in-vitro evaluation of microleakage at the cervical margin between two different class ii restorative techniques using dye penetration method

Objective: To evaluate the coronal microleakage of packable composite using conventional incremental and posterior bulk fill flowable composite using Smart Dentine Replacement Single Step technique in the cervical margins of class II cavities in dentine using the dye penetration method

Study Design: In-vitro Interventional study

Place and Duration of Study: Department of Operative Dentistry, Dr. Ishrat-ul-Ebad Khan Institute of Oral Health Sciences [DIKIOHS], Karachi, from November 2012 to April 2013

Methodology: One hundred and twenty extracted teeth [molars and premolars] were collected and randomly divided into two experimental groups [n=60 each] and were stored in normal saline until used. Fractured samples were excluded. Standardized class II proximal box only cavities were prepared and restored with conventional methacrylate based composite using incremental technique [Group A, n=40] and low stress methacrylate resin based composite SDR using single step technique [Group B, n=40]. Samples were sectioned horizontally below the cervical margins and specimen disks were prepared. The specimens were thermocycled and sealed with acid resistant varnish leaving a 1-mm interface around cervical margin and immersed in 2% methylene blue buffered solution for 24 hours. Leakage was scored 0 - 4 and measured in mm. It washed and sectioned to evaluate under stereomicroscope

Results: Mean penetration was 2.4280 +/-0.79 mm for Group A and 1.015 +/-0.45 mm for Group B [p < 0.001]. Maximum dye penetration score for group A was 4 and group B was 3

Conclusion: SDR technique in combination with total etch technique at the cervical margin of class II restorations improved the marginal seal, when were placed in dentine and thermocycled

Micromechanical intervention in sandwich restoration

Objective: To evaluate the sealing ability of two different types of Glass Ionomer Cements [GICs] used for sandwich restorations and assess the effect of acid etching of GIC on microleakage at GIC-resin composite interface

Study Design: Experimental study

Place and Duration of Study: Department of Operative, DIEKIOHS [DUHS] and NED University, Karachi, from February to June 2011

Methodology: Eighty cavities were prepared on the proximal surfaces of 40 permanent human premolars [2 cavities per tooth], assigned to 4 groups [n=20] and restored as follows: Group CIE - Conventional GIC [CI] was applied onto the axial and cervical cavity walls, allowed setting for 5 minutes and acid etched [E] along the cavity margins with 37% phosphoric acid for 15 seconds, washed for 30 seconds and dried; the adhesive system was applied and light cured for 10 seconds, completing the restoration with composite resin light cured for 40 seconds; Group CIN - same as Group CIE, except for acid etching of the CI surface; Group RME - same as CIE, but using a resin modified GIC [RMGIC]; Group RMN - same as Group RME, except for acid etching of the RMGIC surface. Specimens were soaked in 1% methylene blue dye solution at 37[degree]C for 24 hours, rinsed under running water for 15 minutes, bisected mesiodistally and dye penetration was measured following the ISO/TS 11405-2003 standard. Kruskal Wallis and post Hoc tests significant differences in the microleakage among all the four groups

Results: There was a significant difference between the two groups of GICs [RMGIC and CI, p=0.001]. There was no significant difference in between the two sub-groups that is between CIN and CIE [p=0.656], and between Groups RME and RMN [p=0.995]

Conclusion: Phosphoric acid etching of GIC, prior to the placement of composite resin, does not improve the sealing ability of sandwich restorations. RMGIC was more effective in preventing dye penetration at the GIC-resin composite dentine interfaces than CI

Knowledge about the management of avulsed toothamong Karachi school teachers

The objective of this study was to assess the knowledge of school teachers regarding management of avulsed tooth. The information about the management of avulsed tooth was collected through a specifically designed questionnaire. A total of 150 questionnaires were distributed among teachers of five different private schools of Karachi who were dealing with children of 6 to 12 years old. Out of 150 teachers only 100 answered the questionnaire [66%]. Majority [80%] of the teachers knew about the importance of emergency management of tooth avulsions. One third [34%] teachers answered affirmative regarding their experience with tooth avulsions. 26% said that they would replant the avulsed tooth by themselves. More than half [57%] of the teachers, preferred water as the best storage medium than normal saline. Knowledge of school teachers regarding management of avulsed tooth was unsatisfactory. It should be improved by continuous dental educational seminars in schools

Effect of different irradiation times on microhardness and depth of cure of a nanocomposite resin

