Vertical Discrepancy in Height of Morse Cone Abutments Submitted to Different Torque Forces.

The present study aimed to evaluate the influence of manual torque (10 Ncm) versus clinical torque (30 Ncm), which is recommended by the manufacturer, on the total length of morse cone implant abutments. Twenty specimens were prepared and distributed into two groups: group 1 with ten analogs for morse cone type implant, and group 2 with ten morse type implants, size 4.3 × 15 cm. In each group, the distance between the implant platform to the top of the prosthetic abutment (abutment height) was measured and subjected to a torque of 10 Ncm. Then, the 30 Ncm torque was applied to the same abutment, and abutment height was measured. The distance between the top of the abutment and the implant/analog base was measured. In order to verify the clinical reproducibility of the experiment, comparisons between the abutment height of the analog at 10 Ncm and the implant at 30 Ncm were performed, showing a greater discrepancy in torque for the 10 Ncm analog (p < 0.05). In order to verify if the change in the laboratory protocol from 10 to 30 Ncm could minimize the differences in the height of the prosthetic abutments, the abutment height in groups 1 and 2 was compared with 30 Ncm, and no significant difference was observed (p > 0.05). The data indicated that the manual torque and the torque recommended by the manufacturer influence the total length of the prosthetic abutments of morse cone implants.

Analysis of Active Oral Tactile Sensitivity in Individuals with Complete Natural Dentition.

AIM: To evaluate the active tactile sensitivity in individuals with complete natural dentition, determining the smallest thickness detected by the participants, and clarifying if there is a difference between the thicknesses analyzed. MATERIALS AND METHODS: Active tactile sensitivity was evaluated in 40 research participants. Inclusion criteria included participants with complete natural dentition, without active or history of periodontal disease, absence of temporomandibular disorders, bruxism, and restorations in the evaluated area. Exclusion criteria included age below 18 years. The active tactile perception threshold was evaluated by using carbon sheets of different thicknesses (0, 12, 24, 40, 80, 100, and 200 µm), which were inserted in the participants' premolars, bilaterally. The carbon sheet was inserted so as not to come into contact with the oral soft tissues. Subsequently, the participant occluded and was asked about the perception of the intraocclusal object 20 times in each occlusal contact. The collected data were tabulated considering the amount of positive and negative responses for each carbon thickness. Values of p < 0.05 were considered significant. RESULTS: The results showed that there was linearity in perception, on both sides, besides, the natural dentition was able to perceive difference in thickness from 12 µm. CONCLUSION: We conclude that the 12 µm thickness is noticeable in occlusion and can be differentiated from other thicknesses in natural dentition and that there is no difference between the tactile sensitivity of the right and left sides. CLINICAL SIGNIFICANCE: A better understanding of active oral tactile sensitivity will contribute to numerous clinical applications in dentistry, including occlusal adjustment in dental rehabilitation, dental implants prosthesis design, and survival of prosthetic rehabilitation.

Dental genetics in Brazil: Where we are.

Dentistry constitutes the basic nucleus of professionals of higher level of health in Brazil with one of the largest concentrations of dentists per capita in the world. However, the genetic in dentistry in Brazil is explored, basically, in research field. Future actions need to be performed in order to deep the whole knowledge about diagnosis and treatment of diseases with genetic basis in dentistry, in Brazil.

Aquaporin 5 Interacts with Fluoride and Possibly Protects against Caries.

Aquaporins (AQP) are water channel proteins and the genes coding for AQP2, AQP5, and AQP6 are clustered in 12q13. Since AQP5 is expressed in serous acinar cells of salivary glands, we investigated its involvement in caries. DNA samples from 1,383 individuals from six groups were studied. Genotypes of eight single nucleotide polymorphisms covering the aquaporin locus were tested for association with caries experience. Interaction with genes involved in enamel formation was tested. The association between enamel microhardness at baseline, after creation of artificial caries lesion, and after exposure to fluoride and the genetic markers in AQP5 was tested. Finally, AQP5 expression in human whole saliva, after exposure to fluoride in a mammary gland cell line, which is known to express AQP5, and in Wistar rats was also verified. Nominal associations were found between caries experience and markers in the AQP5 locus. Since these associations suggested that AQP5 may be inhibited by levels of fluoride in the drinking water that cause fluorosis, we showed that fluoride levels above optimal levels change AQP5 expression in humans, cell lines, and rats. We have shown that AQP5 is involved in the pathogenesis of caries and likely interacts with fluoride.

Different contribution of BRINP3 gene in chronic periodontitis and peri-implantitis: a cross-sectional study.

