سال:1393 | دوره: | شماره: |تعداد مقالات:8

Replacement and reattachment of a newly detached composite tooth pontic is sometimes justified because of shape, color, function and patient satisfaction.The aim of this case report is to describe a new method using Rigid Tray Technique for exact replacement and reattachment of acceptable detached composite tooth pontic.

Introduction: This in vitro study investigates the marginal and internal fit of indirect class II composite restorations. Two different processes for chair-side restorations were compared. In group A, the restorations were fabricated using CAD/CAM technology (Cerec, Sirona, Germany, Bernsheim) and in group B they were made by hand (GrandioSO Inlay System, VOCO GmbH, Germany, Cuxhaven).Methods: For a metal tooth with a MOD cavity each 10 restorations were made for groups A and B. For each restoration, a replica of the cement-gap made from light body silicone was produced by placing the restoration into the cavity of the metal tooth. For this purpose, a special restoration-positioning machine was developed. Each replica was sectioned off in the longitudinal axis (L) and in the cross axis (C). The thickness of the replicas was measured in both directions, using picture analysis software under a light reflection microscope. To evaluate the fit of the restorations, a special fitting parameter was calculated. Statistical analysis was performed with the t test.Results: The fitting-parameter in group B (L: 97.6mm±73.0mm; C: 71.8mm±46.4mm) was significantly lower than that of group A (L: 155.1mm±102.3.0mm; C: 168.2mm±91.9mm) (P<0.001).Conclusions: Within the limitations of this in-vitro study hand-made composite restorations using the GrandioSO Inlay System seems to be a good alternative to CAD/CAM production. The clinical success of these restorations has to be evaluated in further studies.

Introduction: This study aimed to evaluate the effect of pretreatment with a neutral fluoride agent on shear bond strength (SBS) and microleakage of orthodontic brackets, and to investigate any significant relationship between SBS and microleakage.Methods: Forty intact premolars were selected and randomly divided into 2 groups. Group 1 served as the control, while group 2 underwent treatment with a 2% sodium fluoride (NaF) gel, which was applied on the enamel surface for 4 minutes before etching. After bonding orthodontic brackets, the teeth were immersed for 12 hours in methylen blue dye, followed by mounting in acrylic resin. Shear bond strength was determined using an Instron Universal Testing Machine and the amount of microleakage and the adhesive remnant index (ARI) were assessed under a stereomicroscope.Results: The mean SBS and microleakage beneath metal brackets were not significantly different among the control and NaF-treated groups (P>0.05). Furthermore, no significant correlation was found between SBS and microleakage (r=-0.04, P=0.796). The ARI scores revealed that in both groups, most of the adhesive remained on the enamel surface after debonding.Conclusions: It may be concluded that pretreatment of enamel with 2% NaF prior to the bonding procedure does not significantly affect microleakage and SBS of orthodontic brackets and thus, it can be recommended as a suitable approach to reduce the incidence of white spot lesions in orthodontically treated patients, especially those at high risk of caries formation.

Introduction: The purpose of this study was to evaluate the sealing ability of 3 obturation techniques in oval-shaped canals by bacterial leakage assessment.Methods: Sixty mandibular incisors with oval canals were selected after providing buccolingual and mesiodistal radiographs. The teeth were sectioned at a 10 mm distance from the apex. After instrumentation, the teeth were divided into 3 groups and the canals in the three groups were obturated with lateral condensation (G1), warm vertical condensation (G2) and thermoplasticized injectable gutta percha (G3). The teeth were exposed to human saliva. Observing the turbidity of the BHI broth for a period of 63 days the number of days required for the complete contamination of root canals was recorded. The data were analyzed using descriptive statistical methods and Kruskal-Wallis test with SPSS statistical software.Results: Warm vertical condensation (G2) needed a significantly greater average time for leakage than the two other methods. No significant differences were found between lateral condensations and thermoplasticized injectable G.P techniques.Conclusion: warm vertical condensation provides a better seal against bacterial leakage than lateral condensation and obtura II method in obturating oval-canals.

Introduction: The aim of this study was to assess the galvanic behavior of different bracket and archwire combinations that are commonly used in orthodontic treatments.Methods: Three types of orthodontic archwires with a diameter of 0.016×0.022 inch and 80 standard edgewise maxillary central incisor brackets were selected. Three groups consisted of different wire-bracket couples and one group was just brackets as a control group. Each group had five samples. Four brackets were then connected to each wire by elastic bands made from electrochemically neutral material. The samples were immersed into capped containers of Fusayama-Meyer artificial saliva. After six weeks, the released nickel ions were quantified via ion absorption technique. The mean and the standard deviation of all four groups were calculated and the data were compared together with Kruskal-Wallis non-parametric statistical test.Results: The highest concentration of released nickel ions was for bracket+steel archwire and the least for the bracket without archwire.Conclusion: There were not significant differences among experimental groups, so it could be concluded that galvanic corrosion would not be a serious consideration through orthodontic treatment.

Introduction: One of the most common problems we confront in orthodontic therapy is periodontal diseases. Initial factor which causes these diseases is colonization of anaerobic microorganisms in subgingival plaque. Technically, local environmental changes related to orthodontic band and brackets may influence the bacterial species in periodontal plaque. However, it seems necessary to assess variations in subgingival plaque caused by orthodontic appliances. The aim of this study was to investigate changes in subgingival microbiota and clinical parameters before and after bracket placement.Methods: Clinical parameters including probing depth (PD), plaque index (PI), clinical attachment level (CAL), bleeding on probing (BOP) and gingival index (GI) were recorded and subgingival microbial samples were collected in 30 people aged between 13 and 25. As a control group, 15 persons getting matched as to their age and sex with no need to orthodontic treatment were opted using specific primers, SYBER Green Real-Time PCR was carried out in order to determine bacterial flora in stored samples. All mentioned procedures were reassessed in experimental group and in control group three months after band and bracket bonding. A descriptive analysis was conducted, and paired t test and Wilcoxon test were used for differences between groups (P<0.05).Results: No changes in clinical attachment level were observed, but scores for bleeding on probing, plaque index, and gingival index increased 3 months after bracket placement in experimental group (P<0.05). Prevotella intermedia rose in experimental group after brackets placement compared with control group but Actinobacillus actinomycetem comitans and Tanerella forsythia proportions did increase.Conclusions: treatment with fixed appliances may transitionally raise the growth of periodontopathogenic bacteria and consequently result in gingival inflammatory response but without destructive effect on deep periodontal tissues.

Salivary mucocele is a common lesion derived from minor salivary glands with various surgical or non-surgical treatment modalities. To evaluate the effect of a highly potent corticosteroid (dexamethasone) in the management of salivary mucocele, we performed intralesional injection of dexamethasone in nine patients with labial mucocele. Complete healing of lesions observed in seven of nine patients, and size reduction in two of them. No local scarring or deformity of the lower lip occurred in any of the patients. One patient reported local discomfort at the site of injection. Intralesional injection of dexamethasone is a potentially curative method in the treatment of mucocele.

Kindler syndrome (KS) is a rare, autosomal recessive genodermatosis characterized by skin blistering and photosensitivity in infancy, progressive poikiloderma, and diffuse cutaneous atrophy. It affects the skin, mucous membranes, and oral cavity and is caused by mutations in the KIND1 gene on 20p12.3. The first case of KS associated with periodontitis was reported in 1996, and have been infrequently reported since. Here we present a case of KS with classic clinical presentations involving skin, mucous membranes, and the periodontium in a patient from Iran.