The aim of this study was to examine that thick dentin bonding agent application or low modulus composite restoration could reduce stresses on dentin bonding agent layer. A mandibular first premolar with abfraction lesion was modeled by finite element method. The lesion was restored by different composite resins with variable dentin bonding agent thickness (50microm, 100microm, 150microm). 170N of occlusal loading was applied buccally or lingually. Von Mises stress on dentin bonding agent layer were measured. When thickness of dentin bonding agent was increased von Mises stresses at dentin bonding agent were decreased in both composites. Lower elastic modulus composite restoration showed decreased von Mises stresses. On root dentin margin more stresses were generated than enamel margin. For occlusal stress relief at dentin boning agent layer to applicate thick dentin bonding agent or to choose low elastic modulus composite is recommended.
Bicuspid ; Composite Resins ; Dental Enamel ; Dentin ; Elastic Modulus

PURPOSE: This study assessed the axillary lymph node (ALN)-to-primary tumor maximum standard uptake value (SUVmax) ratio (ALN/T SUV ratio) in invasive ductal breast cancer (IDC) on preoperative 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) to determine the effectiveness in predicting recurrence-free survival (RFS). METHODS: One hundred nineteen IDC patients (mean age, 50.5+/-10.5 years) with pathologically proven ALN involvement without distant metastasis and preoperative FDG PET/CT were enrolled in the study. SUVmax values of the ALN and primary tumor were obtained on FDG PET/CT, and ALN/T SUV ratio was calculated. Several factors were evaluated for their effectiveness in predicting RFS. These included several parameters on FDG PET/CT as well as several clinicopathological parameters: pathologic tumor/node stage; nuclear and histological grade; hormonal state; status with respect to human epidermal growth factor receptor 2, mindbomb E3 ubiquitin protein ligase 1 (MIB-1), and p53; primary tumor size; and ALN size. RESULTS: Among 119 patients with breast cancer, 17 patients (14.3%) experienced relapse during follow-up (mean follow-up, 28.4 months). The ALN/T SUV ratio of the group with disease recurrence was higher than that of the group without recurrence (0.97+/-1.60 and 0.45+/-0.40, respectively, p=0.005). Univariate analysis showed that the primary tumor SUVmax, ALN SUVmax, ALN/T SUV ratio, ALN status, nuclear and histological grade, estrogen receptor (ER) status, and MIB-1 status were predictors for RFS. Among these variables, ALN/T SUV ratio with hazard ratio of 4.20 (95% confidence interval [CI], 1.74-10.13) and ER status with hazard ratio of 4.33 (95% CI, 1.06-17.71) were predictors for RFS according to multivariate analysis (p=0.002 and p=0.042, respectively). CONCLUSION: Our study demonstrated that ALN/T SUV ratio together with ER status was an independent factor for predicting relapse in IDC with metastatic ALN. ALN/T SUV ratio on preoperative FDG PET/CT may be a useful marker for selecting IDC patients that need adjunct treatment to prevent recurrence.
Breast Neoplasms* ; Electrons ; Estrogens ; Fluorodeoxyglucose F18* ; Follow-Up Studies ; Humans ; Lymph Nodes ; Multivariate Analysis ; Neoplasm Metastasis ; Positron-Emission Tomography and Computed Tomography* ; Prognosis ; Receptor, Epidermal Growth Factor ; Recurrence ; Ubiquitin-Protein Ligases

During clinical endodontic treatment, we often find radiopaque filling material beyond the root apex. Accidental extrusion of calcium hydroxide could cause the injury of inferior alveolar nerve, such as paresthesia or continuous inflammatory response. This case report presents the extrusion of calcium hydroxide and treatment procedures including surgical intervention. A 48 yr old female patient experienced Calcipex II extrusion in to the inferior alveolar canal on left mandibular area during endodontic treatment. After completion of endodontic treatment on left mandibular first molar, surgical intervention was planned under general anesthesia. After cortical bone osteotomy and debridement, neuroma resection and neurorrhaphy was performed, and prognosis was observed. But no improvement in sensory nerve was seen following surgical intervention after 20 mon. A clinician should be aware of extrusion of intracanal medicaments and the possibility of damage on inferior alveolar canal. Injectable type of calcium hydroxide should be applied with care for preventing nerve injury. The alternative delivery method such as lentulo spiral was suggested on the posterior mandibular molar.
Anesthesia, General ; Calcium Hydroxide* ; Calcium* ; Debridement ; Female ; Humans ; Mandibular Nerve* ; Molar ; Neuroma ; Osteotomy ; Paresthesia ; Prognosis

This study was conducted to evaluate the influence of the C-factor on the bond strength of a 6th generation self-etching system by measuring the microtensile bond strength of four types of restorations classified by different C-factors with an identical depth of dentin. Eighty human molars were divided into four experimental groups, each of which had a C-factor of 0.25, 2, 3 or 4. Each group was then further divided into four subgroups based on the adhesive and composite resin used. The adhesives used for this study were AQ Bond Plus (Sun Medical, Japan) and Xeno III (DENTSPLY, Germany). And composite resins used were Fantasista (Sun Medical, Japan) and Ceram-X mono (DENTSPLY, Germany). The results were then analyzed using one-way ANOVA, a Tukey's test, and a Pearson's correlation test and were as follows. 1. There was no significant difference among C-factor groups with the exception of groups of Xeno III and Ceram-X mono (p < 0.05). 2. There was no significant difference between any of the adhesives and composite resins in groups with C-factor 0.25, 2 and 4. 3. There was no correlation between the change in C-factor and microtensile bond strength in the Fantasista groups. It was concluded that the C-factor of cavities does not have a significant effect on the microtensile bond strength of the restorations when cavities of the same depth of dentin are restored using composite resin in conjunction with the 6th generation self-etching system.
Adhesives ; Composite Resins ; Dentin ; Dentin-Bonding Agents ; Humans ; Molar

This case report is to present a maxillary first molar with one O-shaped root, which is an extended C-shaped canal system. Patient with chronic apical periodontitis in maxillary left first molar underwent replantation because of difficulty in negotiating all canals. Periapical radiographs and cone-beam computed tomography (CBCT) were taken. All roots were connected and fused to one root, and all canals seemed to be connected to form an O-shape. The apical 3 mm of the root were resected and retrograde filled with resin-modified glass ionomer. Intentional replantation as an alternative treatment could be considered in a maxillary first molar having an unusual O-shaped root.
Adult ; Anatomic Variation ; Apicoectomy ; methods ; Cone-Beam Computed Tomography ; methods ; Dental Pulp Cavity ; diagnostic imaging ; pathology ; Glass Ionomer Cements ; therapeutic use ; Humans ; Male ; Maxilla ; Molar ; diagnostic imaging ; pathology ; Periapical Periodontitis ; therapy ; Retrograde Obturation ; methods ; Root Canal Filling Materials ; therapeutic use ; Root Canal Preparation ; methods ; Tooth Replantation ; methods