Evaluation of antimicrobial and thermal effects of diode laser on root canal dentin.

OBJECTIVES: The aim of this study was to evaluate the antimicrobial effects of diode laser and temperature rise on the root surface during application. MATERIALS AND METHODS: Thirty-six teeth were chemomechanically prepared and irrigated with 2.5% sodium hypochlorite and 17% ethylenediaminetetraacetic acid, and then autoclaved and incubated with a suspension of Enterococcus faecalis. The specimens were randomly divided into three groups (n = 12): Group 1, irradiated by diode laser at 1.2 W; Group 2, irradiated by diode laser at 2 W; and Group 3, irradiated by diode laser at 3 W. The grown bacteria were counted and the mean numbers of the each test tube were determined. The temperature was measured on the external apical third of the root during laser application. The mean values of results for each group were compared using one-way analysis of variance and Tukey test. RESULTS: No significant difference was obtained among the test groups in terms of the colony counts (P > 0.05). According to the temperature changes, there was a significant difference between groups (P < 0.05). Temperature rises were 16.79°C, 10.20°C, and 6.25°C in Group 3, Group 2, and Group 1, respectively. CONCLUSION: Diode laser irradiation with 1.2 W demonstrated comparable performance with 2 W and 3 W power sets for elimination of E. faecalis from root canal with less temperature rise.

Effect of several thermoplastic canal filling techniques on surface temperature rise on roots with simulated internal resorption cavities: an infrared thermographic analysis.

AIM: To evaluate the surface temperature rise using an infrared thermal imaging camera on roots with and without simulated internal resorption cavities, during canal filling with injectable (Obtura II), carrier-based (Soft-Core) gutta-percha and continuous wave of condensation (System B) techniques. METHODOLOGY: Root canals of 60 mandibular premolar teeth were instrumented to an apical size of 40. Circular artificial internal resorption cavities with a diameter of 2.40 mm were prepared on the root canal walls of 30 teeth. All teeth were divided into six groups of 10 specimen and root filled as follows: group 1 (teeth with internal resorption): thermoplasticized injectable gutta-percha (Obtura II), group 2 (teeth without internal resorption): thermoplasticized injectable gutta-percha (Obtura II), group 3 (teeth with internal resorption): carrier-based gutta-percha (Soft-Core), group 4 (teeth without internal resorption): carrier-based gutta-percha (Soft-Core), group 5 (teeth with internal resorption): continuous wave of condensation (System B) and group 6 (teeth without internal resorption): continuous wave of condensation (System B). The surface temperature changes during filling of canals were measured with an infrared thermal imaging camera. The thermograms were recorded at 2-s intervals over a period of 40 s to determine the maximum temperature rise at the apical, middle and cervical thirds of the root surface. The data were statistically analysed with one-way anova and Tukey HSD post hoc or Kruskal-Wallis and Bonferroni-adjusted Mann-Whitney U-tests if appropriate. RESULTS: The temperature rise on the surface of roots with artificial resorptive defects was significantly higher compared with the ones without defects in the Obtura II and System B groups (P < 0.001). The System B group with internal resorption was associated with the maximum temperature rise in the apical (4.3 ± 2.1) and middle (19.5 ± 8.9) thirds amongst the groups (P < 0.001). CONCLUSION: Use of System B and Obtura II for filling canals with internal resorptive cavities resulted in surface temperature rise over the critical threshold. However, Soft-Core root filling did not increase the temperature over 10 °C.

Radiculomegaly of permanent canines: report of endodontic treatment in OFCD syndrome.

AIM: To present a case describing the endodontic treatment of a permanent canine with radiculomegaly and to draw the attention of the endodontic community to this rare anomaly. SUMMARY: Oculo-facio-cardio-dental (OFCD) syndrome is a rare X-linked dominant syndrome characterized by canine teeth with extremely large roots (radiculomegaly), dental abnormalities, congenital cataracts, dysmorphic facial features and congenital heart disease. The diagnosis of this syndrome is difficult. Unique and specific symptoms, which can be diagnosed by an endodontist or a general dentist, are present in the dental, skeletal, ocular and cardiac structures. Worldwide, only 20 cases of this syndrome have been reported to date. The patient presented in this study was a 17-years-old girl with a mandibular right canine (47.5mm) tooth with two canals. KEY LEARNING POINTS: • Clinicians should be aware of anatomical variations in cases with OFCD syndrome. • Root canal treatment in such cases is challenging. • In general, the majority of mandibular canines have one root and root canal, but 15% may have two canals, and a smaller number may have two distinct roots.

Fracture resistance of thin-walled roots restored with different post systems.

AIM: To compare the fracture resistance of thin-walled roots after restoration with different types of post systems. METHODOLOGY: One hundred and sixty-five decoronated maxillary central incisors were root filled and randomly assigned to three groups with respect to the remaining dentine thickness of root (1.0 mm, 1.5 mm, 2.0 mm). Each group was randomly divided into five equal subgroups. The subgroups were restored with one of the following post systems: polyethylene woven fibre (R), composite resin cured by light-transmitting post + glass fibre post (L), electrical glass fibre post (E), composite corono-radicular restoration (C) and cast metal post (M). Standard cores were constructed using composite resin in the first four groups. The samples were subjected to a gradually increasing force (1 mm min(-1)). The force required to fracture was recorded. The data was analysed with anova and Tukey test (P = 0.05). RESULTS: The cast metal post group had the highest fracture strength (P < 0.001). There was no significant difference in fracture resistance between the other four groups. Fracture resistance was affected largely by the remaining dentine thickness in fibre post groups; however, the difference was not significant. On the contrary in the cast metal post group load failure was inversely influenced by axio-proximal dimension of dentine walls. CONCLUSION: The cast post group had a higher fracture strength than resin groups. The force required to fracture the roots was similar for all fibre post systems and for all dentine thicknesses.

