Radiographic technical quality of root canal treatment performed ex vivo by dental students at Valencia University Medical and Dental School, Spain.

OBJECTIVES: To evaluate radiographically the quality of root canal fillings and compare manual and rotary preparation performed on extracted teeth by undergraduate dental students. STUDY DESIGN: A total of 561 premolars and molars extracted teeth were prepared using nickel-titanium rotary files or manual instrumentation and filled with gutta-percha using a cold lateral condensation technique, by 4th grade undergraduate students. Periapical radiographs were used to assess the technical quality of the root canal filling, evaluating three variables: length, density and taper. These data were recorded, scored and used to study the "technical success rate" and the "overall score". The length of each root canal filling was classified as acceptable, short and overfilled, based on their relationship with the radiographic apex. Density and taper of filling were evaluated based on the presence of voids and the uniform tapering of the filling, respectively. Statistical analysis was used to evaluate the quality of root canal treatment, considering p < 0.05 as a statistical significant level. RESULTS: The percentage of technical success was 44% and the overall score was 7.8 out of 10. Technical success and overall score were greater with rotary instruments (52% against 28% with a manual one, p < 0.001; 8.3 against 6.7 respectively, p < 0.001). CONCLUSIONS: It appears that inexperienced operators perform better root canal treatment (RCT) with the use of rotary instrumentation.

Traumatic dental injuries among schoolchildren in Valencia, Spain.

AIM: The aim of the present study was to identify some factors related to the occurrence of dental trauma in mixed and permanent dentition. DESIGN OF THE STUDY: Over a period of two months 1325, 6 to 18 year olds from three primary schools in Valencia were examined. Data was collected through clinical examinations and interviews and their Dental trauma was classified according to IADT's criteria. RESULTS: The prevalence of dental injuries was 6%; boys aged between 12-18 years old experienced more injuries than girls. There was a statistical difference between the types of fractures. Non complicated coronal fractures were the most frequent (9.18%). Games were the main cause of trauma (40%) in both sexes. In 14.3% of patients a dental colour change was observed. Angle's class I was the most frequent in traumatized injured children (41.2%). CONCLUSIONS: The present study revealed a relatively low prevalence of dental trauma, but this figure still represents a large number of children. Therefore, educational programs are to be initiated for the community regarding causes , prevention and treatments of traumatic dental injuries.

Bleaching in vital teeth: Combined treatment vs in-office treatment.

BACKGROUND: The aim of this study was to verify that there will be greater whitening in teeth treated with combined bleaching than in those that have been applied a clinical one and to evaluate the efficiency of the clinical treatment, those cases in which it is not able, or it is not wanted, to carry out the home phase. MATERIAL AND METHODS: They were used 66 extracted anterior human teeth, which were divided into two study groups. On the one hand, the clinical group (ClG) consisted of 33 teeth, which were treated with a clinical guideline using 37.5% hydrogen peroxide in a single session of 4 applications of 8 minutes. On the other hand, the combinate group (CoG) consisted of 33 teeth, which were treated with a combined guideline, applying first a clinical treatment as in the ClG and, at home treatment with carbamide peroxide at 16% for 22 days, 90 minutes a day. The colour of the tooth was measured before and after each treatment and was made through an individualized whitening splint with a spectrophotometer. RESULTS: The 66 teeth were bleached, showing an increase in luminosity, a drecrease in yellow and a shift towards the green colours, where b (yellow-blue axis) was the only variable with a statistically significant change (p<0.001). The CoG obtained a significantly higher absolute value (p<0.001) than the ClG, being 12.99 for the first one and 19.70 for the second one. CONCLUSIONS: Combined therapy bleached more than clinical one, but both techniques were effective. In addition, it is affirmed that the clinical could be an alternative in those cases in which it is not able, or it is not wanted, to carry out the home phase. Key words:Carbamide peroxide, CIELab, combined guidelines, dental bleaching, hydrogen peroxide.

Dentinal sensitivity: concept and methodology for its objective evaluation.

Dentinal sensitivity is a clinical condition of some importance, particularly in periodontal patients. Symptoms appear on applying a triggering stimulus to the exposed dentine - the particularity being that the pain is similar to that of other dental disorders of different etiology and treatment. Hence the importance of a correct differential diagnosis. The main problem not only in clinical practice when treating the disorder, but also in designing studies for the objective evaluation of dentinal sensitivity, is the difficulty of standardizing, evaluating and interpreting the clinical condition in its different degrees. Thus, consensus in designing and evaluating studies of dentinal sensitivity would facilitate our understanding of its etiology, and the assessment of possible treatments. Such studies may center their methodology on individual patient response or on the nature of the triggering stimulus. The present study provides an updated and global view of the disorder, and reviews the basic protocol for the objective assessment of dentinal sensitivity.

An in vitro cyclic fatigue resistance comparison of conventional and new generation nickel-titanium rotary files.

BACKGROUND: New designs and processing of Niquel-Titanium (NiTi) have been introduced to increase resistance to cyclic fatigue. The purpose of this study was to compare the cyclic fatigue resistance of 3 NiTi rotary instruments, ProTaper Next (PTN; Dentsply Maillefer, Ballaigues, Switzerland), Profile Vortex Blue (PVB; Dentsply Tulsa Dental, Tulsa, OK, USA) and ProTaper Universal (PTU; Dentsply Maillefer, Ballaigues, Switzerland). MATERIAL AND METHODS: A cyclic fatigue test was conducted operating instruments from ProTaper Next X2, Profile Vortex Blue 25.06 and ProTaper F2. A total of 234 instruments were rotated in 2 simulated stainless steel curved canals with different angles of curvature (45º and 60°) and 5-mm radius of curvature. The number of cycles to fracture (NCF) was calculated. Data were compared using 2-way analysis of variance and post-hoc Bonferroni test in software (SPSS 15.0, Chicago, IL). Statistical significance was set at P<0.05. RESULTS: Profile Vortex Blue showed higher resistance to cyclic fatigue in both curved canals than ProTaper Next and ProTaper Universal (P<0.001). ProTaper Universal obtained the lowest resistance to cyclic fatigue in both canals (P<0.001). CONCLUSIONS: Profile Vortex Blue was the most resistant to cyclic fatigue failure, followed by ProTaper Next and ProTaper Universal. Anatomical complexity (angle of curvature) and manufacturing process of NiTi are important factors for resistance to cyclic fatigue. Key words:Cyclic fatigue, M-Wire, Protaper Next, ProTaper Universal, Profile Vortex Blue.