To determine the microhardness and depth of cure of nanocomposite using different irradiation times on both upper and lower surfaces of composite material. In-vitro experimental study design. Dr. Ishrat-ul-Ebad Khan Institute of Oral Health Sciences, Dow University of Health Sciences and NED University of Engineering and Technology, Karachi, from March to May 2010. Total 120 cylinder shaped specimens; 60 specimens for depth of cure test and 60 specimens for micro hardness test were fabricated using A3 shade of nanocomposite [Filtek Z350 XT, 3M ESPE]. For each irradiation time four groups were made [Group 1 = 20s] [Group 2 = 30s], [Group 3 = 40s] and [Group 4 = 60s]. For each group fifteen specimens were used. The resin was placed and polymerized into a cylindrical plastic mold. Depth of cure was measured by using micrometer. Micro Vickers hardness was measured on both top and bottom surfaces. SPSS-16.0 was used for statistical analysis. There was statistically significant difference in the depth of cure between all groups showing the highest value in group 4 [p < 0.001]. For hardness on top surface, there was a statistically significant difference in between groups 1 and 2 [p=0.001], groups 1 and 3 [p < 0.001], groups 1 and 4 [p < 0.001] There was no statistically significant difference between groups 2 and 3, groups 2 and 4 and in between groups 3 and 4. For hardness on bottom surface, there was statistically significant difference in between all groups showing the highest value in group 4 [p < 0.001]. Depth of cure and hardness was increased by increasing irradiation time. Hardness on the top surface was higher than bottom surface values

Acquaintance of dental professionals in relation to emergency management of tooth avulsion in Karachi

Avulsion of permanent tooth is the most serious of all dental injuries. The prognosis depends on the measures taken at the place of accident or the time immediately after the avulsion. An appropriate emergency management and treatment plan is important for a good prognosis. The objective of the present study was to evaluate and investigate the knowledge of dental professionals about the emergency management of tooth avulsion in Karachi. Two hundred questionnaires were distributed amongst General dental practitioner, Postgraduate trainees and house officers, the questions were related to knowledge of how to treat and manage the traumatic avulsion of teeth. Out of 200 dentists targeted 50% were involved in Continuing Education Programme 25% updated their knowledge through journals and books. While rest had only information they got during their education at dental schools. The data suggested that the level of knowledge on the management of dental avulsion among dental professional in city of Karachi is adequate

Unusual rootless eruption of a permanent maxillary central incisor: a case report

This report presents a case of rootless eruption of permanent central incisor following an intrusion injury to the primary teeth

comparison of thermomechanical compaction and cold lateral condensation obturation techniques on the basis of density measurements, using digital radiographs

To compare the cold lateral condensation and the thermomechnical condensation obturation techniques by measuring the radiographic density of the obturation. Digital radiographs were used as an aid for the comparison. A total of 100 single rooted teeth mainly central incisors were divided into two groups. Group A comprised of teeth that were obturated using cold lateral condensation and Group B comprised of teeth that were obturated using thermomechanical technique. The canals of all the teeth were prepared with rotary endodontics [Protaper System] with a working distance of 21mm. During the sample preparations irrigation with EDTA was used to remove the smear layer. One group of teeth was obturated with ISO standardized gutta percha points using cold lateral condensation and the other group was obturated using thermomechanical technique [Gutta Condensors-Dentsply]. Digital radiographs were taken processed in Digora System for both the techniques. The apical area was zoomed to 4x and density measurement readings for both the techniques were recorded and compared using Digora Optime. The mean for Group A was found to be 140 while for Group B the value was 136. The difference was statistically significant [p < 0.005]. The study concluded that both the techniques are acceptable clinically. However the cold lateral condensation technique was found to be superior to thermomechanical compaction in terms of radiographic density

Incidence of three canals in maxillary first premolar-a case report

This paper reports successful endodontic treatment of a maxillary first premolar with three canals. Maxillary premolars have highly variable root canal morphology, but it is rare, especially in the first premolar, to find three canals. However, in everyday endodontic practice, clinicians have to treat teeth with atypical configurations. Extra roots or root canals if not detected are a major reason for failure. Systematic examination of preoperative X-rays and correct access. Ni-Ti rotary instrumentation technique was chosen for root canal preparation, and Canals were obturated with gutta percha cones [Sure-Endo, Seoul, Korea] and Sealapex [Ken, Sybron, USA] root canal sealer using cold lateral condensation filling technique This methology led to efficient preparation and suitable definitive root canal obturation