 0.72 mm for the bone-level group. No statistically significant difference was found between groups at all assessment periods for clinical and radiographic peri-implant evaluation., Conclusion: Under a rigid supportive therapy, both approaches performed likewise regarding clinical and radiographic parameters for rehabilitation of patients with a history of chronic periodontitis., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective: This randomized, blinded, placebo-controlled clinical trial compared the levels of interferon γ (IFN-γ), prostaglandin E2 (PGE2), and interleukin 6 (IL-6) in the gingival crevicular fluid (GCF) from generalized aggressive periodontitis (GAgP) patients treated with nonsurgical therapy associated or not with amoxicillin/metronidazole adjunctive., Method and Materials: Thirty-nine GAgP patients were followed during 6 months. The patients were randomly allocated to one of the groups: experimental (scaling and root planing plus 375 mg amoxicillin and 250 mg metronidazole for 7 days) and control (scaling and root planing + placebo). Probing pocket depth (PPD), relative clinical attachment level (rCAL), gingival margin position (GMP), and IL-6, IFN-γ, and PGE2 levels in GCF were evaluated at baseline, and at 3 and 6 months after treatment., Results: Both therapies promoted PPD reductions, rCAL gains, and recession in GMP at the end of the study, with the experimental group presenting an additional PPD reduction in fullmouth analysis and deep pockets at the 3- and 6-month follow-ups (P < .05). During the period of the study, only the experimental group promoted a reduction in PGE2 levels in deep pockets at 3 and 6 months, while IFN-γ and IL-6 levels remained unchanged. However, the differences in the immunologic parameters were not statistically significant among the groups., Conclusion: It can be concluded that amoxicillin/ metronidazole associated with nonsurgical therapy promotes an additional PPD reduction in the treatment of GAgP; however, this therapy did not promote additional benefits in the evaluated immunologic parameters.

Background and Objective: The evidence of effectiveness of metronidazole (Mtz) as an adjunct therapy to periodontal procedure in the treatment of patients with chronic periodontitis is not conclusive. The aim of this study was to compare the effect of Mtz (delivered locally as a gel or systemically as a tablet) as an adjunctive therapy with full mouth periodontal debridement (1 h of ultrasonic calculus/plaque removal) in smokers with chronic periodontitis., Material and Methods: This pilot study involved 30 smokers with at least six teeth with a clinical attachment loss of ≥ 5 mm and probing pocket depth (PPD) of ≥ 5 mm. They were randomly assigned into one of three groups (n = 10): (i) 3 g daily of placebo gel applied topically (using a dental tray with the gel overnight) + periodontal debridement; (ii) 3 g daily of a 15% Mtz benzoate gel applied topically (using a dental tray with the gel overnight) + periodontal debridement; and (iii) a daily single dose of 750 mg Mtz (Flagyl(®)) + periodontal debridement. Clinical parameters (visible plaque index, gingival bleeding index [GBI], relative attachment level and PPD) and quantitative analysis (by real-time polymerase chain reaction) of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Tannerella forsythia were assessed at baseline and at 1, 3 and 6 mo after periodontal debridement., Results: There was no statistically significant difference in the average GBI and visible plaque index values at baseline between the groups (p ≥ 0.05). There was no significant difference between groups in all parameters evaluated (p ≥ 0.05). Significant reductions in GBI at 3 and 6 mo were observed in all groups (p < 0.05). Significant reductions in both PPD and relative attachment level at 1, 3 and 6 mo were observed in all groups (p < 0.05). Significant reductions in bacterial levels at 7 and 30 d were observed in all groups (p < 0.05)., Conclusion: Adjunctive use of Mtz (gel or tablet) to periodontal debridement had similar clinical and microbiological improvement compared to treatment with placebo + periodontal debridement in smokers with chronic periodontitis up to 6 mo post-treatment. Further studies are necessary to confirm the clinical relevance of these findings., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The aim of this study was to evaluate, histometrically, the bone healing of the molar extraction socket just after cigarette smoke inhalation (CSI). Forty male Wistar rats were randomly assigned to a test group (animals exposed to CSI, starting 3 days before teeth extraction and maintained until sacrifice; n=20) and a control group (animals never exposed to CSI; n=20). Second mandibular molars were bilaterally extracted and the animals (n=5/group/period) were sacrificed at 3, 7, 10 and 14 days after surgery. Digital images were analyzed according to the following histometric parameters: osteoid tissue (OT), remaining area (RA), mineralized tissue (MT) and non-mineralized tissue (NMT) in the molar socket. Intergroup analysis showed no significant differences at day 3 (p>0.05) for all parameters. On the 7(th) day, CSI affected negatively (p<0.05) bone formation with respect to NMT and RA (MT: 36%, NMT: 53%, RA: 12%; and MT: 39%, NMT: 29%, RA: 32%, for the control and test groups, respectively). In contrast, no statistically significant differences (p>0.05) were found at days 10 and 14. It may be concluded that CSI may affect socket healing from the early events involved in the healing process, which may be critical for the amount and quality of new-bone formation in smokers.

