Patricia Ramos Cury

A Finite Element Analysis of Two Different Dental Implants: Stress Distribution in the Prosthesis, Abutment, Implant, and Supporting Bone

This study evaluates the influence of 2 commercially available dental implant systems on stress distribution in the prosthesis, abutment, implant, and supporting alveolar bone under simulated occlusal forces, employing a finite element analysis. The implants and abutments evaluated consisted of a stepped cylinder implant connected to a screw-retained, internal, hexagonal abutment (system 1) and a conical implant connected to a solid, internal, conical abutment (system 2). A porcelain-covered, silver-palladium alloy was used as a crown. In each case, a simulated, 100-N vertical load was applied to the buccal cusp. A finite element model was created based on the physical properties of each component, and the values of the von Mises stresses generated in the prosthesis, abutment, implant, and supporting alveolar bone were calculated. In the prostheses, the maximum von Mises stresses were concentrated at the points of load application in both systems, and they were greater in system 1 (148 N/mm2) than in system 2 (55 N/mm2). Stress was greater on the abutment of system 2 than of system 1 on both the buccal (342 N/mm2 x 294 N/mm2) and lingual (294 N/mm2 x 148 N/ mm2) faces. Stress in the cortical, alveolar bone crest was greater in system 1 than in system 2 (buccal: 99.5 N/mm2 x 55 N/mm2, lingual: 55 N/mm2 x 24.5 N/mm2, respectively). Within the limits of this investigation, the stepped cylinder implant connected to a screw-retained, internal hexagonal abutment produces greater stresses on the alveolar bone and prosthesis and lower stresses on the abutment complex. In contrast, the conical implant connected to a solid, internal, conical abutment furnishes lower stresses on the alveolar bone and prosthesis and greater stresses on the abutment.

Accuracy and Complications of Computer‐Designed Selective Laser Sintering Surgical Guides for Flapless Dental Implant Placement and Immediate Definitive Prosthesis Installation

BACKGROUND Computer-aided dental implant placement seems to be useful for placing implants by using a flapless approach. However, evidence supporting such applications is scarce. The aim of this study is to evaluate the accuracy of and complications that arise from the use of selective laser sintering surgical guides for flapless dental implant placement and immediate definitive prosthesis installation. METHODS Sixty implants and 12 prostheses were installed in 12 patients (four males and eight females; age range: 41 to 71 years). Lateral (coronal and apical) and angular deviations between virtually planned and placed implants were measured. The patients were followed up for 30 months, and surgical and prosthetic complications were documented. RESULTS The mean ± SD angular, coronal, and apical deviations were 6.53° ± 4.31°, 1.35 ± 0.65 mm, and 1.79 ± 1.01 mm, respectively. Coronal and apical deviations of <2 mm were observed in 82.67% and 58.33% of the implants, respectively. The total complication rate was 34.41%; this rate pertained to complications such as pulling of the soft tissue from the lingual surface during drilling, insertion of an implant that was wider than planned, implant instability, prolonged pain, midline deviation of the prosthesis, and prosthesis fracture. The cumulative survival rates for implants and prostheses were 98.33% and 91.66%, respectively. CONCLUSIONS The mean lateral deviation was <1.8 mm, and the mean angular deviation was 6.53°. However, 41.67% of the implants had apical deviation >2 mm. The complication rate was 34.4%. Hence, computer-aided dental implant surgery still requires improvement and should be considered as in the developmental stage.

The impact of a 17-day training period for an international championship on mucosal immune parameters in top-level basketball players and staff members.

This investigation examined the impact of a 17-d training period (that included basketball-specific training, sprints, intermittent running exercises, and weight training, prior to an international championship competition) on salivary immunoglobulin A (SIgA) levels in 10 subjects (athletes and staff members) from a national basketball team, as a biomarker for mucosal immune defence. Unstimulated saliva samples were collected at rest at the beginning of the preparation for the Pan American Games and 1 d before the first game. The recovery interval from the last bout of exercise was 4 h. The SIgA level was measured using enzyme-linked immunosorbent assay and expressed as absolute concentrations, secretion rate, and SIgA level relative to total protein. The decrease in SIgA levels following training was greater in athletes than in support staff; however, no significant differences between the two groups were detected. A decrease in SIgA level, regardless of the method used to express IgA results, was verified for athletes. Only one episode of upper respiratory tract illness symptoms was reported, and it was not associated with changes in SIgA levels. In summary, a situation of combined stress for an important championship was found to decrease the level of SIgA-mediated immune protection at the mucosal surface in team members, with greater changes observed in the athletes.

Salivary immunoglobulin a response to a match in top-level brazilian soccer players.

