Buccal bone dimensions and aesthetic outcome at maxillary incisors replaced by conventional dental implants. A case series with a 5-year follow-up.

In the aesthetic field, successful replacement of a tooth with a dental implant requires blend and harmony within the existing dentition. The influence of the dimension of buccal bone at implant sites on aesthetic outcomes and the relation between buccal bone horizontal and vertical dimensions are unclear. The aim of the present study is to investigate the correlation between buccal bone thickness, buccal bone level and aesthetic outcome in conventionally placed implants ­ placed five or more years previously ­ supporting single maxillary incisors. Eight subjects with 8 implants and with periapical and parallel profile X-rays were clinically examined to assess the "Pink Aesthetic Score" (PES). Buccal bone level and thickness, together with the interproximal bone level, were measured. Implant survival was 100%. The mean time of implants function was 89.3 months (standard deviation 43, range 61-145). The mean PES value was 9.4. The mean interproximal bone level was located 1.3 mm apically to the implant abutment junction, while the corresponding buccal value was 1.6 mm. Buccal bone was mostly absent at the implant abutment junction; 2 and 4 mm apically respect to the junction the thickness was on average 0.44 and 0.89 mm, respectively. The dimension of buccal bone level was correlated to the buccal bone thickness at 2mm-level, to the interproximal bone level and to the soft tissue contour score. Conventional implant placement in pristine bone might lead to satisfactory long-term aesthetic results. The level of the facial mucosa and appearance of the alveolar process might emerge as critical aspects.

Powder-based 3D printing for bone tissue engineering.

Bone tissue engineered 3-D constructs customized to patient-specific needs are emerging as attractive biomimetic scaffolds to enhance bone cell and tissue growth and differentiation. The article outlines the features of the most common additive manufacturing technologies (3D printing, stereolithography, fused deposition modeling, and selective laser sintering) used to fabricate bone tissue engineering scaffolds. It concentrates, in particular, on the current state of knowledge concerning powder-based 3D printing, including a description of the properties of powders and binder solutions, the critical phases of scaffold manufacturing, and its applications in bone tissue engineering. Clinical aspects and future applications are also discussed.

Crotalphine desensitizes TRPA1 ion channels to alleviate inflammatory hyperalgesia

Crotalphine is a structural analogue to a novel analgesic peptide that was first identified in the crude venom from the South American rattlesnake Crotalus durissus terrificus. Although crotalphine's analgesic effect is well established, its direct mechanism of action remains unresolved. The aim of the present study was to investigate the effect of crotalphine on ion channels in peripheral pain pathways. We found that picomolar concentrations of crotalphine selectively activate heterologously expressed and native TRPA1 ion channels. TRPA1 activation by crotalphine required intact N-terminal cysteine residues and was followed by strong and long-lasting desensitization of the channel. Homologous desensitization of recombinant TRPA1 and heterologous desensitization in cultured dorsal root ganglia neurons was observed. Likewise, crotalphine acted on peptidergic TRPA1-expressing nerve endings ex vivo as demonstrated by suppression of calcitonin gene-related peptide release from the trachea and in vivo by inhibition of chemically induced and inflammatory hypersensitivity in mice. The crotalphine-mediated desensitizing effect was abolished by the TRPA1 blocker HC030031 and absent in TRPA1-deficient mice. Taken together, these results suggest that crotalphine is the first peptide to mediate antinociception selectively and at subnanomolar concentrations by targeting TRPA1 ion channels

Isolation and characterization of microsatellite loci for Bixa orellana, an important source of natural dyes.

Annatto (Bixa orellana) is a plant native from the American continental tropical zone. The seeds are used to produce a carotenoid-based yellow to orange food coloring. Microsatellite markers were developed for the Brazilian native species Bixa orellana to describe its genetic diversity and structure as well as to support conservation studies. Twenty-five microsatellite loci were isolated and characterized using an enriched genomic library. Ten loci were polymorphic in the 50 accessions sampled in this study, while 15 were considered monomorphic. The mean number of alleles per locus was 3.8, ranging from 2 to 6 alleles per locus. Mean values for the observed and expected heterozygosities were 0.541 (ranging from 0 to 0.658) and 0.639 (ranging from 0.422 to 0.787), respectively. All markers described in this study will be useful in further studies evaluating the genetic diversity, population dynamics, and conservation genetics of Bixa orellana.

Genetic structure and diversity in the Dioscorea cayenensis/D. rotundata complex revealed by morphological and isozyme markers.