Cowden syndrome, also known as multiple hamartoma syndrome, is a rare autosomal dominant disorder characterized by multiple hamartomas and a high risk of development of malignancy. Oral findings, such as papillomatous lesions and fibromas, are common features; however, a periodontal phenotype has not been reported previously. Therefore, this report presents a case of gingival overgrowth associated with Cowden syndrome, its successful surgical management, and the 12-month follow-up results. Additionally, we discuss the implications for clinicians. A 23-year-old woman was referred to the Department of Periodontics, Piracicaba Dental School, presenting with generalized gingival overgrowth. A detailed dental and medical history and clinical examination confirmed the systemic diagnosis of Cowden syndrome. Histology, radiographs, and clinical data document the entire clinical approach and follow-up. Clinically, there were minor signs of recurrence of gingival overgrowth in a 12-month period after gingivectomy; however, papular lesions reappeared in keratinized gingiva immediately after healing. No signs of bone loss related to the systemic condition were observed radiographically. Histologically, a dense connective tissue with a moderate chronic inflammatory infiltrate and epithelial acanthosis, which is characteristic of gingival hyperplasia, were demonstrated. Gingival overgrowth may occur as an oral phenotype related to Cowden syndrome and can be successfully treated by means of external bevel gingivectomy, followed by regular maintenance therapy, contributing to the patient's well-being, both functionally and esthetically.

This case series evaluated the clinical performance and patient-centered outcomes after a minimally invasive surgical technique (MIST) associated with enamel matrix protein derivative (EMD), for the treatment of intra-bony defects. Twelve patients presenting teeth with probing depth >or=5 mm and bleeding on probing associated with radiographic evidence of intra-bony defect were treated by MIST associated with EMD. Clinical parameters were measured at baseline, 3 and 6 months. Patient perception during the intraoperative period and during the first postoperative week was evaluated. The use of MIST with EMD promoted significant improvements in clinical parameters, minimal pain/discomfort and maximum esthetics satisfaction. Within of limits of the present study, it could be shown that MIST combined with EMD for the treatment of intra-bony defects promotes satisfactory clinical and patient-centered outcomes.

Background: The aim of this clinical study was to evaluate the treatment of gingival recession, associated with non-carious cervical lesions by a connective tissue graft (CTG) alone, or in combination with a resin-modified glass ionomer restoration (CTG+R)., Materials and Methods: Forty patients presenting Miller Class I buccal gingival recessions, associated with non-carious cervical lesions, were selected. The defects were randomly assigned to receive either CTG or CTG+R. Bleeding on probing (BOP), probing depth (PD), relative gingival recession (RGR), clinical attachment level (CAL) and cervical lesion height (CLH) coverage were measured at baseline and 45 days, and 2, 3 and 6 months after treatment., Results: Both groups showed statistically significant gains in CAL and soft tissue coverage. The differences between groups were not statistically significant in BOP, PD, RGR and CAL, after 6 months. The percentages of CLH covered were 74.88 +/- 8.66% for CTG and 70.76 +/- 9.81% for CTG+R (p>0.05). The estimated root coverage was 91.91 +/- 17.76% for CTG and 88.64 +/- 11.9% for CTG+R (p>0.05)., Conclusion: Within the limits of the present study, it can be concluded that both procedures provide comparable soft tissue coverage. The presence of the glass ionomer restoration may not prevent the root coverage achieved by CTG.

