Effect of mineral trioxide aggregate plug location on root development in regenerative endodontic procedure.

This retrospective study investigated the effect of mineral trioxide aggregate (MTA) plug location on treatment outcome and root maturation after regenerative endodontic procedures (REP) in immature permanent teeth. Thirty-three roots (n = 33) in cohort that underwent REP consistently according to AAE guideline were included to trace radiographic changes for the root and canal dimensions. Based on intraoral radiographs, roots were divided into two groups depending on the location of MTA plug within whole root length: coronal group (n = 14), within the upper half; apical group (n = 19), within the lower half. Periapical radiographs were standardized to assess treatment outcomes and root maturation including root development stages and digital measurements on the change ratios of root length, apex width, radiographic root area (RRA), modified RRA (mRRA), and periapical rarefaction area. The data were statistically analysed using the Mann-Whitney test. The patients' average age was 11 years and 10 months, with no significant between-group difference in sex. Premolars were the most prevalent tooth type (62.1%), followed by incisiors and molars. Pre-existing symptoms and signs subsided within 6 months in all cases. The teeth showed similar radiographic root development in both groups (P > 0.05). However, mRRA increase ratio was significantly higher in apical group than that in coronal group at early (< 6 months) and late (< 24 months) periods of follow-up (P < 0.05). Significant changes of root development stage were observed at early period for apical group and at late period for coronal group (P < 0.05). All the observed cases showed continuing root development after REP. Significant changes in root developments occurred at different follow-up periods according to the location of MTA plugs.

Periapical Healing in Single-visit Endodontics under General Anesthesia in Special Needs Patients.

INTRODUCTION: The aim of this study was to determine the prognostic factors of periapical healing of teeth after single-visit nonsurgical endodontic treatment under general anesthesia in special needs patients. METHODS: This retrospective study collected 448 teeth from 241 patients (mean age = 27.4 years, standard deviation = 13.9 years). A total of 271 teeth (60.5%) with clinical and radiographic follow-up records longer than 12 months (mean [standard deviation] = 56.1 [27.9]) were included in the outcome analysis. Demographic, systemic, and dental information about the cases were compared between the healed and nonhealed groups using the Pearson chi-square test. Factors contributing to periapical healing were determined with multivariate logistic regression analysis. RESULTS: Complete periapical healing without clinical signs was observed in 221 teeth (81.5%), uncertain healing with decreased size of the periapical lesion was shown in 43 teeth (15.9%), and no reduction in lesion size was observed in 7 cases (2.6%). In the multivariate analysis, diet type, oral hygiene maintenance, pulp vitality, and root filling length were detected as contributing factors for complete resolution of periapical lesions (P < .05). CONCLUSIONS: Successful outcomes of single-visit endodontic treatment under general anesthesia were shown in special needs patients. The prognoses were influenced by the clinical circumstances of the patients and the preoperative conditions of their teeth.

Integrated PET/MR mammography for quantitative analysis and correlation to prognostic factors of invasive ductal carcinoma.

BACKGROUND: We investigated the relationship between 18F-FDG PET parameters and apparent diffusion coefficient (ADC) values obtained by diffusion weighted MRI (DWI) in patients with invasive ductal carcinoma (IDC). In addition, the prognostic utility of PET/MR mammography parameters was compared with that of known histologic prognostic factors. METHODS: Forty-six women aged 50.7±10.5 years underwent a preoperative PET/MR mammography assessment using an integrated PET/MR scanner. T1w, T2w, DWI (b value: 50, 400, and 800 s/mm2), dynamic contrast enhancement sequences, and 18F-FDG PET imaging were performed. IDCs were assessed using SUVmax values and intratumoral heterogeneities (IH) from the 18F-FDG PET images and mean (ADCmean) and minimum ADC (ADCmin) values were measured using the DWI images. Relationships between the PET parameters and ADC values were evaluated. Furthermore, SUVmax and ADC values were compared with histologic factors, tumor size, nodal status, lymphovascular invasion, Ki-67 expression and triple negative breast cancer (TNBC). RESULTS: In total 46 IDCs (2.1-7.5 cm in size) were analyzed. SUVmax (P=0.012) and elevated IH (P=0.041) were negatively correlated with ADCmin, then TNBC (P=0.013) and high Ki-67 expression (P=0.002) were associated with higher SUVmax. IDC with lymphovascular invasion had low ADCmin values (P=0.045). CONCLUSIONS: 18F-FDG PET metabolic parameters and ADCmin were negatively correlated. PET parameters and ADC values might reflect the expression of biological features of tumors and tumor invasiveness, respectively. Integrated PET/MR mammography seemed like to have potential of a one-stop method for evaluating and predicting the prognosis of IDC.

Evaluation of the safety and efficiency of novel metallic implant scaler tips manufactured by the powder injection molding technique.

BACKGROUND: Although many studies have compared the properties of ultrasonic scaling instruments, it remains controversial as to which is most suitable for implant scaling. This study evaluated the safety and efficiency of novel metallic ultrasonic scaler tips made by the powder injection molding (PIM) technique on titanium surfaces. METHODS: Mechanical instrumentation was carried out using four types of metal scaler tips consisting of copper (CU), bronze (BR), 316 L stainless steel (316 L), and conventional stainless steel (SS) tips. The instrumented surface alteration image of samples was viewed with scanning electron microscope (SEM) and surface profile of the each sample was investigated with confocal laser scanning microscopy (CLSM). Arithmetic mean roughness (Ra) and maximum height roughness (Rmax) of titanium samples were measured and dissipated power of the scaler tip was estimated for scaling efficiency. RESULTS: The average Ra values caused by the 316 L and SS tip were about two times higher than those of the CU and BR tips (p < 0.05). The Rmax value showed similar results. The efficiency of the SS tip was about 3 times higher than that of CU tip, the 316 L tip is about 2.7 times higher than that of CU tip, and the BR tip is about 1.2 times higher than that of CU tip. CONCLUSIONS: Novel metallic bronze alloy ultrasonic scaler tip minimally damages titanium surfaces, similar to copper alloy tip. Therefore, this bronze alloy scaler tip may be promising instrument for implant maintenance therapy.