This in vitro study evaluated the relationship between removal force and the thickness of three orthodontic adhesives, namely, light- and chemical-cured resin cements and a resin-modified glass ionomer cement. The thickness of each adhesive was 50, 100, 150, or 200 µm, and all adhesives were bonded on bovine incisors. Removal force was measured before (TC-0) and after 1,000 thermal cycles (TC-1000), and values were compared. At TC-0, the removal strengths for adhesive thicknesses of 50 and 100 µm were significantly lower than those for thicknesses of 150 and 200 µm (P < 0.05). At TC-1000, removal strengths for adhesive thicknesses of 50 and 100 µm were also significantly lower than those for 150 and 200 µm. Superbond Orthomite specimens showed a significant difference in removal strength between TC-0 and TC-1000 (P < 0.05) at all thicknesses. There was no significant difference in the distribution of adhesive remnant index scores at any thickness. These findings indicate that decreasing the thickness of applied orthodontic adhesive reduces the removal strength required. (J Oral Sci 56, 185-190, 2014)
The aim of this study was to evaluate the radioprotective and reparative effects of compounds based on aloe vera, zinc, and copper against salivary gland dysfunction in Wistar rats. A total of 150 Wistar rats were randomly divided into 12 groups, in which the animals received aloe vera and/or zinc and copper. In eight of these groups the animals were also subjected to irradiation before or after administration of the substances. After 27 days, sialometry tests were performed. Data were analyzed using ANOVA and the Tukey test (P < 0.05). Rats that had been administered aloe vera before or after irradiation showed a significantly higher salivary flow rate than rats that had been simply irradiated. When both substances were administered, a statistically significant difference in the salivary flow rate was observed in comparison with the irradiation alone group seven days after irradiation. The present results suggest that aloe vera exerts positive protective and reparative effects, and can be considered a potential radioprotective substance. (J Oral Sci 56, 191-194, 2014)
Ca(OH)2 aqueous slurry is widely used as an inter-appointment antimicrobial dressing in root canal treatment. The aim of this study was to quantify the particle size and shape of commercialgrade UltraCal XS (UC) and to compare it with that of research-grade Ca(OH)2 (RG) using a flow particle image analyzer (FPIA). The morphology and penetration inside the dentin tubules of the UC and RG particles were examined using a scanning electron microscope (SEM). UC and RG (10 mg) were mixed with 15 mL of alcohol, and were sonicated. Five milliliters of the dispersion was subjected to FPIA, and particle length, width, perimeter and aspect ratio were analyzed. In addition, UC paste and RG aqueous slurry were agitated on dentin discs and were prepared for SEM examination. There were significant differences between UC and RG with regard to the frequency of different length groups (P < 0.0001). UC contained smaller particles than RG (P < 0.0001). Under SEM, the agitated UC and RG particles occluded the opening of dentin tubules and penetrated inside the dentin tubules. The size of UC particles is smaller than those of RG. Both UC and RG particles were able to penetrate into open dentin tubules. (J Oral Sci 56, 195-199, 2014)
We compared the surface free energies and dentin bond strengths of two-step self-etch systems with and without an oxygen-inhibited layer. The adhesives were applied to self-etching primer-treated dentin surfaces of bovine incisors, after which the teeth were light-irradiated and the oxygen-inhibited layer was left intact or removed with ethanol. We determined surface free energies (γS) and their components by measuring the contact angles of three test liquids placed on the cured adhesives. We also measured the dentin bond strengths of chemically cured resin composite to the adhesives, with and without the oxygen-inhibited layer. For all surfaces, the estimated surface tension component, γSLW, was relatively constant. The Lewis base (γS−) component decreased significantly when the oxygen-inhibited layer was removed, whereas the Lewis acid (γS+) component slightly increased. The dentin bond strengths of the two-step self-etch systems did not significantly differ in relation to the presence of the oxygen-inhibited layer. Although the surface free energy of the adhesive was affected by the presence of the oxygen-inhibited layer, no changes in dentin bond strength were detected. (J Oral Sci 56, 201-207, 2014)
To study the relationship between the biological and morphological characteristics of oral intraepithelial neoplasms (OINs), we examined the localization of desmosome-related proteins. Twenty-seven cases of OIN3 were tentatively classified as basaloid (14 cases) or differentiated (13 cases), and the latter were further subdivided into verrucous (five cases) and acanthotic (eight cases) subtypes. All samples were stained using antibodies against desmoglein 1 (DSG1), desmocollin 3 (DSC3), junction plakoglobin (JUP) and serine peptidase inhibitor Kazal type 5 (SPINK5) domain. All variants of OIN3 showed significantly high rates of positivity for DSG1 in the basal layer (basaloid 57%; differentiated 85%), DSC3 in the surface layer (basaloid 93%; differentiated 77%) and JUP in the basal and parabasal layers (basaloid 93%; differentiated 62%). Interestingly, even the basaloid type showed areas of alternating DSG1 positivity and negativity, reflecting keratinocyte maturation. Therefore, most cases of OIN appear to have the characteristics of well differentiated squamous epithelium. (J Oral Sci 56, 209-214, 2014)