Moreira, A, Arsati, F, Cury, PR, Franciscon, C, Oliveira, PR, and Araújo, VC. Salivary immunoglobulin a response to a match in top-level brazilian soccer players. J Strength Cond Res 23(7): 1968-1973, 2009-It has been suggested that several parameters of mucosal immunity, including salivary immunoglobulin A (s-IgA), are affected by heavy exercise either in field sports or in the laboratory environment. Few observations have been made during a true sporting environment, particularly in professional soccer. We tested the hypothesis that salivary IgA levels will be decreased after a 70-minute regulation in a top-level professional soccer friendly match. Saliva samples from 24 male professional soccer players collected before and after the match were analyzed. Salivary immunoglobulin A concentration was measured by enzyme-linked immunosorbent assay and expressed as the absolute concentration (s-IgAabs), s-IgA relative to total protein concentration (IgA-Pro), and the secretion rate of IgA (s-IgArate). Rate of perceived exertion (RPE) was used to monitor the exercise intensity. The paired t-test showed no significant changes in s-IgAabs and s-IgArate (p > 0.05) from PRE to POST match. However, a significant (p < 0.05) increase in total protein concentration (1.46 ± 0.4 to 2.00 ± 07) and a decrease in IgA-Pro were observed. The best and most significant correlation was obtained with the RPE and changes in IgA-Pro (rs = −0.43) and could indicate that this expression may be an interesting marker of intensity in a soccer match. However, further investigation regarding exercise intensity, protein concentration, and immune suppression, particularly in team sports, is warranted. From a practical application, the variability of the responses among the players leads us to suggest that there is a need to individually analyze the results with team sports. Some athletes showed a decrease in s-IgA expressions, suggesting the need for taking protective actions to minimize contact with cold viruses or even reducing the training load.

β-Catenin and E-Cadherin Expression in Salivary Gland Tumors

This study evaluated the expression of E-cadherin and β-catenin in salivary gland tumors. Twelve biopsy specimens from cases diagnosed as pleomorphic adenoma, 17 adenoid cystic carcinomas, 10 epithelial-myoepithelial carcinomas, and 4 polymorphous low-grade adenocarcinomas were immunohistochemically labeled for E-cadherin and β-catenin antibodies. Healthy salivary glands were used as controls. Membrane-associated E-cadherin and β-catenin expression was present in all the tumor types studied. E-cadherin and β-catenin showed a similar distribution; however, β-catenin labeling was weaker than that for E-cadherin. In the epithelial-myoepithelial carcinomas, myoepithelial cells exhibited diffuse nuclear staining, although occasional cells presented only focal labeling. Epithelial-myoepithelial carcinomas present changes in [.beta]-catenin expression but the other salivary tumors studied do not, which may reflect divergence in tumorigenesis of this extensive subset of salivary gland tumors.

Severe Periodontitis Is Associated With Diastolic Blood Pressure Elevation in Individuals With Heterozygous Familial Hypercholesterolemia: A Pilot Study

BACKGROUND This pilot study evaluates the association of severe periodontitis with pulse wave velocity (PWV), carotid artery intima-medial thickness (IMT), and clinical, metabolic, and atherogenic inflammatory markers in 79 subjects with heterozygous familial hypercholesterolemia (hFH). All subjects were free of previous vascular disease manifestations. METHODS The body mass index (in kilograms per square meter), plasma lipids, glucose, C-reactive protein, and white blood cell counts were evaluated. After full-mouth periodontal examinations, patients were categorized into the severe periodontitis group (SPG) or non-severe periodontitis group (NSPG). RESULTS The SPG showed significantly higher values of cholesterol-year scores, triglycerides, glucose, PWV, IMT, and diastolic blood pressure (DBP) (P ≤0.05) than the NSPG. After adjustment for traditional risk factors for atherosclerosis, only the association between severe periodontitis and DBP (odds ratio: 3.1; 95% CI: 1.1 to 8.5; P = 0.03) was confirmed. CONCLUSION In individuals with hFH, severe periodontitis was associated with a higher DBP, which suggests that severe periodontitis, itself, may contribute to the increased cardiovascular risk profile in this population.

Human Papillomavirus-16 Prevalence in Gingival Tissue and Its Association With Periodontal Destruction: A Case-Control Study

BACKGROUND Human papillomavirus (HPV)-16 is detected in normal oral mucosa and several oral lesions, including squamous cell carcinoma, condyloma acuminatum, verruca vulgaris, focal epithelial hyperplasia, and periodontal diseases. It was hypothesized that HPV may be involved in periodontal breakdown and that periodontal tissue acts as a reservoir for the virus. Therefore, in this study, the prevalence of HPV-16 in the gingival tissue of Brazilians with periodontal health or disease is investigated. METHODS Fifty-six gingival samples from subjects with chronic periodontitis, 26 samples from subjects with gingivitis, and 22 samples from subjects with healthy peridontium were analyzed. Total DNA was extracted, and the presence of HPV-16 was assessed using a real-time polymerase chain reaction. Positive and negative controls were included in the reactions. RESULTS HPV-16 was not detected in any of the 104 gingival samples evaluated; therefore, this virus showed no association with periodontal disease in this study. CONCLUSION In the population studied, HPV-16 may not have participated in the pathogenesis of chronic periodontitis, and the gingival tissue did not act as a reservoir for this virus.

