Comparison of the bond strength of ceramics to Co-Cr alloys made by casting and selective laser melting

PURPOSE: Considering the importance of metal-ceramic bond, the present study aimed to compare the bond strength of ceramics to cobalt-chrome (Co-Cr) alloys made by casting and selective laser melting (SLM). MATERIALS AND METHODS: In this in-vitro experimental study, two sample groups were prepared, with one group comprising of 10 Co-Cr metal frameworks fabricated by SLM method and the other of 10 Co-Cr metal frameworks fabricated by lost wax cast method with the dimensions of 0.5 × 3 × 25 mm (following ISO standard 9693). Porcelain with the thickness of 1.1 mm was applied on a 3 × 8-mm central rectangular area of each sample. Afterwards, bond strengths of the samples were assessed with a Universal Testing Machine. Statistical analysis was performed with Kolmogorov-Smirnov test and T-test. RESULTS: Bond strength in the conventionally cast group equaled 74.94 ± 16.06 MPa, while in SLM group, it equaled 69.02 ± 5.77 MPa. The difference was not statistically significant (P ≤ .05). CONCLUSION: The results indicated that the bond strengths between ceramic and Co-Cr alloys made by casting and SLM methods were not statistically different.

Effect of GLUMA desensitizer on the retention of full metal crowns cemented with Rely X U200 self-adhesive cement

PURPOSE: Considering the importance of retention in the success and long-term clinical service of fixed partial dentures (FPDs) as well as the existing controversy regarding the effect of GLUMA desensitizer on the retention of full metal crowns cemented with RelyX U200 self-adhesive cement, this study aimed to assess the effect of GLUMA desensitizer on the retention of full metal crowns cemented using RelyX U200. MATERIALS AND METHODS: In this experimental study, 20 sound human premolars were prepared; a 0.5 mm chamfer finish line was prepared above the cementoenamel junction. The teeth were randomly assigned to two groups: a desensitizer group (n = 10, treated with GLUMA desensitizer) and a control (n = 10, no surface treatment). Full metal crowns were fabricated of base metal alloy and had a ring. All crowns were cemented with RelyX U200 and subjected to retention test by using a universal testing machine. The data were analyzed using SPSS version 20 and independent t-test. RESULTS: The mean tensile bond strength was significantly higher in the GLUMA desensitizer group (230.63 ± 63.8 N) compared to the control group (164.45 ± 39.3 N) (P≤.012). CONCLUSION: GLUMA desensitizer increases the tensile bond strength of RelyX U200 self-adhesive cement to dentin.

management of oral pemphigus vulgaris with systemic corticosteroid and dapsone

Oral pemphigus vulgaris is a chronic autoimmune mucocutaneous intraepithelial disease that primarily affects patients over the age of fifty, resulting in mucosal ulceration and is a potentially life-threatening disease. The purpose of this study was to investigate the efficacy of dapsone in combination with systemic corticosteroids to treat the oral lesions of oral pemphigus. Twenty patients diagnosed with oral pemphigus were selected. Oral manifestations were graded according to the severity of disease from 1 to 3. All patients were treated initially with systemic corticosteroids. Each was assigned to one of 4 groups according to their response to therapy. Patients who responded less than 50% healing of lesions began a trial of dapsone. After 4 weeks, signs and symptoms were recorded, and if a patient was lesion-free, the dapsone dosage was gradually tapered. Five patients with mild to moderate disease were treated with systemic corticosteroids alone. 15 patients with moderate to severe disease were treated with systemic corticosteroid and dapsone therapy. Of these, 10 patients had significant benefits, while 5 patients did not respond to dapsone adjuvant. The use of dapsone in combination with systemic corticosteroids is a useful method for treatment of oral pemphigus

Effects of Low-level laser in the treatment of myofascial pain dysfunction syndrome

Muscular pain in the facial region is the most common cause of facial pains. Myofascial pain dysfunction syndrome [MPDS] is one of the most important facial muscle disorders comprising of signs and symptoms including pain during function, tenderness in the muscles of mastication and restricted jaw movement. Due to the lack of an accepted therapeutic approach, the purpose of this paper was to find an effective treatment to decrease the pain of such patients. Considering the analgesic and anti-inflammatory action of laser therapy, the effects of low level laser [Ga-Al-As] in the treatment of MPDS patients referred to Tehran University of Medical Sciences Faculty of Dentistry, were investigated in the present study. This study was a quasi-experimental research. Twenty-two MPDS patients were selected from those referred to Department of Oral Medicine, Tehran University of Medical Sciences Faculty of Dentistry. Clinical examination was performed at six stages in the following order: prior to the treatment, at 2 and 4 weeks after treatment, and monthly thereafter for a 3-months follow-up. All patients underwent low-level laser therapy for 4 weeks [12 sessions]. Variables such as pain severity, pain of cheek region, pain frequency, tenderness of masticatory muscles, click, and mouth opening were evaluated at each stage. Numerical variables were investigated using Analysis of Variance test for repeated measures whereas ranking variables were studied by non-parametric Kruskal-Wallis test. At the end of treatment period, pain severity, pain of cheek region, pain frequency, tenderness of masseter, temporalis, medial pterygoid, and lateral pterygoid muscles showed significant improvement as compared with the commencement of any treatment which continued during the 3-months post-treatment [p < 0.05]. It was shown that low-level laser [Ga-Al-As] therapy had the efficacy to alleviate pain and decrease the tenderness of masticatory muscles among MPDS patients through a continuous and regular therapeutic program

comparison of efficacy of adcortyl ointment and topical tacrolimus in treatment of erosive oral Lichen Planus

Oral lichen planus [OLP] is a common chronic mucocutaneous disease. Patients with atrophic and erosive lichen planus often have symptoms of soreness and need proper treatment. The main therapy of OLP has been the administration of topical or systemic corticosteroids. Potent topical corticosteroids have been increasingly prescribed in the treatment of erosive lichen planus. The purpose of this study was to compare the efficacy of adcortyl ointment [triamcinolone in orabase] with topical tacrolimus for the treatment of erosive oral lichen planus. Sixty Patients with histopathologically confirmed oral lichen planus were enrolled in the study. The severity of lesions was scored from 0 to 5 according to the criteria described in a previous study. Patients were randomly given adcortyl [group A] and topical tacrolimus ointment [group B] and asked to apply the medication on dried lesions 4 times a day. The lesions were evaluated after 4 weeks of treatment. Visual analogue scale was used to assess the severity of pain before and after treatment. The severity scores were analyzed using the Kruskal-Wallis k-sample test. The average score of lesions improved from 3.4 to 1.5 in patients who received adcortyl ointment and from 3.2 to 1.2 in patients who received topical tacrolimus ointment. The differences between the improvements in scores were not statistically significant in the two groups. The average pain severity in A and B groups was 8.2 and 7.8 at the beginning of treatment, and 3.5 and 3.2 at the end of treatment, respectively. There was a statistically significant reduction in pain severity in both groups. Topical tacrolimus is a safe and effective alternative therapy in the treatment of oral lichen planus