BACKGROUND: Peri-implantitis is a chronic inflammation, resulting in loss of supporting bone around implants. Chronic periodontitis is a risk indicator for implant failure. Both diseases have a common etiology regarding inflammatory destructive response. BRINP3 gene is associated with aggressive periodontitis. However, is still unclear if chronic periodontitis and peri-implantitis have the same genetic background. The aim of this work was to investigate the association between BRINP3 genetic variation (rs1342913 and rs1935881) and expression and susceptibility to both diseases. METHODS: Periodontal and peri-implant examinations were performed in 215 subjects, divided into: healthy (without chronic periodontitis and peri-implantitis, n = 93); diseased (with chronic periodontitis and peri-implantitis, n = 52); chronic periodontitis only (n = 36), and peri-implantitis only (n = 34). A replication sample of 92 subjects who lost implants and 185 subjects successfully treated with implants were tested. DNA was extracted from buccal cells. Two genetic markers of BRINP3 (rs1342913 and rs1935881) were genotyped using TaqMan chemistry. Chi-square (p < 0.05) compared genotype and allele frequency between groups. A subset of subjects (n = 31) had gingival biopsies harvested. The BRINP3 mRNA levels were studied by CT method (2(ΔΔCT)). Mann-Whitney test correlated the levels of BRINP3 in each group (p < 0.05). RESULTS: Statistically significant association between BRINP3 rs1342913 and peri-implantitis was found in both studied groups (p = 0.04). The levels of BRINP3 mRNA were significantly higher in diseased subjects compared to healthy individuals (p = 0.01). CONCLUSION: This study provides evidence that the BRINP3 polymorphic variant rs1342913 and low level of BRINP3 expression are associated with peri-implantitis, independently from the presence of chronic periodontitis.

The effect of autologous concentrated bone-marrow grafting on the healing of femoral shaft non-unions after locked intramedullary nailing.

The aim of this study was to assess the union rates in a series of patients with failed femoral shaft aseptic non-union who were treated with percutaneous concentrated autologous bone marrow grafting. Bone marrow harvesting and cell injection were performed under general anaesthesia in a single surgical procedure. Radiographic union was diagnosed in fractures with a score ≥ 10 according to the radiographic union scale in tibial fractures (RUST) and confirmed by clinical examination. Eight out of 16 patients progressed to consolidation (RUST score ≥ 10). Radiographic evidence of fracture union was observed at an average of 4.75 ± 1.75 months (range 3 to 8 months). All eight patients who did not progress to union within 12 months following the cell grafting procedure had a RUST score ≤ 10 (range 4 to 9). There were no differences in age, number of previous surgeries, duration of nonunion and preoperative RUST score between the patients that developed solid union and those with failed consolidation. However, a relationship between the number of osteoprogenitors injected and the rate of union was noted, 20.2 ± 8.6 × 10(8) versus 9.8 ± 4.3 × 10(8), p<0.005, between the patients with and without union, respectively. The efficacy of percutaneous autologous concentrated bone marrow grafting seems to be related to the number of osteoprogenitors available in the aspirates. Optimisation of the aspiration technique and concentration process is of paramount importance to increase the incidence of a successful outcome.

Genome wide association scan for chronic periodontitis implicates novel locus.

BACKGROUND: There is evidence for a genetic contribution to chronic periodontitis. In this study, we conducted a genome wide association study among 866 participants of the University of Pittsburgh Dental Registry and DNA Repository, whose periodontal diagnosis ranged from healthy (N = 767) to severe chronic periodontitis (N = 99). METHODS: Genotypingi of over half-million single nucleotide polymorphisms was determined. Analyses were done twice, first in the complete dataset of all ethnicities, and second including only samples defined as self-reported Whites. From the top 100 results, twenty single nucleotide polymorphisms had consistent results in both analyses (borderline p-values ranging from 1E-05 to 1E-6) and were selected to be tested in two independent datasets derived from 1,460 individuals from Porto Alegre, and 359 from Rio de Janeiro, Brazil. Meta-analyses of the Single nucleotide polymorphisms showing a trend for association in the independent dataset were performed. RESULTS: The rs1477403 marker located on 16q22.3 showed suggestive association in the discovery phase and in the Porto Alegre dataset (p = 0.05). The meta-analysis suggested the less common allele decreases the risk of chronic periodontitis. CONCLUSIONS: Our data offer a clear hypothesis to be independently tested regarding the contribution of the 16q22.3 locus to chronic periodontitis.

Immediate dental implant failure associated with nasopalatine duct cyst.

This case report presents an analysis of the clinical, radiographic, and histological features of a peri-implant lesion around an implant placed immediately after extraction of a tooth with a periapical lesion. A 52-year-old man received an immediate implant (3.75 x 11.5 mm2) placed in the anterior region of the maxilla. Three years after implant placement, the patient presented with swelling in the anterior portion of the maxilla. Radiographic examination showed a well-circumscribed radiolucency around the implant. The implant and the lesion were removed and fixed in 10% buffered formalin and processed. Histological analysis showed 3 types of epithelium: respiratory, cuboidal, and non-keratinized stratified squamous. In the cyst wall peripheral nerves, arteries, veins, and chronic inflammation were present. The diagnosis was nasopalatine duct cyst. We concluded that the nasopalatine duct cyst can develop in association with dental implants. Clinically, the lesion is similar to the classical nasopalatine duct cyst. Histological analysis should be mandatory in all cases of peri-implant lesions and in all dental periapical lesions before immediate implant placement.