Of the 600 known yam species, only 10 are utilized as food, and the Dioscorea cayenensis/D. rotundata species complex is among the most cultivated. In Brazil, these species are commercially cultivated in the northeast region and are cultivated in the south and southeast regions as subsistence crops by traditional agriculturists. This study aimed to evaluate the genetic diversity of 21 local varieties of D. cayenensis and 2 D. rotundata accessions using 7 isozymic loci and 24 morphological markers, and to investigate the diversity distribution in different levels of organization, such as swidden fields and communities of Vale do Ribeira. Cluster analyses for both the isozymic and morphological data separated the 2 D. rotundata accessions from the D. cayenensis accessions from Vale do Ribeira. The analysis with morphological characteristics showed the presence of 2 subgroups (Iguape and Cananéia) within group I, which included all of the local varieties from Vale do Ribeira; this result may indicate the influence of the cultural units on the morphological variation. Molecular analysis of variance indicated that most of the isozymic variability was concentrated among swiddens within communities (42.5%) and within communities (40.3%). Most of the morphological variability was also concentrated among swidden fields within communities (44.8%). The correlation between geographic and genetic distances indicated that neither morphological (r = 0.17) nor isozymic diversity (r = -0.15) is structured in space. Thus, the traditional agriculturists of Vale do Ribeira maintain and manage a great diversity of D. cayenensis varieties in their communities.

Efficacy of an anesthetic gel in the reduction of pain during impression making.

INTRODUCTION: Gingival tissue displacement can be an uncomfortable procedure, often performed without injectable local anesthesia. The present study evaluated the efficacy of an anesthetic gel in reducing pain during this procedure. MATERIAL AND METHODS: Thirty patients undergoing definitive dental impression, for fabricating full-coverage restorations, were evaluated for pain perception on displacement of the surrounding gingival tissues. All the participants were randomly divided into two groups. Five minutes before the insertion of the displacement cord, the anesthetic gel, a mixture of 5% lidocaine and 5% prilocaine, was applied in the sulcus of test group patients. Each patient was asked to complete the Visual Analogue Scale (VAS) and the Verbal Rating Scale (VRS). RESULTS: In the two scales considered, test group patients showed a statistically significant pain reduction (VAS p=0.0002, VRS p=0.01054) compared to control group patients. CONCLUSIONS: Within the limitations of this study, a clinically significant efficacy of the anesthetic gel was noticed during gingival displacement procedures.

Measurement of the velocity of neutrinos from the CNGS beam with the large volume detector.

We report the measurement of the time of flight of ∼17 GeV ν(µ) on the CNGS baseline (732 km) with the Large Volume Detector (LVD) at the Gran Sasso Laboratory. The CERN-SPS accelerator has been operated from May 10th to May 24th 2012, with a tightly bunched-beam structure to allow the velocity of neutrinos to be accurately measured on an event-by-event basis. LVD has detected 48 neutrino events, associated with the beam, with a high absolute time accuracy. These events allow us to establish the following limit on the difference between the neutrino speed and the light velocity: -3.8 × 10(-6) < (v(ν)-c)/c < 3.1 × 10(-6) (at 99% C.L.). This value is an order of magnitude lower than previous direct measurements.

Comparison by means of bispectral index score, between anxiolysis induced by diazepam and sedation induced by midazolam.

AIM: Bispectral Index Score (BIS) is an objective tool to assess sedation depth. Benzodiazepines have different pharmacological profiles and diazepam may be safer than midazolam in this setting. The aim of this study was to compare BIS values observed during anxiolysis after diazepam versus sedation after midazolam. METHODS: Thirty-six patients were randomly assigned to 3 groups: group 1 was treated with i.v. diazepam, groups 2 and 3 with iv midazolam 1 and 3 mg, respectively. Sedation was monitored clinically and by means of BIS. BIS values were evaluated as area under the curve (AUC) and compared by variance analysis. The statistical comparison of other data was performed by variance analysis or, alternatively, the χ2 according to Yates. The statistical significance was indicated by P values <0.05. RESULTS: AUC values were significantly lower after midazolam when compared to AUC values registered in diazepam treated patients; 22.6% of the group 3 patients showed BIS values <80, versus 0.4% of group 1 patients. CONCLUSION: Diazepam has a safer profile, with BIS values and clinical conditions according to the definition of minimal and/or moderate sedation. Diazepam represents the safer drug for anxiety management in dentistry, because regularly produces a state of sedation during which verbal contact with the patient is maintained and carry a margin of safety wide enough to render loss of consciousness unlikely.

Reliability and reproducibility of linear mandible measurements with the use of a cone-beam computed tomography and two object inclinations.