Objectives: The aim of this study was to evaluate the influence of the crown shape on the outcomes of root coverage procedures., Material and Methods: Eighty patients with Miller class I gingival recessions in maxillary canines or premolars were selected. The recession areas were treated using the subepithelial connective tissue grafting. The following clinical parameters were analyzed: crown length (CL) and width (CW), recession height and width, probing depth, clinical attachment level, width and thickness of the keratinized tissue and percentage of root coverage achieved. These measurements were recorded at baseline and 6 months after the surgical procedure. The CW/CL ratio was calculated for each tooth and the median obtained (0.83). Patients were then ranked into two groups, according to the shape of the tooth with gingival recession: Group A - square crown shape (CW/CL values above 0.83) and Group B - long and narrow crown shape (CW/CL values below 0.83)., Results: No statistically significant differences (p>0.05) were found between groups in any of the clinical parameters at baseline. After 6 months, both groups presented improved clinical outcomes for all parameters analyzed compared to baseline (p>0.05). The mean percentages and standard deviations of root coverage achieved in Group A and Group B was 91.37 (16.75) and 85.49 (23.55), respectively (p>0.05)., Conclusions: Crown shape did not influence the root coverage obtained with the subepithelial connective tissue graft technique.

Objective: This study assessed gene expression by quantitative polymerase chain reaction of inflammatory- [interleukin (IL)-12, tumor necrosis factor-alpha (TNF-alpha), IL-4, and IL-10] and osteoclastogenesis-related factors [receptor activator of NF-kappaB ligand (RANKL) and osteoprotegerin (OPG)] in sites exhibiting different severities of peri-implant disease., Material and Methods: Peri-implant soft tissue biopsies (n=48) were harvested from healthy implant (HI), mucositis (MC), initial peri-implantitis (IP) and severe peri-implantitis (SP) sites., Results: IL-12 and TNF-alpha mRNA levels were higher in SP, followed by IP and MC (P <0.05). IL-4 was higher in HI, followed by MC, SP and IP (P <0.05). IL-10 was the lowest in HI, while no differences were detected among the diseased groups (P>0.05). OPG mRNA levels were higher in HI, followed by IP, SP and MC, whereas RANKL was increased as the peri-implantitis severity increased (P<0.05). The highest OPG/RANKL ratio was observed in HI and the lowest in SP (P<0.01)., Conclusion: These findings suggest that expressions of inflammatory- and osteoclastogenesis-related factors may play an important role in the onset and severity of the peri-implant diseases.

Objective: The aim of this study was to evaluate histometrically bone healing in surgically created dehiscence-type defects around titanium implants treated with an association of platelet-rich plasma (PRP) and guided bone regeneration (GBR)., Materials and Methods: Ten male adult mongrel dogs were used, from which the three low premolars (P2, P3, P4) and the first molar were extracted. Three months after teeth extraction, two implant sites were bilaterally drilled, buccal bone dehiscences were created and four titanium implants were placed. Dehiscences were randomly assigned to the following groups: (1) PRP, (2) GBR, (3) PRP+GBR and (4) control. After 3 months, the animals were sacrificed and the implants and adjacent hard tissues were processed for undecalcified sections. Bone-to-implant contact (BIC), bone density within the limits of implant threads (BW), bone density (BD) and new bone area (BA) in a zone lateral to the implant corresponding to bone defects were obtained and measured., Results: Intergroup analysis (two-way ANOVA -alpha=5%) demonstrated that when PRP was utilized,no differences were observed for all parameters (P>0.05). However, significant differences were observed for BIC and BW toward membrane-treated groups (P<0.05)., Conclusion: Within the limits of this study, it was concluded that PRP does not exert additional effects on bone healing in bone defects created around dental implants and treated by GBR.

Objective: The aim of the present study was to evaluate whether a stent should be used when assessing attachment level (AL) by an electronic probe (Florida Probe)., Methods: Twenty patients were recruited and individual stents were obtained to measure relative AL (RAL) with the Florida stent probe. Conventional AL (CAL) measurements were obtained by adding pocket depth and gingival recession recorded by the Florida pocket probe. Duplicate RAL and CAL measurements were taken one hour apart from each other on anterior teeth, at six sites per tooth, by one examiner. Patients were treated and reassessed with both probes after 45 days so that the gain in RAL and CAL could also be compared., Results: Pearson's correlation test showed that correlation was moderate (r = 0.57) and significant (p < 0.001) for duplicate CAL measurements. As for RAL values, correlation was higher (0.91) and significant (p < 0.001). The difference between RAL and CAL gain after 45 days was 0.04 mm (p = 0.85)., Conclusion: Since the correlation was higher for duplicate RAL measurements than for CAL measurements, the use of a stent should be considered in clinical trials to ensure better reproducibility of measurement of attachment level gains.

