The physical mechanisms of ultrasound, namely cavitation and acoustic streaming, generated by the Enac-Osada ultrasonic unit were investigated for effectiveness in disrupting Streptococcus mitis. In addition, the bactericidal effect of ultrasound in the presence of 2.5% sodium hypochlorite was examined. Bacterial suspensions were irradiated directly with ultrasound in simulated root canals, and the viability of bacteria was examined after growth on a blood agar medium under anaerobic conditions at 37 degrees C for 5 days. The results indicated that ultrasound per se failed to disrupt bacteria but resulted in increases in the viable counts; the former was considered to be because of the lack of cavitation and the latter because of the dispersal effects of acoustic streaming. The 2.5% sodium hypochlorite solution demonstrated powerful bactericidal activity.
The efficacy of two ultrasonic units in shaping curved canals in teeth were compared. Twenty teeth were instrumented using the Cavi-Endo unit at a power setting 1 using the technique recommended by the manufacturer. Another group of 20 teeth received similar treatment but were instrumented with the Enac unit. The time taken to instrument each canal was recorded. The pre- and post-instrumented radiographs of the teeth of x 10 magnification were taken using a microfocal technique. The radiographs were subjected to a subtraction technique to result in composite images of the pre- and post-instrumented shapes. The canal shape and the incidence of elbows were evaluated using various measurements taken from the radiographs. The manner the dentine was removed was similar in both groups. All canals exhibited unequal removal along the canal with more dentine being removed at the coronal end. The Enac group exhibited a higher incidence of elbows which occurred further apically than those in the Cavi-Endo group. There was no significant difference between groups in the following: time of instrumentation, amount of apical and coronal canal enlargement, apical deviation and change in width at the elbow. These findings were no different from those of another study using simulated canals.
Composite resins have been advocated as a reinforcing build-up material for badly damaged endodontically treated teeth with flared canals. However, the control of an autocuring composite resin is difficult because it polymerizes rapidly within the root canal. While the light-curing composite resins are more user friendly, their polymerization can be a problem deep in the root canal. Light-transmitting plastic posts allow the transmission of light into the root canal and enable intraradicular composite resin reconstitution and reinforcement of weakened roots. At the same time, the light-transmitting plastic post forms an optimal post canal in the rehabilitated root and can accurately fit a matching retentive final post. These light-transmitting posts are a useful addition to the dental armamentarium.
In this study, the depth of cure of composite resins cured within simulated root canals by means of light-transmitting plastic posts was compared to that achieved by the conventional light-curing method. Six sizes of posts with diameters of 1.05 mm, 1.20 mm, 1.35 mm, 1.50 mm, 1.65 mm, and 1.80 mm were investigated. In general, the larger the post diameter, the greater was the depth of cure. There were significant differences in the depth of cure between the control and all sizes of posts investigated. There were also significant differences between the various post diameters except for the 1.35 mm and 1.50 mm diameter posts. It was possible to achieve a depth of cure exceeding 11 mm using these light-transmitting posts.
The root canal walls of twenty -five deciduous molar teeth with exposed and necrotic pulps were examined using thescanning electronmicroscope. Immediately after extraction, all teeth were fixed in Kamosky's solution. The coronal portion of the tooth was sectioned at about 2mm above the enamel cemental junction.The mesial and distal roots were separat~d and either split in the mesio-distal or bucco-lingual direction. All specimens were prepared for SEM. Obsevations showed that all roots were infected with organisms consisting of cocciand short rods. Some of the coccihad penetrated the dentine layer. However, the distribution of organisms is. not uniform throughout thecanals. Bacterialinvasion ismostinthecoronal region and reduces towards the apical region: Accompanying bacterial invasion is root canal walls deterioration. The odontoblastic processes are the first to deteriorate followed by the predentine layer.
Simulated canals in clear resin blocks have been widely used in pre-clinical endodontic teaching. The artificial canal provides direct visualisation of procedures in root canal treatment. Stanuardised simulated root canals have been produced in the Faculty of Dentistry, University of Malaya for dental education and research. The canals are easy and inexpensive to construct. An outline of the method of construction of resin simulated canals is presented in this paper.