We compared the apical seals of two new calcium silicate-based sealers (iRoot SP and MTA Fillapex) in the presence and absence of a smear layer. Eighty-two human premolars were prepared and randomly divided into four groups. In groups 1 and 3, the smear layer was retained. In groups 2 and 4, the root canals were irrigated with EDTA to remove the smear layer. Canals were filled using gutta-percha/iRoot SP (in groups 1 and 2) or obturated with gutta-percha/MTA Fillapex (in groups 3 and 4). Fluid filtration was used to evaluate apical microleakage. The presence of the smear layer had no significant effect on the sealing properties of the filling materials, except for iRoot SP at 2 weeks (P = 0.007). There was significantly less microleakage with iRoot SP than with MTA Fillapex (P = 0.025 at 2 weeks; P < 0.001 at 3 months). Leakage decreased significantly over time in all specimens, except in group 2 (P = 0.473). In conclusion, removal of the smear layer had no adverse effect on the sealing properties of calcium silicate-based sealers. In addition, the sealing ability of iRoot SP was superior to that of MTA Fillapex. (J Oral Sci 56, 215-219, 2014)
We investigated the relationship between pain intensity and psychosocial characteristics in patients with temporomandibular disorder (TMD). Participants with painful TMD, according to the Research Diagnostic Criteria for TMD (RDC/TMD), were recruited from our clinic and classified into six age groups: 15 to 24, 25 to 34, 35 to 44, 45 to 54, 55 to 64, and 65 to 85 years (Groups A through F, respectively). Self-reported present pain intensity and worst pain intensity during the past 6 months were ascertained using a numeric rating scale (0 to 10). Depression and somatization scores were evaluated using the RDC/TMD axis II questionnaire. Among women, worst pain intensity was significantly lower in Groups E and F than in Groups B and C (P < 0.05). In Groups A, C, and D, depression scores were significantly higher in women than in men (P < 0.05). Among women, depression score was significantly lower in Group F than in Groups A through C (P < 0.05). In Groups A through D, somatization scores were significantly higher for women than for men (P < 0.05). Depression score and TMD symptom severity appear to decrease with age in women. (J Oral Sci 56, 221-225, 2014)
This report describes the bonding technique and clinical course of porcelain laminate veneer restorations applied to discolored maxillary incisors and canines. The patient was an 18-year-old woman, and tooth reduction was limited to the enamel. Laminate veneer restorations were made with a feldspathic porcelain material (Cosmotech Porcelain). After try-in, enamel surfaces were etched with 65% phosphoric acid gel, and a tri-n-butylborane-initiated resin (Super-Bond C&B) was applied as a bonding agent. The inner surface of the restorations was etched with 5% hydrofluoric acid gel (HF Gel) and treated with a two-liquid silane primer (Porcelain Liner M), after which the Super-Bond resin was applied. Each restoration was seated with a dual-activated composite luting agent (Cosmotech Composite). After 24 years and 8 months, the restorations are functioning satisfactorily. The luting system and bonding technique described in this report are an option for seating laminate veneer restorations made of silica-based tooth-colored ceramics. (J Oral Sci 56, 227-230, 2014)
It is often very difficult to replant avulsed teeth in the deciduous and mixed dentition when the cortical bone is fractured and there are no adjacent teeth for anchorage. In this article, we describe the management of avulsed maxillary incisors in a 7-year-old boy. The avulsed teeth could be successfully repositioned by intra-alveolar transplantation using the 180° rotation (buccolingual reverse) method, which was originally applied to preserve teeth with relatively deep subgingival crown-root fracture, and a vacuum-formed splint was used for fixation. The avulsed teeth were followed up for 42 months. The post-operative course was uneventful with an aesthetic and functionally stable outcome. (J Oral Sci 56, 231-234, 2014)
Accidental ingestion of instruments or their components is a possible complication of dental treatment. Although in many cases the foreign object can pass through the gastrointestinal tract without any need for surgical intervention to retrieve it, sometimes such incidents can be life-threatening. This paper reports a case of accidental ingestion of an air-water syringe tip during routine dental treatment for which endoscopic retrieval was required. The present case highlights the need for dental professionals to be aware of the fact that dental equipment comprising multiple components may be associated with a risk of accidental detachment of a component and its ingestion or aspiration by a patient receiving treatment. (J Oral Sci 56, 235-238, 2014)
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