Use of Anorganic Bovine-Derived Hydroxyapatite Matrix/Cell-Binding Peptide (P-15) in the Treatment Isolated Class I Gingival Recession of Defects: A Pilot Study

BACKGROUND This study clinically evaluates the treatment outcome of coronally positioned flap (CPF) associated with anorganic bone mineral/peptide-15 (ABM/P-15) in terms of root coverage and gain in clinical attachment level (CAL) and bone height (BH) in isolated Class I gingival recession (GR) defects. METHODS Fifteen healthy subjects with bilateral and comparable Miller Class I GR defects were selected. The defects were randomly assigned either to the test group (CPF with ABM/P-15) or to the control group (CPF only). RESULTS Six months after surgery, a reduction in GR was observed in the test and control groups (2.20 ± 0.54 and 2.40 ± 0.80 mm, respectively; P <0.001) with no intergroup difference (P = 0.33). Complete root coverage was obtained in 10 and 11 defects in the test and control groups, respectively. In the test group 85.56% ± 21.69% and in the control group 90.00% ± 18.42% of the exposed root was covered. Although not clinically significant, a statistically greater increase in the gingival thickness was observed in the test group (0.03 mm; P = 0.01). CAL gain was significant in both groups (test group, 1.93 ± 0.44 mm; control group, 2.13 ± 1.15 mm; P <0.001) with no intergroup difference (P = 0.42). Intergroup and intragroup differences in width of keratinized tissue and BH were not significant (P ≥0.16). In the test group, a positive correlation was observed between BH at baseline and the reduction in GR (r = 0.56; P = 0.03). CONCLUSIONS In isolated Class I GR defects, CPF associated with ABM/P-15 provided no significant difference in root coverage and CAL gain compared to CPF alone. In the ABM/P-15 group, a greater reduction in GR was associated with higher bone level at baseline.

Evaluation of the effects of buccal-palatal bone width on the incidence and height of the interproximal papilla between adjacent implants in esthetic areas.

BACKGROUND The presence of interproximal papilla depends on the distance between the contact point to the bone crest, as well as the mesio-distal distance between implants or between implants and teeth. The aim of this study is to evaluate the effects of buccal-palatal bone width on the presence of the interproximal papilla between adjacent implants in esthetic areas of the mouth. METHODS The presence or absence of the gingival papilla, distance from the base of the interproximal contact to the tip of the gingival papilla (black space), distance from the base of the interproximal contact to the alveolar crest (vertical distance), alveolar bone width (bone width) between adjacent implants as well as the spacing between the implants (horizontal distance), and soft-tissue biotype were assessed in 29 interimplant areas in the upper incisor, canine, and premolar regions of 18 patients. RESULTS The papilla was always present when vertical distance was ≤5 mm (P ≤0.04) and frequently present when the horizontal distance was ≥4 mm (P = 0.04). The black space was smaller when the vertical distance was ≤5 mm (P ≤0.04) and when the horizontal distance was ≥4 mm (P = 0.76). Bone width and soft-tissue biotype did not influence the incidence of gingival papilla (P ≥0.41) and black space (P ≥0.15). CONCLUSION Within the limits of this study, it can be concluded that bone width and tissue biotype do not have an effect on the incidence and height of papilla between adjacent implants in esthetic areas, and the incidence was greater when vertical distance was ≤5 mm or when horizontal distance was ≥4 mm.

Distribution of mast cells in benign odontogenic tumors.

The aim of this study was to investigate the presence of mast cells in a series of odontogenic tumors. Forty-five cases of odontogenic tumors were investigated using immunohistochemistry for mast cell triptase, and differences between groups were statistically evaluated. Mast cells were present in 96% of odontogenic tumors. Mast cells present in solid ameloblastoma were observed in the tumor stroma surrounding more solid and follicular epithelial islands, with or without squamous metaplasia. The odontogenic mixoma showed few mast cells. In odontogenic tumors with a cystic structure, the mast cells were distributed throughout all areas of the lesions, mainly in keratocystic odontogenic tumor. In addition, the total density of mast cells between all odontogenic tumors showed no significant difference (p > 0.05). A greater mast cells distribution was found in keratocystic odontogenic tumor in relation to adenomatoid odontogenic tumor (p < 0.01), and when the unicystic ameloblastoma and keratocistic odontogenic tumor were compared to the odontogenic myxoma (p < 0.05). Syndrome keratocystic odontogenic tumor showed a higher mean of mast cells when compared with the other tumors of the sample. Mast cells values presented by syndrome keratocystic odontogenic tumor were significantly greater than those of the sporadic keratocystic odontogenic tumor that were not associated with the syndrome (p = 0.03). Mast cells are probably one of the major components of the stromal scaffold in odontogenic tumors. We found significant differences of mast cells between syndrome nonsyndrome keratocystic odontogenic tumors, although their distribution did not seem to have any influence on the biologic behavior of benign odontogenic tumors.