The cross-sectional canal morphology and minimum widths of buccal and lingual canal walls were studied in 20 mandibular molars with C-shaped roots and canal orifices. The roots were mounted in clear resin blocks and sectioned transversely at 1-mm intervals. A total of 154 cross-sections were evaluated with an image analyzer. Twelve different longitudinal canal configurations were identified. The most prevalent were types 1-2 and 1-2-1 with each type occurring in four roots. Evaluation of the cross-sectional morphology showed that the configurations were complete "C" (27%), incomplete C (64%), and non-C (9%). The mean value for the minimum width of the lingual canal wall was 0.58 +/- 0.21 mm and the buccal wall was 0.96 +/- 0.26 mm. This suggests that there is a higher risk of root perforation at the thinner lingual walls of C-shaped canals during shaping and post canal preparation procedures. Both buccal and lingual canal walls were frequently narrower at mesial locations.
Existing literature suggests a relationship between the amount of remaining tooth structure and the fracture resistance of the restored endodontically treated tooth. This study investigated the amount of tooth structure remaining following various tooth preparations used in the restoration of the endodontically treated maxillary second premolar. Illustrations of the maxillary second premolar in buccopalatal, mesiodistal and occlusal sections were drawn to scale. Outlines of various intra- and extracoronal preparations were superim-posed on the illustrations to reveal the amount of tooth tissue remaining in each case. Preparations for a ceramic inlay, inlay with palatal cusp coverage and onlay left 2.0-2.5mm of tooth structure buccally and palatally. Following preparation for a metal-ceramic crown, approximately 1.0mm of tooth structure remained buccally, and between 1.6mm-1.8mm palatally. Preparation for an all-ceramic crown was observed to leave 1.0mm-1.2mm of tooth structure surrounding what remained of the endodontic access cavity. It was concluded that decisions as to the type of definitive restoration to restore the endodontically treated maxillary second premolar may be influenced, amongst other factors, by information on the amount of tooth tissue remaining following preparation.
Background: Majority of root canal treatment in Malaysia was provided by general dental practitioner. The purpose of this study was to evaluate the knowledge and practice (canal’s preparation, use of materials) by them. Methods: A questionnaire was structured and distributed to 120 registered general dental practitioners in selected areas in Perak, Johor and Klang Valley regarding the provision of root canal therapy in their practices. The questionnaires were hand delivered and collected after 1 to 2 weeks. Results: Reply rate was 95% (n=114). The result demonstrated that 62% respondents indicated that they performed the root canal therapy (RCT) themselves. Out of these only 26% included molars in the treatment. Three quarters of them (77%) used step-back technique and 54% used stainless steel instruments to prepare the canals. The majority of the respondents (69%) used calcium hydroxide as intracanal medicaments. Only 30% used rubber dam for isolation whereas the rest used cotton rolls. The numbers of routine radiographs taken were two for anterior teeth and three for molar. Half of the respondents indicated that they usually completed the RCT for the anterior tooth within two visits whereas three visits were needed for the molar tooth. The results were analyzed descriptively. Conclusions: This study indicates that most of the general dental practitioners’ do not comply with quality standards guidelines such as use of rubber dam as isolation. Cotton roll was the most popular isolation method. In spite of this, most of the respondents tend to update their knowledge and practices with current techniques and materials.
During post crown restoration, the preparation of the post canal can be fraught with difficulties resulting in widening, gouging and transportation of the post canal; sometimes with near root perforation. A technique is described to repair such iatrogenically damaged internal root canal walls using reinforcing resin composite and optic glass fibre posts. The root dentine, resin composite and glass fibres, having similar moduli of elasticity, will result in a repaired root with a ‘monolithic’ structure and possessing numerous desirable characteristics. This repair technique can easily be carried out in one sitting at the chairside thereby allowing the continued serviceability of the iatrogenically compromised root-filled tooth.
