60 research outputs found
Primary enamel permeability: a SEM evaluation in vivo.
No full textAIM:
The aim of this study was to evaluate in vivo the occurrence of outward fluid flow on primary tooth sound enamel surface.
MATERIALS AND METHODS:
Sixty primary upper canines from preadolescent patients (mean age 8.0±1.9) and 24 retained primary upper canines from adult subjects (mean age 35.0±1.8) were analysed. The enamel surface was gently polished and air dried for 10 s. An impression was immediately obtained by vinyl polyxiloxane. Replicas were then obtained by polyether impression material, gold coated and inspected under SEM. The hydrophobic vinyl polyxiloxane material enabled to obtain in situ a morphological image of the presence of droplets, most likely resulting from outward fluids flow through outer enamel. For each sample three different representative areas of 5μ2 in the cervical, medium and incisal third were examined and droplets presence values was recorded. All data were analysed by by Fisher's exact test.
RESULTS:
Primary enamel showed a substantial permeability expressed as droplets discharge on its surface. Droplets distribution covered, without any specific localisation, the entire enamel surface in all the samples. No signs of post-eruptive maturation with changes in droplets distribution were observed in samples from adult subjects. No statistically significant differences (P = 0.955) were noted in the percentage distribution of enamel area covered with droplets among the two group studied.
CONCLUSION:
SEM evaluation of droplets distribution on enamel surface indicated a substantial enamel permeability in primary teeth, accordingly with histological features, without changes during aging. A relationship between enamel permeability, caries susceptibility and bonding procedures effectiveness could be hypothesised
Coronoid hyperplasia. A case report.
No full textCoronoid hyperplasia is a rare condition which is macroscopically characterized by an increase in the dimensions of the coronoid process resulting from an abnormal bony elongation of histologically normal bone. Unilateral cases are more frequent than bilateral ones and can recognize a number of etiological factors, such as exostoses, osteochondroma, traumatic events, inflammatory reactions, neoplasia and manifestations secondary to other pathologies. Etiopathogenesis of bilateral forms has not yet been clarified: in the literature hints to both developmental and endocrine abnormalities are present, and a familiar pattern of inheritance has been evidenced. The poor specificity of signs and symptoms associated with coronoid hyperplasia, which are similar to those of other more frequent forms of temporomandibular disorders, present some problems of differential diagnosis. An accurate assessment must be based on a clinical and anamnestical approach aiming at the identification of pathognomonic clinical symptoms. Considering its limits (such as the possible presence of artefacts and image distortions), orthopantomography has a poor diagnostic usefulness. In this case, magnetic resonance (MR) allowed to evaluate disk-condyle relationship, but it could be also useful to evaluate post-operative complications. In the case of coronoid hyperplasia, the computed tomography (CT) is fundamental for a correct differential diagnosis. CT also allows surgical planning due to its accuracy to detect coronoid process volume and morphology. The present case report is an example of the need for a correct differential diagnosis between the different types of temporomandibular disorders, and it also lends support to the importance of requesting modern imaging techniques during the diagnostic process of the rare or complex cases
In vitro comparison of root surface treatment effect between root scaling with ultrasonic inserts and gracey curette and polishing with different cleaning pastes
No full textThe aim of this study was the morphological evaluation of root surfaces subjected to manual (curette) and ultrasonic (conventional and diamond tips) scaling. The surface was then polished with a rubber cup and three medium-sized pastes. Ninety teeth were randomly divided into three groups of 30 and subjected to three different root instrumentation: (1) manual instrumentation with a Gracey® curette; (2) ultrasonic instrumentation with a standard steel tip (Universal Perio S-SERIES: USU, Hu-Friedy, Chicago, IL, USA) at a power equal to 50%; and (3) with a diamond tip (Punta Piezo Serie E Scaling, Hu-Friedy, Chicago, IL, USA) at a power of 20%. Each group of the instrumented teeth was then divided in three subgroups of 10 and subjected to 30 s of rubber polishing with three different polishing pastes with medium grain sizes in single-dose cups: (1) Ultrapro Tx cool mint medium®; (2) Stomyprox media®; and (3) Nupro medium orange®. Polyether root surface replicas were then taken from all 90 samples and analyzed by SEM to evaluate surface morphology after scaling and polishing procedures. All scaling techniques caused an alteration of the root surface without statistically significant difference, whereas polishing resulted in maintenance or improvement of the surface texture