The continuous search for improved surgical procedures to address gingival deformities is a consequence of an increasing demand for aesthetics in the periodontal clinical practice. Innovative techniques have been reported to help clinicians achieve predictability in root coverage. Significant progress can be attributed to the inclusion of the operative microscope in periodontal therapy, particularly in regards to obtaining primary closure. This article describes a microsurgical technique used to treat gingival recessions, showing its potential for obtaining optimal aesthetic results.

Objective: The purpose of this study was to evaluate the root surface roughness after instrumentation with hand curette and diamond-coated sonic and universal ultrasonic tips., Materials and Methods: Forty root surfaces of human teeth were randomly assigned to four treatment groups: control group (without instrumentation), curette instrumentation, ultrasonic instrumentation with universal tip and sonic instrumentation with diamond-coated tip. Each sample was instrumented with fifteen strokes. Before and after instrumentation, surface roughness was measured. In addition, the root surface topography was examined after treatment under the scanning electron microscope., Results: Significant statistical differences (p <0.05) were observed when comparing the control group (0.48+/-0.07mm) to the treated groups (hand - 1.246+/-0.279mm, ultrasonic - 1.468+/-0.177mm and sonic instrumentation - 1.576+/-0.20mm). The highest roughness was produced by diamond-coated sonic tip and by ultrasonic universal tip (p >0.05)., Conclusion: The diamond-coated tip with sonic scaler instrumentation and ultrasonic instrumentation produce similar root surface roughness, higher than curette instrumentation.

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.

Background: Cigarette smoking has been shown to negatively influence healing following periodontal therapeutic procedures. Therefore, the aim of this study was to evaluate the impact of smoking on clinical outcome of root coverage following subepithelial connective tissue graft (CTG) surgery., Methods: Eighteen defects were treated in 15 patients (seven smokers and eight non-smokers) who presented canine and pre-molar Miller Class I and II recessions. CTG was performed and clinical measurements were obtained at baseline, and 30, 60, 90, and 120 days after surgery. Clinical measurements included plaque and gingival indexes, gingival recession, probing depth, clinical attachment level, gingival thickness, and keratinized tissue width., Results: Intragroup analysis showed that CTG was able to promote root coverage, increase gingival thickness, and improve clinical attachment level in both groups (P < 0.05). On the other hand, intergroup analysis demonstrated that smokers presented with a lower percentage of root coverage (58.84% +/- 13.68% versus 74.73% +/- 14.72%), less clinical attachment level gain (2.54 +/- 0.79 mm versus 2.00 +/- 1.04 mm), and deeper probing depths (1.56 +/- 0.53 mm versus 2.35 +/- 0.67 mm) than non-smokers (P < 0.05). Moreover, 4 months after CTG, smokers presented more keratinized tissue compared to non-smokers (3.30 +/- 0.86 mm versus 4.50 +/- 1.16 mm) (P < 0.05)., Conclusion: Within the limits of the present study, it can be concluded that cigarette consumption may present a negative impact on root coverage outcome by CTG and, therefore, may represent one more challenge for periodontal plastic therapy.

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.

Purpose: To evaluate, histometrically, the healing of gingival recessions treated by coronally positioned flaps associated with enamel matrix protein derivative (EMD-Group) and to compare it to that obtained with coronally positioned flaps alone (CPF-Group)., Methods: Five mongrel dogs were used. Gingival recessions were surgically created on the buccal aspect of the upper cuspids. The defects (5 x 7 mm) were exposed to plaque accumulation for 3 months. After a preparation period, the contralateral defects were randomly assigned to each group. After 3 months of healing, the dogs were sacrificed and the blocks were processed. The histometric parameters evaluated included: gingival recession, length of epithelium, new connective tissue attachment and new bone., Results: The gingival recession was -0.1 +/- 0.2 mm for the EMD-Group and -0.8 +/- 1.3 mm for the CPF-Group (P = 0.17). The extension of the epithelium was 1.2 +/- 1.0 mm for the EMD-Group and 1.3 +/- 0.7 mm for the CPF-Group (P = 0.89). The new connective tissue attachment was 4.8 +/- 0.7 in the EMD-Group and 4.0 +/- 1.4 in the CPF-Group (P = 0.22). The new bone was 0.1 +/- 1.8 mm and -0.5 +/- 1.4 mm in the EMD-Group and CPF-Group, respectively (P = 0.50). Histologically, the defect coverage observed was 98.2% for the EMD-Group and 85.8% for the CPF-Group.