Quality radiographs of diagnostic value are important in root canal treatment. The dentist who has knowledge and skills in the use of radiographs for diagnostic purposes has a professional responsibility to ensure that the radiographs are obtained with minimum risk of radiation dose to and for the benefit of the patient. This article reviews the effectiveness of radiography techniques required for successful root canal treatment with the patient’s interest in mind. Awareness of effectual radiographic techniques, their constraints and applicable techniques for improvements are discussed. It seeks to reduce potentially harmful ionising radiation dose to patients and optimise the use of X-rays to produce diagnostic radiographs during root canal treatment.
The aim of the present study was to assess the current approaches and philosophies pertaining to direct restorations, bleaching and root canal treatment amongst general dental practitioners (GDPs) in the Klang Valley, Malaysia. A questionnaire, together with a stamped addressed envelope and an explanatory letter, was sent to 200 GDPs in the Klang Valley in April-July 2005. The GDPs were selected at random. A total of 153 (76.5%) of the GDPs responded to the survey. 46.4% of the respondents stated that the use of amalgam was decreasing whereas 79.7% stated an increase in the use of composite resins. Clinical indication (85.6%) and patients’ demand for aesthetics (73.9%) appeared to be the main factors influencing the choice of restorative materials. Fractured restorations was the main reason for the replacement of amalgam restorations (77.1%) whilst secondary caries was the main reason for the replacement of composite resin restorations (73.9%). Almost two thirds of the GDPs surveyed provided chair side bleaching while 75.8% of the GDPs would supervise home bleaching. Sodium hypochlorite was the most common endodontic irrigant used amongst the GDPs surveyed and cold lateral compaction was the most commonly used obturation technique.
Introduction: Preclinical teaching using simulation is very beneficial in training dental graduates. The use of laboratory simulation for its undergraduate training during the preclinical years has been used in dental education. Purpose: The aim of this study was to evaluate student’s perception, self evaluation and satisfactory level in preparing duralay burn-out post and core in preclinical fixed prosthodontics sessions.
Materials and Methods: The participants comprised of 104 fourth year dental undergraduates in the Faculty of Dentistry Universiti Kebangsaan Malaysia. The students had undergone preclinical session for endodontics during the 3rd year and had already completed root canal treatment on single rooted tooth. The same tooth was used for preclinical post and core preparation. The gutta percha was partially removed and the root canal was prepared. They then proceeded with the preparation of duralay build-up/pattern based on the lecture, video demonstration and manual given. Once completed and satisfied with their work, students were asked to answer the questionnaires in the simulation manual.
Results: Student response rate was 88.46% (92/104). Majority of the students were satisfied with their canal preparation, with about 5mm gutta percha left apically, appropriately shaped canal with sufficient retention and resistance form. They also thought that the surface of the duralay was good with no voids. With regards to the coronal preparation, majority of them incorporated ferrule effect and prepared preliminary crown preparation. More than half of the students claimed the level of difficulty of this procedure was moderate. Furthermore, majority of them said that the lecture and the preclinical manual were sufficient and helpful. The help from the supervisors was also benefit in preparing duralay burnout post and core.
Conclusions: From this study, majority of fourth year dental students could perform appropriate canal preparation as well as duralay pattern post and core. Only one student did not feel competent and confident in doing canal preparation and duralay pattern post and core. Our teaching methods and aids were proven to help them in preparing these tasks.
Aim: To manufacture a clinical simulation apparatus for the undergraduates' endodontic radiography teaching Objectives: • To provide a model for teaching of parallax method using Kelly's forcep • To provide a model for undergraduates to practice radiographic localization employing parallax method. • To allow students to practice taking radiographs in a way that simulates the clinical situations with a good diagnostic quality Methods: Impressions of a dentate arch (maxillary and mandibullary) were used to form a stone cast. A section of the cast, in the area where the natural teeth were to be placed, is sectioned and removed. Three maxillary extracted teeth (canine, first and second premolar) were selected and mounted with acrylic resin at the sectioned area. The resin was cured in a light box. The arches were mounted in a phantom head with a placement of rubber cheek. The first premolar was isolated with rubber dam. The intraoral holder (Kelly's forcep) was attached to a robotic arm. The students were taught the correct angulations of the x-ray cone for the paralleling technique and parallax method using Kelly's forcep during root canal treatment. Results: All students managed to complete the exercise and were considered competent when they produced acceptable quality of radiographs. Conclusion: The model described was improvised from a model that has been used during the past 2 years for undergraduates' endodontic courses. It has been well accepted as it simulates the clinical situation more closely than was possible previously.