In vivo effects of two in-office vital tooth bleaching systems on enamel permeability
No full textTooth bleaching is a common treatment for the amelioration of the aesthetic of discoloured teeth. In this context, there are two common approaches that employ concentrated solutions (30–40 wt.%) of either hydrogen peroxide or carbamide peroxide as bleaching agents. However, there is an ongoing debate on the possible adverse effects of these different treatments on tooth health, such as variation of the enamel structure, surface morphology, and chemistry, which also affect tooth sensitivity. In the present work, a study on the effect of the two bleaching agents, a 35 wt.% solution of hydrogen peroxide and a 30 wt.% solution of carbamide peroxide, on the permeability and surface morphology of enamel is reported. The investigation was carried out on replicas of incisors obtained after different treatment times and for several patients, employing scanning electron microscopy to study the morphological features of the treated teeth. The significance of the analytical study was corroborated by a statistical analysis of the results. The collected data suggest that hydrogen peroxide treatment increases the enamel permeability, and this could be related with tooth sensitivity, whereas the carbamide peroxide solution increases the formation of precipitates on the tooth enamel
The influence of smear layer in lateral channels filling.
No full textThis in vitro study evaluated the ability of a warm gutta-percha obturation system Thermafil to fill lateral channels in presence/absence of smear layer. Forty single-rooted extracted human teeth were randomly divided into two groups for which different irrigation regimens were used: group A, 5 ml of 5% NaOCl + 2.5 ml of 3.6% H(2)O(2); group B, 5 ml of 5% NaOCl 5% + 2.5 ml of 17% ethylenediamine tetraacetic acid. A conventional crown-down preparation technique was employed. Obturation was performed using epoxy resin-based cement (AH Plus) and a warm gutta-percha plastic carrier system (Thermafil). Specimens were cleared in methyl salicylate and analyzed under a stereomicroscope to evaluate the number, length, and diameter of lateral channels. Lateral channels were identified in both groups at medium and apical thirds. Additional samples were prepared for scanning electron microscopy inspection to confirm the presence of smear layer in group A, and the absence of smear layer in group B. All lateral channels resulted filled in both groups. No statistically significant differences regarding number, length, and diameter were observed between the two groups. Smear layer did not prevent the sealing of lateral channels
Prevalenza delle diverse forme di Disordini Temporomandibolari secondo i criteri RDC/TMD.
No full textRelazione tra sintomatologia otoiatrica e disordini temporomandibolari: attuali orientamenti.
No full text
Segni e sintomi di disfunzione stomatognatica in corso di sindrome fibromialgica. Studio descrittivo su 93 pazienti
No full textDevelopment of A Nano-Apatite Based Composite Sealer for Endodontic Root Canal Filling
No full textRecently, endodontic sealers based on injectable bioactive materials were proposed to improve the filling of anatomical irregularities during root canal obturation. In this context, this preliminary work investigated the possibility of realizing a new calcium phosphate-based composite sealer for root canal filling with an optimized composition on setting kinetics and dentin tubules occlusion. Several calcium phosphate/liquid phase mixtures were initially evaluated for their workability, finding two suitable formulations. Both of them contained 66 wt.% of a nano-apatite-based cement (solid powdered phase). The liquid phase (34 wt.%) comprised 13.6% propanediol and 20.4% PEG 1000 (formulation 1), and formulation 2 comprised 27.2% glycerin and 6.8% PEG 200 (formulation 2). Then, these formulations were tested by means of permeability measurements and observation by scanning electron microscopy of treated model dentin samples. Both formulations succeeded in occluding dentinal tubules: the first one was able to create a full-bodied layer on dentin surface and, moreover, to resist, at least to a large extent, against citric acid attack. The second one showed a lower effectiveness after citric acid exposure. The composite compound that better satisfied the overall required characteristics of use, workability and sealing capacity was formulation 1
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