The aim of this study was to evaluate the influence of the administration and withdrawal of cyclosporin A/nifedipine on the bone density in a lateral area adjacent to implants placed in rabbits. Two screw-type titanium implants were placed bilaterally in twenty-eight New Zealand rabbits. The animals were assigned to one of the following groups and received daily subcutaneous injections for 14 days: Groups A and C: vehicle (dimethyl sulfoxide); Groups B and D: CsA (10 mg/kg) plus nifedipine (50 mg/kg). The animals in Groups A and B were sacrificed 14 days postoperatively and, in Groups C and D, 42 days postoperatively. After sacrifice, the tibiae were removed and undecalcified sections were obtained. Bone density was obtained in a 500 mm-wide zone lateral to the implant surface. Intergroup analysis showed no significant difference (p > 0.05) in the degree of bone density between control and test groups either on day 14 or on day 42. Thus, it appears that a short-term immunosuppressive therapy may not present a negative influence on the density of the pre-existing bone around titanium implants placed in rabbits.

Purpose: To evaluate the treatment outcomes after guided tissue regeneration (GTR) with a bioabsorbable membrane in Class II furcation defects in mandibular molars. The open flap debridement (OFD) was used as the control., Methods: Nine patients, with two comparable Class II furcation defects were included in the study. After initial preparation, the defects were randomly assigned in each patient to either GTR-group or OFD-group. Clinical parameters and standardized radiographs were obtained at baseline and 6 months after the surgeries. The radiographs were analyzed by subtraction radiography., Results: Comparing baseline to 6-month results, both groups showed statistically significant probing depth reduction (PD), horizontal clinical attachment level (CAL-h) gain, and increase in gingival recession (GR). The vertical clinical attachment level (CAL-v) gain was statistically significant only for the OFD-group. Comparing the two treatments, no statistically significant differences were found in PD reduction (GTR: 1.67 mm; OFD: 2.51 mm, P = 0.26), CAL-v gain (GTR: 0.62 mm; OFD: 1.16 mm, P= 0.37), and GR increase (GTR: 1.04 mm; OFD: 1.24 mm, P = 0.31). GTR provided complete closure of the furcation defect in two sites and superior horizontal clinical attachment level gain (GTR: 2.27 mm; OFD: 1.01 mm, P = 0.05). Subtraction radiography showed significant difference in bone height change between GTR-group and OFD-group (-0.14 mm and 0.86 mm, respectively; P = 0.028) at 6 months.

Two case reports are presented in which the radiographic characteristics induced initially incorrect diagnoses. Only after combined clinical and radiographic examinations were the appropriate diagnoses achieved. This article demonstrates the need for close cooperation between periodontists and endodontists to diagnose periradicular lesions accurately.

Immunosuppressive agents have been recognized as a factor affecting the soft tissues of the periodontium. However, little is known about their effect on periodontitis progression. The aim of the present study was to investigate the influence of cyclosporin A (CsA) administration, associated or not with nifedipine, on the bone loss resulting from a ligature-induced periodontitis in rats. Twenty-four adult male Wistar rats were used. After anesthesia, the mandibular first molar was randomly assigned to receive the cotton ligature in the sulcular area while the contralateral tooth was left unligated. The animals were randomly assigned to one of the following treatments: Group A--saline solution; Group B--CsA (10 mg/kg); Group C--nifedipine (50 mg/kg); Group D--CsA (10 mg/kg) plus nifedipine (50 mg/kg). Forty-five days later, the animals were sacrificed and the specimens routinely processed for serial decalcified sections. Intergroup analysis did not reveal significant differences regarding the bone loss volume in the ligated teeth between the experimental treatments (0.46 +/- 0.11, 0.63 +/- 0.32, 0.53 +/- 0.14, 0.50 +/- 0.18, for groups A, B, C and D, respectively--p > 0.05). However, intragroup analysis showed a greater bone loss volume in the ligated teeth than in the unligated ones (p < 0.05). Within the limits of the present study, the conclusion was that the administration of CsA, associated or not with nifedipine, may not influence bone loss in ligature-induced periodontitis in rats.