OBJECTIVE: The aim of this study was to assess the influence of inclination of the object on the reliability and reproducibility of linear measurements of anatomic structures of the mandible on images obtained using cone-beam CT (CBCT). METHODS: Ten linear dimensions between anatomical landmarks were measured in a dry mandible. The measurements were performed with a manual calliper three times by three observers. The mandible was scanned with Planmeca Promax 3D cone-beam CT (Planmeca Oy, Helsinki, Finland) with the base of the mandible parallel as well as tilted 45° to the horizontal plane. Computer measurements of the linear dimension were performed by three observers. The radiographic measurements were performed four times for each experimental setting. A total of 240 measurements were performed. Reproducibility was evaluated through comparison of standard deviation (SD) and estimation of intraclass correlation coefficient (ICC). The error was estimated as the absolute difference between the radiographic measurements and the mean manual calliper measurements. RESULTS: The mean SD for the radiographic measurements was 0.36 mm for the horizontally positioned mandible and 0.48 mm for the inclined mandible. The ICC between examiners was 0.996 mm, between sessions was 0.990 mm and between CBCT measurements and calliper was 0.992 mm. The overall absolute mean measurement error was 0.40 mm (SD 0.39 mm). The percentage of errors that exceeded 1 mm was 6.7%. CONCLUSION: The results revealed high reliability of measurements performed on CBCT images independently from object position, examiner's experience and high reproducibility in repeated measurements settings.

Tooth fragment reattachment through the use of a nanofilled composite resin.

AIM: The purpose of this study is to evaluate resistance to fracture with static tests of dental fragments reattached through the use of different light-curing composite resins. For this purpose 40 bovine inferior incisors were utilised, which were randomised into 4 groups; one control group and 3 experimental groups. MATERIALS AND METHODS: All teeth of the 3 experimental groups were sawed at 3 mm from the incisal margin, and the respective fragments were then reattached utilizing different composite resins: in group 2_EI the hybrid composite Tetric EvoCeram (Ivoclar Vivadent AG) was used, in group 3_ZI the hybrid composite FiltekTM Z250 (3M ESPE) was used, and in group 4_SN the nanofilled composite FiltekTM Supreme (3M ESPE) was used. After reattachment, on each tooth were performed a chamfer on the buccal surface and an overcontour on the lingual surface along the fracture line, which were then filled with the composite resin corresponding to the respective group. Finally, all teeth were embedded in plaster blocks, and a force was applied on the buccal surface. RESULTS: All teeth in groups 2, 3, and 4 showed a significant loss of resistance to fracture compared to the teeth of the control group (P<0.0001). Resistance to fracture of the teeth belonging to groups 2_EI and 3_ZI was 37.35% and 47.35% of that of intact teeth respectively; in group 4_SN resistance to fracture reached 60.05%. Teeth of group 2 exhibited values of resistance to fracture statistically significant from those of group 4 (P=0.024), but no difference was found between group 2 and group 3 (P=0.298). The difference in resistance between group 3 and group 4 was not statistically significant (P=0.199). CONCLUSION: Static test showed that reattachment of coronal fragments do not restore resistance to fracture to the value of intact teeth. Resistance to fracture in in vitro studies is influenced by the type of composite resin utilised.

Solitary neurofibroma of the palate. A case report.

The neurofibroma is a benign tumor of neuronal origin not frequently located in the oral cavity. The possible association of this neoplasia with systemic pathologies, such as Von Recklinghausen's disease and multiple endocrine neoplasia, makes its diagnosis fundamental. The diagnosis is, in most cases, quite complex, because of the neurofibroma's strong similarities with a great number of benign neoformations of the connective tissue, of the epithelium, and of the bone. The histology represents, therefore, the fundamental diagnostic criterion, in particular, through the use of appropriate immunohistochemical analysis. This articles presents the case of a solitary neurofibroma, subtype I (common Schwann cell type), detected on the left-hand side of the posterior region of the palate in a 56-year-old woman, which presented itself as an otherwise non-symptomatic ulcerated mass. After a careful anamnesis, an incisional biopsy was performed in order to establish the histological nature of the neoformation. The immunohistochemical test, which resulted positive for S-100 and negative for the epithelial membrane antigen and keratin, allowed the diagnosis of a presumably benign lesion deriving from a neural differentiation. The surgical excision of the entire mass was accompanied by the extraction of the upper left-hand second molar, which was attached to the mass through its palatal root.

Antiinflammatory effects of etoricoxib alone and combined with NSAIDs in LPS-induced reactive arthritis.

