Repair bond strength of aged resin composite using different surface treatments and bonding protocols

Background: Repair of direct composites are less invasive than replacement, diminishing the risk of iatrogenic exposure of the pulp and the risk of detrimental to adjacent teeth, all in all, reducing the procession of the “restoration death spiral”. Aim: This study aimed to evaluate the repair bond strength of aged resin composites using different surface treatments and bonding protocols. Materials and Methods: A total of 45 discs (n=45) were fabricated of Nanohybrid composite measuring about 2.5 mm in height and 3.5 mm in diameter and were mounted in acrylic resin and subjected to 10,000 thermal cycles between 5-55 ? C with 30 seconds of dwell time in a thermocycler in order to simulate artificial ageing. All these samples were assigned into three groups (n=15) based on the surface treatment protocol. According to the bonding protocol, the samples in each group are further divided into three subgroups (n=5). After surface treatments of the aged composites, the application of bonding agent followed by new composite material was performed. All the samples were stored in distilled water at 37 ? C for 24 hours. The shear bond strength of the samples was measured using a universal testing machine at a crosshead speed of 1mm/min. Results: Among the groups, the mean bond strength in medium grain diamond bur and 37% phosphoric acid etchant with the universal bonding agent subgroup was higher 852.56±27.71 than the remaining groups. The lowest mean bond strength of 200.9±10.62 was observed in 37% Etchant with direct composite subgroup. Conclusion: Different combinations of surface treatments and bonding protocols affect shear bond strength differently. The highest shear bond strength values were achieved for the group where surface treatment was done with the combination of blue diamond bur and 37% phosphoric acid along with a universal bonding agent

A case of unusual root morphology: Maxillary canine with two roots

The case describes a 3 months follow-up of the treatment of a maxillary canine with two roots. Clinical examination revealed a maxillary canine with a large carious lesion and an exaggerated response to cold thermal tests. Radiographic examination revealed a large distal carious lesion that appeared to invade the pulp chamber. The radiograph also revealed what appeared to be an extra root in this permanent maxillary canine

Maxillary canine with two root canals

To report a rare case of maxillary canine with two root canals. The case describes the treatment of a maxillary canine with two root canals which was referred from department of prosthodontia for intentional root canal treatment for prosthetic rehabilitation. Clinical examination revealed a maxillary canine with carious lesion and responded within normal limits to electric pulp test. Radiographic examination revealed a distal carious lesion (close proximity to pulp) and also appeared to be an additional canal in this permanent maxillary canine

Endodontic retreatment - unusual anatomy of a maxillary second and mandibular first premolar: Report of two cases

An accurate diagnosis of the morphology of the root canal system is a prerequisite for successful root canal treatment. A major cause of endodontic treatment failure in missed (or) untreated root canals is that they still harbor infection. Careful radiographic interpretation and examination of pulp chamber floors are helpful in locating root canal entrances. These case reports present anatomical variations in upper and lower premolars

A novel technique for removal of broken instrument from root canal in mandibular second molar

The fracture of an endodontic instrument is an obstacle in completion of a routine successful pulp space therapy. Ni-Ti instruments corrode when in contact with sodium hypochlorite which leads to their deterioration and ultimately fracture during use. Removal of separated instrument from root canal is often a very difficult procedure. This procedure is more complicated when the instrument separated is closer to the mandibular canal. A case is presented in which a separated hand instrument was retrieved from the mesio buccal of a second molar approximating the mandibular canal root by replantation

An in vitro comparative evaluation of the antibacterial efficacy of 10% metronidazole gel, 2% chlorhexidine gel, and a combination of calcium hydroxide and 2% chlorhexidine gel against Enterococcus faecalis

Background and Objectives: A major objective in endodontic therapy is to disinfect the root canal system prior to obturation. This is because the residual root canal infection can sustain persistent or recurrent periapical disease. Hence, the use of an intracanal medicament between appointments helps in the elimination of bacteria that remain even after cleaning and shaping. The objective of this in vitro study is to compare the antibacterial efficacy of 10% metronidazole gel, 2% chlorhexidine (CHX) gel, and a combination of calcium hydroxide and 2% CHX gel against Enterococcus faecalis (E. faecalis) using a culture technique. Materials and Methods: The study included 40 single-rooted, human permanent teeth, -extracted for periodontal or other reasons. Conventional access to the root canals was obtained using access preparation burs in a high speed handpiece. The working length was determined using the Ingle′s radiographic method and the canals were instrumented using a Step-back technique with K-files, up to size 40, at the apex and irrigated with 1 ml of 2.5% Sodium hypochlorite and Ethylenediaminetetraacetic acid gel. The root canals were filled with a sterile Casein Soya meal peptone solution (CSL) and autoclaved twice for 30 minutes at 121°C. An inoculum of E. faecalis was injected into the canals using a sterile syringe and it was incubated aerobically at 37°C for nine days. The specimens were then randomly divided into three experimental groups (10% metronidazole gel, 2% CHX gel, and a combination of calcium hydroxide and 2% CHX gel) and one control group, each containing 10 samples. Following this, the canals were cleaned using an ultrasonically activated No.15 K-file, along with sodium -hypochlorite irrigation. After medicament removal, each root canal was prepared manually with a new size 40 hedstrom file. The colony forming units per millimeter were determined by the standard laboratory methods. The obtained data was subjected to statistical analysis using the Mann-Whitney test and the χ2 test. Results: In our study, Group II (2% CHX gel) showed significant reduction of E. faecalis. Group I (10% metronidazole gel) showed minimal -reduction, and Group III (2% CHX gel with calcium hydroxide) showed moderate -reduction. There was no -reduction in observed in Group IV (control group) patients. Conclusion: Our study -signifies that 2% CHX gel showed substantial antimicrobial activity against E. faecalis. The -combination of calcium hydroxide and 2% CHX gel also showed good -antimicrobial activity. Hence, the efficacy of 2% CHX gel was greater than its -combination with -calcium hydroxide. The least effective drug against the microbes was metronidazole