Background: A negative influence of smoking on implant outcomes has been reported. This animal study investigated the influence of cigarette smoke on osseointegration and newly formed bone within implant threads., Methods: Male Wistar rats were included in the study. After anesthesia, the tibiae surface was exposed and a screw-shaped titanium implant (4.0 mm in length; 2.2 mm in diameter) was placed bilaterally. The animals were randomly assigned to group 1, control, or group 2, intermittent cigarette smoke inhalation. The animals were sacrificed after 60 days and undecalcified sections obtained. The degree of bone-to-implant contact (BIC) and the bone area (BA) within the implant threads were measured in the cortical (zone A) and cancellous bone (zone B) areas., Results: A slight difference in the BIC was noted between the groups, but this was not statistically significant either in zone A or in zone B (Mann-Whitney test, P > 0.05). In contrast, the BA close to the implant significantly decreased in both zones for group 2 (84.73% +/- 4.77 versus 79.85% +/- 6.17, zone A in groups 1 and 2, respectively, and 32.01% +/- 6.62 versus 20.71% +/- 8.57, zone B in groups 1 and 2, respectively, P < 0.05)., Conclusion: Within the limits of the present study, intermittent cigarette smoke inhalation may result in a poor bone quality around titanium implants inserted in rats.

Background: Immunosuppressive agents have been recognized as a factor affecting bone metabolism. We investigated the consequences of the administration and withdrawal of cyclosporin A/nifedipine on bone around titanium implants to observe whether these changes occur and if they are reversible., Methods: Twenty-eight New Zealand rabbits were included in the study. Following anesthesia, the tibiae surface was exposed, and 2 screw-shaped implants 7.0 mm in length and 3.75 mm in diameter were placed bilaterally. The animals were randomly assigned to 1 of 4 experimental groups and received daily subcutaneous injections for 14 days: groups A and C were injected with vehicle while groups B and D received cyclosporin A (10 mg/kg) plus nifedipine (0.5 mg/kg). Groups A and B were sacrificed 14 days and groups C and D 42 days postoperatively. The degree of bone contact with the implant surface and the bone area within the limits of the threads of the implant were measured., Results: Intergroup analysis revealed no significant difference (P > 0.05) in the degree of bone contact with the implant surface between the control and test groups on days 14 and 42. In contrast, the treated animals demonstrated a significant (P < 0.05) decrease in the bone area within the limits of the threads of the implant in both periods., Conclusions: The data of the present study suggest that the use of cyclosporin A/nifedipine may influence bone healing around titanium implants. This observation may have important clinical implications.

Irregularities of the cervical margin of restorations facilitate the retention of bacterial plaque, hindering plaque control through the habitual procedures of oral hygiene and favoring the development of periodontal disease. The aim of this study was to evaluate the periodontal condition and treatment needs (applying CPITN) in relation to the cervical margin of dental restorations. Three hundred and sixty-seven teeth with class II and V cavities restored with amalgam, class III cavities restored with composite resin, cast metal restorations and unitary prostheses were examined. With a WHO periodontal probe, the position of the cervical margins of restorations was verified (supragingival, subgingival or at the gingival margin level); the presence of defects (lack or excess of restoring material) and the presence of score 2 of CPITN were also assessed. After the analysis of the data, it was possible to conclude that: 1) supragingival margins offered the best marginal adaptation and the lowest frequency of score 2; 2) both the lack and the excess of restoring material favor the development of score 2, despite the utilized material and 3) in subgingival margins, incorrect marginal adaptation was the most frequent event, mainly due to excess of restoring material, and in these cases there was higher frequency of score 2 of CPITN.

This study evaluated, by clinical analysis, the hard tissue response following treatment of ligature-induced peri-implantitis defects in 5 dogs. The mandibular premolars were removed from both sides of the jaw. After 3 months of healing, two titanium implants were placed on each side of the mandible. Following abutment connection, 3 months later, experimental peri-implantitis was induced by the placement of cotton ligatures in a submarginal position. Ligatures and abutments were removed after one month and the bony defects were randomly assigned to one of the following treatments: debridement (DE), debridement plus guided bone regeneration (GBR), debridement plus mineralized bone graft (BG) and debridement plus guided bone regeneration associated with mineralized bone graft (GBR + BG). The peri-implant bone defects were clinically measured before and 5 months post-treatment. Results showed a higher percentage of vertical bone fill for GBR + BG (27.77 +/- 14.07) followed by GBR (21.78 +/- 16.19), BG (21.26 +/- 6.87), DE (14.03 +/- 5.6). However, there were no statistically significant differences between any of the treatments proposed (one way repeated measures analysis of variance, P = 0.265).

