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.

Head and neck metastatic tumors: a retrospective survey of Iranian patients

Statement of the Problem: The head and neck region is an uncommon site for metastatic involvement, but it can be the first and only symptom of primary cancer. The incidence of these tumors and their primary origins are limited in Iranian patients

Purpose: Therefore, this retrospective study aimed to investigate the frequency and the common related clinical manifestations, as well as, the most common types of cancers and the prevalent sites of the primary tumor

Materials and Method: All medical records related to patients with history of head and neck tumors between 1991 and 2011 at Iran Cancer Institute were evaluated and the essential information was statistically analyzed

Results: Sixty cases of cervical lymph node metastasis [0.36%] and 26 cases of head and neck metastatic tumors [0.16%] including 17 cases of distant cancer [0.10%] were recorded among all 16232 registered cancers. Out of all distant head and neck metastatic tumors, 4 cases were related to oral and maxillofacial area. Pain, swelling of neck, oral mucosa ulcer and dryness were the chief complaints. Squamous cell carcinoma and adenocarcinoma were the most frequent types of cancers. The most common metastatic sites were cervical musculature, scalp and parotid gland, and the most prevalent sites of primary tumor in females were breast and lung in males

Conclusion: According to these cases, the incidence rate of head and neck metastatic tumors seems to be low. However, feasible similarity of clinical presentation of oral metastatic lesions to benign lesions might result in misdiagnosis. Hence, biopsy is mandatory in any case with unusual clinical presentation, especially in patients with a known malignant disease

Efficacy of topical and systemic vitamin E in preventing chemotherapy-induced oral mucositis

Background: There is still no consensus regarding the optimum treatment of chemotherapy-induced oral mucositis and its management is still mainly supportive. Vitamin E has been shown to be effective in reducing the symptoms of oral mucositis

Objectives: Aim of this study was to assess the efficacy of prophylactic systemic and topical vitamin E in reducing the signs and symptoms of oral mucositis in patients receiving chemotherapy

Patients and Methods: We conducted a placebo-controlled randomized clinical trial among 76 patients with a hematologic malignancy treated with chemotherapy. Patients were randomly assigned into three groups: supplementation with vitamin E paste [group 1] and 200 mg/d vitamin E pills [group 2]. Group 3 received placebo paste, identical in appearance and taste to the vit E paste, but consisting of the vehicle only. Patients were advised to use the administered medication from two days before each cycle of chemotherapy till at least 20 days after completion of each cycle. Oral exam was performed 10-14 days after each cycle of chemotherapy

Results: Patients in group 2 and 3 did not show any difference in degree of mucositis or severity of pain. However, after the second cycle, patients who were treated with topical vitamin E showed significantly less oral pain, and had fewer cases of severe mucositis compared to groups 2 and 3

Conclusions: Topical vitamin E could be beneficial in reducing the severity of oral mucositis, but no therapeutic gain would be achieved by using systemic vitamin E in this regard

In vitro effects of four porcelain surface treatment methods on adhesion of lactobacilli acidophilus

Objective: Adhesion of Lactobacillus acidophilus [L. acidophilus] to dental porcelain surface may lead to gingival inflammation and secondary caries. Surface roughness is among the factors affecting this adhesion. The purpose of this study was to evaluate the effects of four different surface treatment methods on adhesion of L. acidophilus to dental porcelain

Methods: Sixty specimens [3x10mm] were fabricated of Noritake porcelain and divided into 4 groups [n=15] treated with one of the following four surface finishing techniques: 1. Auto-glazing; 2. Over-glazing; 3. Polishing with Kenda kit and 4. No surface treatment [non-glazed specimens]. Specimens were inoculated with bacterial suspension containing 1x10[6]colony forming units per milliliter [CFU/mL] and L. acidophilus adhesion to the surfaces was evaluated using a spectrophotometer. Data were analyzed using one-way ANOVA and Tukey's HSD test

Results: The mean bacterial adhesion was 0.1440 [0.00429] to auto-glazed specimens, 0.0750 [0.00256] to over-glazed specimens, 0.1800 [0.00325] to polished specimens and 0.7064 [0.00408] to the non-glazed specimens. The differences in this regard among groups were statistically significant [p<0.001]

Conclusion: Over-glazed specimens caused the lowest and non-glazed specimens caused the highest bacterial adhesion. The glazed surfaces caused less adhesion than the polished surfaces

[Comparison of amount of salivary total antioxidant in patients with recurrent aphtous stomatitis]

Recurrent aphthous stomatitis [RAS] is the most common oral mucosal inflammatory disease. The frequency of RAS is as much as 20% in the general population. The cause of RAS is not yet fully understood. Antioxidant is a material which has ability to preserve molecules from damage and also can delay the start of it. The aim of this study was to compare the saliva level of total antioxidant status [TAS] in RAS patients with that of normal subjects. In this case-control study, 25 patients with aphthous stomatitis were considered as the case group and 25 healthy subjects as control group. The case and control groups were matched by sex and age. Total antioxidant status [TAS] saliva levels were measured in two groups by spectrophotometer. The data were analyzed with independent sample t-test. The mean and standard deviation of TAS in case group was 1.64 +/- 0.64 micro mol/L and in control group was 1.49 +/- 0.3 micro mol/L. There was not significant difference between case and control groups [P=0.464]. Results of this study showed that there was no statistically significant difference between RAS patients and healthy subjects in saliva antioxidant status levels

In vitro evaluation of the effect of three mouthwashes on microhardness of a composite resin

Regular application of mouthwashes has been recommended for the prevention and control of caries and periodontal diseases. Use of mouthwashes can affect restorative dental materials. The purpose of this in vitro study was to investigate the effect of three commercially available mouthwashes [Irsha, Chlorhexidine, Oral-B] in Iran on the microhardness of Z100 composite resin. In this in vitro experimental study 30 cylinders of composite resin were fabricated and stored in distilled water for 24 hours. Vickers hardness [VH] values of the samples were measured using Vickers hardness tester. The samples were stored in the mouthwashes for 12 hours, which was equivalent to two minutes of daily mouthwash application for a year. Microhardness values were measured again after immersion in the mouthwashes. Data was analyzed with ANOVA and Tukey test [alpha = 0.05]. Means of microhardness values for composite resin samples stored in Irsha, chlorhexidine and Oral-B mouthwashes were -1.94 +/- 0.23, -16.14 +/- 0.7 and -7.37 +/- 1.4, respectively. Differences in microhardness values in the Irsha group were higher than the two other groups, with statistically significant differences [p value < 0.05]. Under the limits of the present study it was concluded that various mouthwashes do not exert the same influences on the microhardness of composite resins. Chlorhexidine exerted the least influence on microhardness among the three mouthwashes under study

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