Root canal treatment (RCT) requires high level of technical skills of the dentist. Its outcome is an important part of evidence-based practice and become the basis of treatment planning and prognostic considerations. Adequate removal of micro-organisms and prevention of recolonization of residual micro-organisms through the placement of root filling with satisfactory coronal seal ensures success. This retrospective record review study aimed to investigate the practices of RCT in Hospital Universiti Sains Malaysia (HUSM) Dental Clinic, Kota Bharu, Kelantan. It involved 333 randomly selected patient records at the HUSM Record Unit. Data was obtained by careful analyses of daily treatment progress sheets and analyzed using SPSS version 12.0. A total of 2996 RCT cases were seen and 59.8% of patients were females. The age range of patients varied from 14 to 64 years. The maxillary anterior teeth were most commonly treated (52.6%). Most operators (99.1%) used step-back technique and 97.6% used files to prepare root canals. The most commonly used material for obturation and sealing was gutta-percha and epoxy resin-based sealer (AH26). About 82.9% used calcium hydroxide as intra-canal medication. About 25.5% of cases had no periapical pathology, 65.8% with pre-existing periapical radiolucencies healed in 1-3 months whereas 2.1% of cases with periapical pathology eventually healed after a year. About 6.9% cases failed after retreatment. The number of radiographs taken was two to four pieces. RCT is a useful intervention to maintain longevity of teeth. Decision making and current updates of methods and materials are essential among practitioners as well as administrators to ensure success.
The objective of this study was to investigate the effect of various luting cement systems on bond strength of fibre-reinforced posts to root canal dentine. 40 extracted single rooted sound premolar teeth were root filled, decoronated and randomly divided into four groups. Fibre posts, Aestheti- Plus™ (Bisco,Inc. Schaumburg, IL, USA) were cemented using four luting cements: Group A (control): Elite 100® Zinc phosphate (GC Corp, Japan), Group B: Calibra ™ Esthetic Resin Cement (Dentsply Caulk, USA), Group C: RelyX ARC Adhesive Resin (3M ESPE), Group D: RelyX Unicem Aplicap (3M ESPE). Each root was sliced into 2 discs representing the coronal and middle portions of the root canal giving rise to 20 specimens per group. Bond strength was determined using push-out tests and data was analyzed using SPSS version 14.0. The mean bond strength of Group A to Aestheti-Plus™ post was 7.71 MPa (±2.51) and Group B was 5.69 MPa (±3.23). Group C exhibited the lowest mean bond strength, 4.29 MPa (±3.53) while the highest bond strength was obtained from Group D, 7.98 MPa (±2.61). One way ANOVA showed significant interaction between all groups (p=.OOI). Post-hoc Bonferroni test reve;iled that bond strength of Group C was significantly lower compared to Group A (p=.008) and D (p=.004). In conclusion, the mean bond strength of Aestheti- Plus™ post to root canal dentine was highest when cemented with RelyX Unicem resin cement followed by Elite 100® zinc phosphate cement, Calibra and RelyX ARC resin cements. However, the bond strengths of Cali bra and RelyX Unicem resin cements were not significantly different from Elite 100® zinc phosphate cement.