OBJECTIVE: Nonsteroidal anti-inflammatory drugs constitute the primary therapeutic approach in reactive arthritis. Here, we compared etoricoxib, a specific COX-2 inhibitor, with other cyclooxygenase inhibitors on articular incapacitation, edema, leukocyte migration, and gastric damage, in a model of LPS-induced reactive arthritis in rats. METHODS: E. coli Lipopolysaccharide was injected into a carrageenan-primed knee-joint of rats. The effects of etoricoxib, piroxicam, indomethacin, as well the combination of etoricoxib either with piroxicam or indomethacin, were evaluated on articular incapacitation and edema. Afterwards, the synovial leukocyte ontent and the stomach bleeding points were counted. RESULTS: Etoricoxib, piroxicam, and indomethacin dose-dependently inhibited incapacitation and edema. However, only etoricoxib inhibited both mononuclear and polymorphonuclear leukocyte migration. Piroxicam inhibited only mononuclear migration, while indomethacin even increased polymorphonuclear content in inflamed synovia. Associating etoricoxib with either subeffective doses of piroxicam or indomethacin did not enhance the hyponociceptive or the antiedematogenic effect, but prevented the anti-leukocyte migration effect and increased gastric damage. CONCLUSION: The present results suggest that the selective COX-2 inhibitor etoricoxib could be a better option than non-selective COX inhibitors, since it presented a potent inhibitory effect on the clinical signals and also a potent inhibition on cell migration.

Extraoral endodontic treatment, odontotomy and intentional replantation of a double maxillary lateral permanent incisor: case report and 6-year follow-up.

AIM: To describe combined endodontic, surgical and orthodontic treatment of a maxillary lateral incisor fused with a supernumerary. SUMMARY: Double tooth is a dental irregularity consequent to fusion of two or more teeth or dental gemination. The teeth most commonly involved are deciduous, but in 0.1% of cases permanent teeth are affected, in which case aesthetic, functional and periodontal problems can result. This paper reports a clinical case of a double tooth in the position of the maxillary right lateral permanent incisor. Combined orthodontic, endodontic and surgical treatment (intentional replantation) allowed the tooth to be retained without periodontal compromise and with a positive orthodontic result both immediately and 6 years following intervention. *A conservative approach that addresses periodontal, pulpal and tooth tissues, can result in the retention of a double tooth. *Maintenance of the root and alveolar bone in young adults at least until full skeletal maturation should be the main treatment objective.

Comparative evaluation of different techniques of surface preparation for occlusal sealing.

AIM: Aim of this experiment is the efficacy evaluation of three different types of surface preparation techniques by microleakage assessment of two different sealing materials. MATERIALS AND METHODS: Sixty teeth were used for the experiment: half were treated with Admira seal (Voco) and the remaining half with Delton FS+ (Dentsply). Each group was then divided into three subgroups, which underwent three different preparation techniques before sealant placement: mechanical brushing, air abrasion and Intensive bur FG 40D4, respectively. After immersion of the specimens in methylene blue solution, the degree of microleakage was assessed by mean of optic microscope. RESULTS: Results show no microleakage in samples treated with air abrasion, followed by the samples treated with mechanical brushing. The teeth prepared by bur treatment before sealant application show a significant number and degree of marginal infiltration. CONCLUSION: It can be concluded that air abrasion technique is able to guarantee a reliable seal of occlusal surfaces.

Determination of genotoxicity of classical swine fever vaccine in vitro by cytogenetic and comet tests.

Chromosome damage in lymphocyte cultures induced by live virus vaccine against classical swine fever (CSF) has been observed in previous studies. In vivo cytogenetic tests were made with several doses of vaccines used in Argentina to control the disease. These studies have shown that genotoxic effects increased with dose. In the present study, two different in vitro assays were performed by recording the frequency of cells with chromosome alterations and by assessing the ability of the vaccine to damage DNA, using the single cell gel microelectrophoretic assay (comet test). Frequencies of cells with chromosomal alterations increased significantly when compared with controls and were dose (microl/ml) dependent: 0 = 1.23, 5 = 2.29, 10 = 5.42 and 20 = 11.71%. In the comet assay the variables measured, tail length (TL) and tail moment (TM), also increased. For control cultures TL was 2.32 microm, whereas with concentrations of 20 and 100 microl/ml TL were 12.47 and 42.3 microm, respectively. TM of control cultures was 0.18, whereas with vaccine concentrations of 20 and 100 microl/ml TM were 5.52 and 24.52, respectively. Comet frequency distributions differed significantly among treatments. These results agree with previous in vivo observations. Regarding CSF pathogeny, our results support a direct effect of CSF vaccinal virus on lymphocyte DNA. Genotoxicity of CSF vaccine was corroborated in vitro at the cytogenetic and molecular levels.