Resistance to fracture of teeth instrumented using novel EndoStar E5 rotary versus ProTaper NEXT and WaveOne file systems.

AIM: The current study compared the fracture resistance of samples instrumented by two rotary files and a reciprocating file, obturated with gutta-percha and AH Plus. MATERIALS AND METHODS: A total of 60 freshly extracted mandibular premolar teeth with single roots and single canals were acquired and decoronated at or below the cementoenamel junction. The samples were randomly divided into four groups (n = 15). Group 1 control (noninstrumented/obturated), and for Groups 2-4 root canal instrumentation was done by EndoStar E5 (EE5), ProTaper NEXT (PTN), and WaveOne, respectively. Following instrumentation, the samples were obturated using gutta-percha cones and AH Plus sealer using lateral compaction. A week later, vertical load was applied to the specimen's canal in each group until fracture. The loads required for fracture were recorded and statistically analyzed. RESULTS: The mean loads required to fracture (Newton; N) for the four groups were; 388.54 (±29.93), 310.35 (±26.05), 328.40 (±20.67), and 278.54 (±34.16). The loads exhibited highly significant difference (P < 0.0001; analysis variance). The following Tukey's post hoc test confirmed, both samples in Groups 2 and 3 required similar loads for fracture (P > 0.05) and significantly higher than Group 4 (P < 0.01). CONCLUSION: The samples instrumented by EE5 and PTN exhibit similar fracture resistance.

The self-adjusting file instrumentation results in less debris extrusion apically when compared to WaveOne and ProTaper NEXT.

AIM: The present ex vivo study aimed to evaluate the debris extrusion after instrumenting the root canals by three different files systems. MATERIALS AND METHODS: Sixty extracted human mandibular premolars with single canals were selected and randomly divided into three groups (n = 20) for instrumentation with three different files. Group 1: WaveOne (primary) single reciprocating file (WO; Dentsply Maillefer, Ballaigues, Switzerland) (25/08), Group 2: Self-adjusting file (SAF; ReDent-Nova, Ra'anana, Israel) (1.5 mm), and Group 3: ProTaper NEXT X1 and X2 (PTN; Dentsply Tulsa Dental, Tulsa, OK) (25/06). Debris extruding by instrumentation were collected into pre-weighed Eppendorf tubes. These tubes were then stored in an incubator at 70°C for 5 days. The tubes were then weighed to obtain the final weight, with the extruded debris. Statistical analysis for the debris extruded apically was performed using one-way analysis of variance and post hoc Tukey's test. RESULTS: The statistical analysis showed a significant difference between all the three groups tested (P < 0.01). The following post hoc Tukey's test confirmed that Group 2 (SAF) exhibited significantly least (P < 0.01) debris extrusion between the three groups tested. CONCLUSIONS: The SAF resulted in significantly less extrusion of debris when compared to reciprocating WO and rotary PTN.

Meant to make a difference, the clinical experience of minimally invasive endodontics with the self-adjusting file system in India.

The vital steps in any endodontic treatment are thorough mechanical shaping and chemical cleaning followed by obtaining a fluid tight impervious seal by an inert obturating material. For the past two decades, introduction and use of rotary nickel-titanium (Ni-Ti) files have changed our concepts of endodontic treatment from conventional to contemporary. They have reported good success rates, but still have many drawbacks. The Self-Adjusting File (SAF) introduces a new era in endodontics by performing the vital steps of shaping and cleaning simultaneously. The SAF is a hollow file in design that adapts itself three-dimensionally to the root canal and is a single file system, made up of Ni-Ti lattice. The case series presented in the paper report the clinical experience, while treating primary endodontic cases with the SAF system in India.

Comparative evaluation of root canal disinfection by conventional method and laser: an in vivo study.

OBJECTIVE: The aim of this study was to comparatively evaluate in vivo the disinfecting ability of conventional method and lasers in root canals. MATERIALS AND METHODS: Study criteria included 60 single rooted teeth, which were indicated for root canal therapy followed to dental caries and trauma with intact crowns. Such selected patients were randomly divided into 2 groups, namely, Group A (30 teeth) and Group B (30 teeth). All clinical procedures were carried out under strict aseptic precautions. The teeth in Group A were subjected to biomechanical preparation followed by the treatment with the help of diode laser containing the gallium aluminum and arsenic, which emitted 980 nm wavelengths. The teeth in Group B were treated with routine method of biomechanical preparation along with irrigation using sodium hypochlorite and hydrogen peroxide. The microbiological samples were taken immediately after the access preparation and after the completion of the root canal disinfection and were sent for microbiological analysis. RESULTS: The teeth in Group A showed presence of common strains of bacteria ranging from Streptococci, Staphylococci, Klebsiella, and Pseudomonas. Reduction in the growth of microorganisms was found for all types of microorganisms. Only 8 samples exhibited the growth after treatment with laser. Results of Group B also showed the presence of common strains of anaerobic and aerobic bacteria as shown in earlier studies, predominantly Staphylococcus, Streptococci, and Pseudomonas. Statistical analysis showed non-significant P values for the microorganisms; however, only 3 samples showed the growth after treatment with conventional technique using sodium hypochlorite and hydrogen peroxide. CONCLUSION: Conventional method by using sodium hypochlorite and hydrogen peroxide as irrigating solutions is highly effective in disinfecting the root canal. Lasers when used can also reduce the bacterial load of the infected root canal.

Histological evaluation to study the effects of dental amalgam and composite restoration on human dental pulp: an in vivo study.

OBJECTIVE: To study and compare the effects of dental amalgam and composite restorations on human dental pulp. MATERIALS AND METHODS: One hundred sound premolars scheduled for orthodontic extraction were divided equally into two groups: group A, teeth restored with silver amalgam, and group B, teeth restored with composite resin. Each group was equally subdivided into two subgroups [extracted after 24 h (A-1 and B-1) or 7 days (A-2 and B-2)], and the histological changes in the pulp related to the two different materials at the two different intervals were studied. RESULTS: It was found that after 24 h, the inflammatory response of the pulp in teeth restored with amalgam and composite was similar (p = 1.00). However, after 7 days, the severity of the inflammatory response of the pulp in teeth restored with amalgam was less compared to that in teeth restored with composite (p = 0.045). CONCLUSION: This study confirmed that amalgam continues to be the mechanically as well as biologically more competent restorative material. Composite could be a promising restorative material to satisfy esthetic needs for a considerable period of time. However, its biological acceptance is still in doubt.