Lactate dehydrogenase activity in periodontal ligament cells stored in different transport media.

BACKGROUND: Maintaining viability of periodontal ligament cells is important after an avulsion injury occurs. OBJECTIVE: This study examined cell death and compared different transport media at varying times. Lactate dehydrogenase (LD) measurements were made on root surfaces of extracted teeth for evaluating the results of breakdown and necrosis of periodontal ligament cells. STUDY DESIGN: Teeth were divided into three groups. Each was immersed in one of the following storage media: Hanks balanced salt solution, Custodiol solution (an organ storage medium), or sterile saline solution. I.D. measurements (an indicator of cell death) were made at 2, 6, 24, 72, and 168 hours after extraction. RESULTS: When the LD levels were compared according to the time periods, a progressive increase of cell death was found to be statistically significant (p < 0.001). However, when the effects of both time periods and the kind of storage medium on the LD levels were examined, the LD levels of the saline solution storage medium were found to be significantly higher (p < 0.001) than that of the other two groups. CONCLUSIONS: Both Hanks balanced salt solution and Custodiol appeared to be suitable transport media for maintaining cell viability, whereas saline solution was not.

Evaluation of coronal microleakage of four different glass-ionomer cements in endodontically treated teeth.

Four different glass-ionomer materials were evaluated for coronal microleakage in permanent lingual access restorations of endodontically treated anterior teeth. Forty extracted human anterior teeth were randomly divided into four groups following chemomechanical preparations and obturations with gutta-percha and sealer. Logobond, Aqua Ionobond, Ionoseal and Ketac-Cem were placed in 2 mm thickness over the gutta-percha obturation from cemento-enamel junction. Eight teeth were used as negative and positive controls. The teeth were thermocycled, coated with nail varnish and paraffin except around the access preparation. Next they were placed in dye and cleared to allow visualization of dye penetration. There was a tendency for the Ketac-Cem group to lack least but there were no statistically differences among the groups.

Comparison of the sealing efficacies of two obturation techniques in curved root canals instrumented with and without ultrasonic irrigation.

Volumetric dye penetration into the canals of 131 teeth was studied spectrophotometrically. The teeth were first divided into three groups according to the degree of curvature. Each group was then subdivided into four groups, in which the Thermafil and lateral condensation techniques were used with or without ultrasonic irrigation. Significant microleakage differences were observed between group I (0-10 degrees) and group III (21-30 degrees) for lateral condensation filling with ultrasound irrigation and Thermafil filling without ultrasound irrigation (p < 0.05).

Cytotoxicity versus antibacterial activity of some antiseptics in vitro.

Through the development of new techniques for bacterial growth and isolation, obligate anaerobes have been shown to be more prevalent than previously thought in the pathogenesis of periapical and pulpal diseases. A follow-up study was conducted to examine the germicidal effect of 0.05% NaOCl, 10 mg/ml metronidazole and supernatant of Ca (OH)2 (0.025 ml) on four anaerobic microorganisms commonly found in root canals, and to compare the toxicity of these substances on cell cultures. In vitro testing revealed that 0.05% NaOCl and Ca (OH)2 were both equally effective on these anaerobes. Also, metronidazole was found to be germicidally effective against Bacteroides melaninogenicus, Bacteroides oralis and Peptostreptococcus anaerobius, but ineffective against Veillonella alcalescens. Furthermore, it was found that NaOCl and Ca (OH)2 had a very destructive effect on cell cultures compared with their antimicrobial effect, whereas metronidazole was less toxic among the agents tested.

Evaluation of diagnostic radiopaque contrast materials used with calcium hydroxide.

An evaluation of three different radiopaque materials used in combination with calcium hydroxide powder for diagnostic contrast was made. Diatrizoate meglumine (65%) and iothalamate meglumine (60%) compared favorably with barium sulfate (35%). Since barium sulfate has demonstrated problems by altering the manipulative properties of calcium hydroxide as well as demonstrating a residual radiopacity, there may be advantages to the use of resorbable diatrizoate or iothalamate compounds as alternatives. These soluble iodine compounds also make possible an excellent aqueous medium in which to mix calcium hydroxide.

[An evaluation of the antibacterial effectiveness of bisdequalinium acetate and sodium hypochlorite]. / Bis-deqalinium asetat ve sodyum hipoklorid solusyonlarinin antibakteriyel etkinliklerinin degerlendirilmesi.

The antimicrobial effectiveness of sodium hypochlorite and bis-dequalinium acetate was evaluated in vitro using three different microorganisms. The solutions were prepared in various concentrations and microorganisms were exposed to these solutions for 5, 10, 15 min. then placed into a culture medium, incubated and determined the presence or absence of growth. These results were compared with those obtained with phenol. The following conclusions were drawn from this study: 1. Of the solutions tested Bis-dequalinium acetate was the most effective antimicrobial agent. And 1.25/1000 Bis-dequalinium acetate is appropriate for the clinical use. 2. Sodium Hypochlorite is the least effective compared with Bis-dequalinium acetate and phenol. 2/100 NaOCl is agreeable for the clinical use. 3. Normal saline exhibits no antimicrobial properties.