The main objective of a root end filling material is to provide an apical seal that prevents the movement of bacteria and the diffusion of bacterial products from the root canal system into periapical tissues. The aim of this study was to compare the microleakage of three root end filling materials Mineral trioxide aggregate (MTA), Glass ionomer cement (GIC) and Silver GIC (Miracle Mix) using dye penetration technique under stereomicroscope. Forty-five extracted human maxillary central incisors were instrumented and obturated with gutta percha using lateral compaction technique. Following this, the teeth were stored in saline. After one week, teeth were apically resected at an angle of 90ï° to the long axis of the root and root end cavities were prepared. The teeth were divided into three groups of fifteen specimens each and were filled with Group I -MTA, Group II - GIC and Group III - Miracle Mix. The samples were coated with varnish and after drying, they were immersed in 1% methylene blue dye for 72 hours. The teeth were then rinsed, sectioned longitudinally and observed under stereomicroscope. The depth of dye penetration was measured in millimeters. Microleakage was found to be significantly less in MTA (0.83 mm) when compared to GIC (1.32 mm) (p < 0.001) and with Miracle Mix (1.39 mm) (p < 0.001) No significant difference was found when microleakage in Miracle Mix was compared to that of GIC (p = 0.752). Thus we concluded that MTA is a better material as root end filling material to prevent microleakage, in comparison to GIC and Miracle Mix.
This study aimed to detect the presence of enterococci in the root canals of untreated and treated teeth with periapical disease and to compare this to their presence in the saliva and in the immediate surgical environment during root canal treatment. Using an aseptic technique, 33 samples were obtained from 27 untreated and 6 previously treated teeth associated with apical periodontitis. Reduced Transport Fluid (RTF) was used as transport medium. Saliva samples and areas in the surgical environment were also sampled. These were performed prior to chemo-mechanical debrjdement and obturation for every case. The saliva was diluted to 10- J and was plated on Bile Aesculin Azide (BEA) agar whereas the rest of the samples were plated on Bile Aesculin (BE) agar. These plates were then incubated aerobically at 37°C for 48 hours. All the colony types that blackened the agar were sub-cultured to obtain pure isolates and tested on 6.5% sodium chloride (NaCI). Growth on this medium was Gram stained for further confirmation of cell morphology. Gram positive cocci isolated from previous positive test were identified as enterococci. Enterococci were recovered from untreated cases only; from 2 teeth (in 2 patients) prior to chemo-mechanical debridement, from 3 teeth (in 3 patients) prior to obturation and I from saliva sample. A 'total of 5 samples from 5 different patients were positive for enteroco•cci. Sampling in the immediate surgical environment revealed a low occurence in the range of3.0% (1/33) to 15_2% (5/33). In conclusion, the occurence of enterococci in patients and the immediate surgical environment was low number.
The objectives of this study were to assess the practice of molar root canal treatment (RCT) among general dental practitioners (GDPs), confidence level of GDPs in performing molar RCT and to identify factors that influence their confidence in managing molar RCI. One hundred questionnaires were distributed to GDPs in Kuala Lumpur and Selangor. Fifty questionnaires were delivered by mail and the remaining fifty were hand-delivered. All data was coded and verified. Fiftysix OOPs rcsponded to the questionnaires. Only fortyfive questionnaires were accepted (n=45) as eleven OOPs had never performed molar RCI. Most of the OOPs followed the standard quality guidelines while performing molar RCT except for vitality testing (36.4%) and rubber dam usage (27.3%). In this study, 100% of the GDPs were confident in making diagnosis of perinidicular diseases and 95.4% were confident in performing molar RCT from history taking until obturation. Patients' tolerance and availability of instruments and materials (97.7%) were two factors that most influence the GDPs' confidence level. The. least influcncing factor was undergraduate training (78.1 %). Attending seminars and lectures on endodontic, large number of molar teeth treated for ReT, patLents' affordability to pay for RCT and postgraduate training also influencc GDPs' confidence to a certain degree. From this study, it can be concluded that majority of OOPs complied standard quality guidelines except for vitality testing and rubber dam usage. Most of them were confident in performing molar RCT and were greatly influenced by the availability or"instruments and materials in their clinic and patients' tolerance in receiving molar RCI.
Tissue regeneration is a rapidly growing field providing a beacon of hope in the field of restorative and endodontics. Root canal treatment involves the removal of pulp tissue and replacement by an inorganic materials where as regenerative endodontics deals with replacement with healthy pulp to revitalize the teeth .Research in the field of tissue engineering and material science have lead to significant progress but still is plague with lots of drawbacks and failures, hence it is still not being adapted as routine clinical procedures .The purpose of this article is to review the advances made in regenerative endodontics and the future scopes.