Radiographic and electronic working length comparison. An in vivo study of three Electronic Apex Locator devices.

The aim of this study is to compare the working length measured with Root ZX (EAL1), Propex II (EAL2) and Endo Analyzer Model 8005 (EAL3) with radiographic measurements during endodontic treatment. Fifty single canal teeth scheduled for endodontic treatment were selected for the study. After endodontic access preparation, pulp chamber was irrigated with 5mL of 5% sodium hypochlorite (NaOCl). The canal was scouted with a size 10 K-file introduced slightly over the apex to verify the canal patency. The working length (WL) was measured using all three EAL devices and radiographically. All measured working lengths were recorded and compared using ANOVA for repeated measures considering the multiple comparison of paired data Least Significant Difference (LSD). The WL mean values for EAL1 were 19.1 ± 1.7 mm; for EAL2 were 19.4 ± 1.7; for EAL3 were 19.4 ± 1.6 and for RG were 19.2 ± 1.7. The Pearson correlation coefficients indicated that the following correlation between electronic devices and radiographic WL: EAL1- 0.986, EAL2- 0.953 and EAL3- 0.931. Considering the mean values compared to radiographic measures, Root ZX gave better results than the other tested EAL devices. Endo Analyzer Model 8005 showed the worst performance.

Microbial leakage evaluation of warm gutta - percha techniques.

The aim of this study is to compare bacterial leakage of MicroHeat and continuous wave with and without endodontic sealer. Thirty-eight single-rooted extracted mandibular premolars were selected and randomly divided into four experimental groups (n=8) and two control groups (n=3). Teeth were prepared with Mtwo NiTi files and obturated with MicroHeat or System B with or without endodontic sealer. Three teeth were used as positive controls (Ct+) and three intact teeth served as negative controls (Ct-). All samples were tested for bacterial infiltration every day for 60 days. On day 32 overall contamination value was 62.5% for Mseal, 75% for Mnoseal, 75% for SBseal and 37.8% for SBnoseal; after 60 days, the final contamination result was 100% for Mseal, Mnoseal and SBseal and 87.5% for SBnoseal. At the end of the observation period, groups showed no statistically significant differences.

Reduction of radiations exposure in endodontics: comparative analysis of direct (GX S-700, Gendex) and semidirect (VistaScan Mini View, Dürr) digital systems.

The importance of intraoral periapical radiography is crucial as it represents a fundamental mean of evaluation and diagnosis for supporting bone and teeth hard tissues diseases and pathologies. Even though conventional film technology is still widespread, presently there are many digital radiography alternatives. Direct digital systems are devices with an intraoral sensor wired or paired wireless with a computer. These devices do generate an image immediately during exposure and acquisition. The semi direct digital systems instead are based on phosphor image plates. Digital radiography offers many chances to improve our patient's healthcare standards reducing exposition to X-rays and the related stochastic radiation risk. Aim of this study is to compare the quality of images for endodontic purposes comparing three systems: conventional films, direct digital radiography and semidirect digital radiography.

Antibacterial activity of first and latest generation bioceramic sealers on the elimination of enterococcus faecalis: An in vitro study.

The main concern of endodontics are bacteria: the microorganisms and the toxins they release determine tissue destruction and inflammatory changes that trigger the pulpal and periapical pathology. Enterococcus faecalis is a particularly hostile bacterium; it is strongly associated with refractory periapical pathology. In this study 3 materials were tested: Aureoseal (OGNA, Italy) (Aur) (first generation bioceramic sealer); Endo Seuqence BC sealer (Brasseler USA, Savannah, GA, USA) (EsBC) (latest generation bioceramic sealer); Endoidrox (OGNA, Italy) (Endx) (calcium hydroxide material). The antimicrobial activity of these materials against Enterococcus faecalis was evaluated using agar diffusion test (ADT). The results confirm the antibacterial activity of bioceramic sealers, which however do not show significant differences in the obtained values; it can therefore be concluded that there has been no increase in the antibacterial efficacy of the latest generation bioceramic sealers compared to those of the first generation.

Dentinal substrate variability and bonding effectiveness: SEM investigation.

