Evaluation of the risk of a stripping perforation with gates-glidden drills: serial versus crown-down sequences

The aim of this study was to evaluate the remaining dentine/cementum thickness using Gates-Glidden burs in serial and crown-down sequences and to observe which of the two sequences is the safest for preparing mesial roots of molars. Thirty-six left and right human mandibular first molars were selected. Standard access cavities were made and initially explored with Flexofiles sizes 10 and 15 until the tip was visible at the apex. The teeth were embedded in a muffle specially developed for this study using a PVC tube with two parallel metal rods in its lid. Each tooth-block was sectioned 3 mm apically to the furcation using a low-speed saw with a diamond disc. The tooth-block was examined under a microscope and an initial image was captured by a digital video system with 8 X and 12 X magnifications. Finally, the tooth-blocks were reassembled in the muffle so that the canals could be instrumented. After instrumentation the area of each mesial canal as well as the smallest distance to the root furcation were measured again. The mesio-buccal canals (crown-down order) and the mesio-lingual canals (serial sequence) presented an average area of 0.46 ± 0.16 mm² and 0.88 ± 0.27 mm² (P < 0.01), respectively. The mean values of the smallest distance to the furcation for the mesio-buccal and mesio-lingual canals were 0.66 ± 0.19 mm and 0.39 ± 0.13 mm (P < 0.01), respectively. The remaining dentine/cementum thickness using Gates-Glidden burs was greater in the crown-down sequence than in the serial sequence

Comparison of the effects of TripleGates and Gates-Glidden burs on cervical dentin thickness and root canal area by using cone beam computed tomography

The search for new instruments to promote an appropriate cervical preparation has led to the development of new rotary instruments such as TripleGates. However, to the best of the authors' knowledge, there is no study evaluating TripleGates effect on the &#8220;risk zone&#8221; of mandibular molars.Objectives: The aim of this study was to evaluate the effects of a crown-down sequence of Gates-Glidden and TripleGates burs on the remaining cervical dentin thickness and the total amount of dentin removed from the root canals during the instrumentation by using cone beam computed tomography. The number of separated instruments was also evaluated.Material and Methods : Mesial roots of 40 mandibular first molars were divided into 2 equal groups: crown-down sequence of Gates-Glidden (#3, #2, #1) and TripleGates burs. Cervical dentin thickness and canal area were measured before and after instrumentation by using cone beam computed tomography and image analysis software. Student&#8217;s t-test was used to determine significant differences at p<0.05.Results : No significant differences (p>0.05) were observed between the instruments, regarding the root canal area and dentin wall thickness.Conclusion : Both tested instruments used for cervical preparation were safe to be used in the mesial root canal of mandibular molars

The impact of obesity on prostate cancer.

Contains fulltext : 52102.pdf (publisher's version ) (Closed access)Increasing prevalence of obesity in many parts of the world emphasizes the importance of learning more about the relationship between obesity and prostate cancer (PC). The present paper reviews the impact of obesity on PC using knowledge obtained from the available literature. Search of published literature in PUBMED database. Adipose tissue constitutes an active endocrine and metabolic organ which may be relevant in the development and progression of PC by different potential mechanisms. Furthermore, obesity could have an impact on the outcome of different treatment modalities for PC, both functionally as anatomically. Obesity is a growing problem, however, the exact role in the development and progression of PC has not been elucidated. Regarding the optimal treatment of PC in obese patients, comparative prospective studies are needed