Active tactile sensibility of three-unit implant-supported FPDs versus natural dentition

Splinting of the implants might improve the active tactile sensibility (ATS) of the pontic area due to cumulative effect of Osseo perception of two retainers; on the other hand, due to the lack of any supporting implant in the axis of occlusal force for the pontic area, ATS might be lower for this portion of FPDs. we evaluated the active tactile sensibility of natural teeth and three-unit implant-supported FPDs. The ATS of posterior 3-unit implant-supported FPD and contralateral teeth was measured in 50 patients, in a random order blinded to patients and assessor, carried out at two sessions. Based on the experimental range of 0 to 70 um, the sigmoid shape of psychometric curve was estimated to locate the 50% values as the ATS thresholds for each tooth or implant. Data were analyzed using unpaired t-tests. The ATS of the teeth and implants differed significantly and compared to teeth, implants exhibited significantly higher ATS thresholds in all the groups. The results of independent t-test showed the highest difference in the means of ATS between the pontic and the first molar tooth. Based on the equivalence testing approach, the 95% CIs indicated that the differences were clinically significant only in the Pontic/First Molar group. In multi-unit implant-supported prostheses the tactile perception of the prosthesis that are placed on fixtures is similar to the natural teeth. In pontic areas there are significant statistical and clinical differences, with much lower tactile sensibility in pontics compared to the natural teeth

The Antibacterial Efficacy of Photo-Activated Disinfection, Chlorhexidine and Sodium Hypochlorite in Infected Root Canals: An in Vitro Study

Introduction: This study compared the efficacy of light-activated low-power laser, 2% chlorhexidine (CHX) and 2.5% NaOCl in eliminating Enterococcus faecalis (E. faecalis) from the root canal system. Methods and Materials: The root canals of 60 maxillary central incisors were contaminated with E. faecalis and then the bacteria were incubated for 24 h. All the root canals were instrumented in a crown-down manner with #4 and 3 Gates-Glidden drills, followed by RaCe rotary files (40/0.10, 35/0.08, and 30/0.06). The samples were randomly assigned to three experimental groups and one control group (n=15). In the control group no intervention was made. In the photo-activated disinfection (PAD) group, laser therapy was undertaken with diode laser beams (with an output power of 100 mW/cm2) for 120 sec. For the other two experimental groups, root canals were irrigated either with 5 mL of 2% CHX or 2.5% NaOCl solutions, respectively. The Kruskal-Wallis test was used to compare the CFU values of the bacteria and post-hoc Bonferroni test was used for pairwise comparisons. The level of significance was set at 0.05. Results: The inhibition of bacterial growth in all the experimental groups was significantly superior to the control group (P<0.05). There was no significant difference between the effect of PAD and 2% CHX (P=0.05). The effect of 2.5% NaOCl was significantly better than that of the PAD technique (P<0.001). In addition, 2.5% NaOCl was significantly better than 2% CHX (P=0.007). Conclusion: Photodynamic therapy was effective in reducing the E. faecalis counts in comparison with the control group, but 2.5% NaOCl solution was the most effective protocol.Keywords: Enterococcus faecalis; Laser; Photo-Activated Disinfection; Photodynamic Therapy; Sodium Hypochlorit

Curcumin Nanocrystals: Production, Physicochemical Assessment, and In Vitro Evaluation of the Antimicrobial Effects against Bacterial Loading of the Implant Fixture

Background: This study aimed to prepare and study physicochemical properties as well as the antibacterial action of curcumin nanocrystals inside the implant fixture against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Enterococcus faecalis (E. faecalis). Methods: Curcumin nanocrystals were prepared via precipitation combined with the spray drying method. The produced curcumin nanocrystals were characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), and Fourier transform infrared spectroscopy (FTIR). Moreover, the in vitro antimicrobial effect of curcumin nanocrystals inside the implant fixture was assessed against E. coli, S. aureus, and E. faecalis. All implant-abutment assemblies were immersed in bacterial suspensions and were incubated at 24, 48, and 72 h. The contents of each implant were cultured to count the colony of bacteria at 37 ◦C for 24 h. Results: The prepared curcumin nanocrystals with a mean particle size of 95 nm and spherical morphology exhibited a removal rate of 99.99% for all bacteria. In addition, the colony-forming unit (CFU) of bacteria in exposure to nanocrystals significantly was reduced (p < 0.010) by increasing the time. Conclusions: Curcumin nanocrystals can be used inside the implant fixture as an antimicrobial agent in order to more stabilization of the implant

The Comparison of Job Stress among Dental Professionals of Dentistry Faculty Members of Tabriz University

Several studies have so far focused on occupational stress among dentists and the results have shown that many factorscan cause stress. However, the level of stress among experts in the fields of dentistry has not yet been studied in Iran.The aim of this study is to examine the causes and levels of job stress among dental professionals in Tabriz University ofMedical Sciences. This cross-sectional study included all dental professionals of Dentistry Faculty; an overall of 55 subjectsin Tabriz were studied in this research and their level of stress was evaluated using “The Health and Safety ExecutiveManagement Standards Indicator Tool” (HSE stress questionnaire) from September up to October 2014. The level of stressin each dental specialty was examined descriptively (mean, standard deviation). Statistical analysis was performed usingSPSS 20. The findings of the study showed that the highest stress among dental professionals from different fields wasobserved in the field of oral and maxillofacial radiology; fields of oral medicine, endodontics, oral and maxillofacial surgeryand pediatric dentistry ranked later. The lowest stress was seen among orthodontics specialists. Based on the results of thepresent study, the rate of job stress varied significantly among dental professionals

Compatibility of Clinical and Histopathological Diagnosis of Oral Lesions in Iranian Patients

Objective: To determine compatibility between clinical diagnosis and the pathological reports of biopsies from oral lesions. Material and Methods: In this descriptive study, 1146 clinical files of patients referring to Tabriz Faculty of Dentistry from 2004 to 2016 were retrieved and evaluated. The kappa coefficient was calculated for each file for compatibility of clinical and pathological diagnosis. Results: In relation to clinical (40.2%) and pathological (39.2%) diagnosis, irritational lesions of soft tissues exhibited the highest frequency. In 72.3% of cases, the clinical and pathological diagnosis were compatible and in 27.7% of cases these diagnosis were not compatible. The highest compatibility rates were detected for irritational lesions of soft tissues (81.5%) and mucocutaneous lesions (76.9%). There was no compatibility for osseous malignant tumors, inflammatory tissues, granulation tissues, metastatic lesions and hematologic disorders. Conclusion: Approximately one-third of clinical and histopathological diagnosis were not compatible. Therefore, to reach a correct diagnosis, the clinical, radiographic and histopathological views should be evaluated simultaneously

Rehabilitation of a Partial Nasal Defect with Facial Prosthesis: A Case Report

Malignancies of the midface result in cosmetic deformities that make maxillofacial prosthesis as an integral part of the treatment plan. Facial defects can be devastating in their impact on physical structure and function of the affected individual, leading to potentional compromises in quality of life. Reconstruction of nasal defects is a challenge for the prosthodontist because of esthetic and retention problems associated with the facial prosthesis. This paper reports the rehabilitation of a partial nasal defect caused by basal cell carcinoma treatment using a nasal prosthesis made with silicone elastomers and mechanical and anatomical retentive aids. The patient had no problem with the prosthesis, except for a partial loss of extrinsic coloration in the two-year follow-up