The purpose of this study was to evaluate, by histometric analysis, re-osseointegration following treatment of ligature-induced peri-implantitis in dogs. Five dogs were used in this study. Their mandibular premolars (P2, P3 and P4) were first removed. After 3 additional months of healing, two titanium implants were placed on each side of the mandible. After 3 months, the abutment connection was performed and experimental peri-implantitis was induced by placing cotton ligatures in a submarginal position. Ligatures and abutments were removed after one month and the peri-implant bone defects were randomly assigned to one of the treatments: debridement, debridement plus guided-bone regeneration, debridement plus mineralized-bone graft, and debridement plus guided-bone regeneration associated with mineralized-bone graft. Five months post-treatment, the degree of bone contact with the implant surface and the bone area within the threads were measured in 12 threads, the 6 most coronal at each side of each implant. One-way analysis of variance did not reveal statistically significant differences between the treatment modalities (p > 0.05). Within the limits of the present study, it can be concluded that there is a limited possibility of re-osseointegration around implant surfaces previously exposed by ligature-induced peri-implantitis.

Bone regeneration was evaluated around immediate implants partially in contact with bone, with or without the concurrent application of a combination of platelet-derived growth factor (PDGF) and insulin-like growth factor (IGF-1). Mandibular premolars were removed, and the implant osteotomies were prepared; a uniform circumferential gap was prepared 1.25 mm beyond the width of the implant bed in the coronal half. Twelve implants (8.5 x 3.75 mm) were inserted in six dogs. Before insertion, an implant received a single application of 5 micrograms/mL of PDGF and IGF-1 delivered in 0.10 mL of 4% methylcellulose gel or 0.10 mL of 4% methylcellulose gel only as a control. To label regenerated bone, a 2% calcein green solution was administered by intramuscular injection at 0, 7, 15, 30, and 45 days after implant insertion Three and 8 weeks after implant insertion undecalcified sections were obtained, and the degree of bone to implant contact, the bone area, and the intensity of bone labeling were measured into the limits of the eight most coronal threads of the implant (four threads on each side of each implant). The results showed a greater extension of bone-to-implant contact, a larger percentage of bone area, and greater intensity of bone labeling for test versus control implants (P < .01). Within the limits of the present study, it was concluded that the combination of PDGF/IGF-1 might be an alternative for enhancing bone healing around implants partially in contact with bone.

We carried out a clinical evaluation of the hard tissue fill following treatment of ligature-induced peri-implantitis in dogs. Four dogs were used and their mandibular premolars (P2, P3 and P4) were removed. After 3 months of healing, two titanium implants were placed on each side of the mandible. After 3 months, the abutment connection was performed, and experimental peri-implantitis was induced by placement of cotton ligatures in a submarginal position. The ligatures and abutments were removed after one month, and the peri-implant bone defects were assigned randomly to one of the treatments: debridement (control), debridement plus guided bone regeneration (GBR), debridement plus mineralized bone graft (BG), and debridement plus guided bone regeneration associated with a mineralized bone graft (GBR + BG). Clinical measurements of the peri-implant bone defects before and 5 months after treatment revealed no statistically significant differences between the defects treated by GBR, BG and GBR + BG. These 3 treatment methods provided more hard tissue fill than debridement alone (p < 0.05). Thus, it can be concluded that GBR, BG or a combination of the two techniques can enhance the hard tissue fill in defects caused by peri-implantitis in dogs.

The success achieved by Scandinavian researchers in the development of long-term implants has stimulated many dentists to apply them worldwide. However, most of the implants did not have sufficient scientific support. The purpose of this study was to evaluate host tissue response to the insertion of an endosseous dental implant. Twenty adult New Zealand rabbits were used. Histological evaluation was prepared from the femurs. Results showed a hemorrhagic aspect and inflammatory infiltration which was subsequently substituted by granulation tissue, and later, formation of bone tissue. In the cortical bone, the presence of a necrotic area was observed which was later remodelled, and also an intense proliferation of endosteum and periosteum in the regions next to the implant, resulting in a thickening of the cortical bone surface close to the implant. Therefore, it was observed that titanium implants (Carbontec-Special Materials Ltda.) did not interfere with the bone healing process.