Though the literature reports a well-documented scientific evidence of the performance of modern adhesive systems on normal dentin, few researches are available on the interaction between adhesives and compromised dentin. In this study, the authors analyzed the microscopic structural aspects of the adhesive interface on two common altered dentin substrates: dentin contaminated by metallic oxides and caries affected dentin. Thirty teeth were selected and divided in three groups of ten teeth according to the different dentin substrate they had: (A) normal dentin, (B) caries-affected dentin and (C) dentin contaminated by metallic oxides. The experimental cavity preparation was realised exposing in each sample, portion of pathologic dentin and portion of sound dentin as control. Each cavity was restored with micro-hybrid composite, with total etching and a two-step adhesive system. Each sample was sectioned in two halves analysed with two SEM micro-morphological methods: direct observation and decalcification. SEM investigations were able to show the difference in thickness and morphology of the adhesive interface with the two different dentin variables. Caries affected dentin determined the formation of less distinctive resin tags with few micro-tags. Discoloured dentin showed a poor infiltration with few resin tags probably due to alterations in the tubular structures. The micro-morphological variability of dentin substrate influences the clinical efficacy of bonding restorations determining significant differences in the qualitative and quantitative aspects of resin tags.

Comparative analysis of cleaning ability of two rotary instrument systems: Mtwo and ProTaper® universal. An in vitro scanning electron microscopic study.

This study is to compare the cleaning effectiveness of two Ni-Ti files systems. Thirty single-rooted human teeth were selected and two NiTi rotary systems were used. Group A: canal shaping with ProTaper® Universal (Dentsply Tulsa Dental Specialties, Tulsa, OK) (PTU); Group B: (n=15) canal shaping with Mtwo Ni-Ti instruments (Sweden and Martina, Padova, Italy) and apical finishing with Mtwo Apical Ni-Ti instruments (Sweden and Martina, Padova, Italy). The amount of debris and smear layer were quantified on a basis of a numerical evaluation scale. The data established for scoring the debris and the smear layer was recorded separately and statistically analysed using the Kruskal-Wallis test. No significant differences were found for debris. Mtwo instruments resulted in significantly less smear layer (P less than 0.05) compared with ProTaper® Universal. Under the conditions of this study, Mtwo resulted in significantly less smear layer compared with canal preparation with ProTaper® Universal.

Clinical antibacterial effectiveness Healozone Technology after incomplete caries removal.

AIM: Aim of this study was to evaluate the local effects of ozone gas on bacteria present within deep carious lesions after selective caries excavation. MATERIALS AND METHODS: The present study included 75 patients who had at least two Class I caries with deep lesion D2 and/or D3. The cavities were divided into 2 groups: the ozone group received treatment with Healozone X4, while the control group did not receive any treatment. Dentin samples were taken from both groups using two sterile multi-blade drills at 800 rpm without irrigation. The drills were then stored in separate tubes, each containing 5ml of RTF (Reduced Transport Fluid) and placed in culture for the next two hours. A total microbial count of the CFU of Streptococcus Mutans and Lactobacillus was performed. CONCLUSIONS: From the analysis of data on the dentin samples treated with ozone, there is a decrease in the bacterial load present in the infected carious dentin.

External Cervical Resorption: a case report.

AIM: External cervical resorption is a form of root resorption which begins in the cervical region of the tooth and spreads out in the thickness of the dentin in an irregular way; clinically, it may be not visible and, as it is generally asymptomatic before involvement of the pulp, it is often an occasional finding in radiographic examination. Several factors are related to its aetiology. This paper reports a case of external cervical resorption in a mandibular right first molar of a 17-year-old patient; the tooth was extracted and histological analysis was performed. MATERIALS AND METHODS: Radiographic examination showed a progressive external cervical resorption of the lower right first molar; extension of the lesion and pulp involvement indicated tooth extraction; the sample underwent histological analysis. RESULTS: The histological study confirmed the presence of vascular connective tissue in the resorptive lacunae, invading the dentin from the external surface of the root, and perforations from the defect into the pulp; it was also noticed the presence of bone-like tissue.