Median Perforating Canal in Human Mandible.

Surgical interventions in the anterior region of the human mandible are associated with many complications. Some anatomical structures like the median perforating canal were discovered in mammals. Such canals may be a cause of concern that needs attention in human mandible. The purpose of the present study was to evaluate the occurrence, location, and course of median perforating canal and its associated extensions in the anterior segment of the human mandible in cone beam computed tomography scans (CBCT). Data were collected from 160 CBCT scans, and evaluated. The incidence was 23.75% for median perforating canal with wide anatomical variations concerning the related lingual and labial extensions. Median perforating canal and their associated lingual and labial foramina are frequently seen in human mandible. A thorough investigation of the symphyseal region using CBCT must be taken into account when targeting surgical intervention in this area.

WITHDRAWN: Effect of post space conditioning and luting resin on the retentive strength of fiber-reinforced composite resin posts.

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The Impact of Different Irrigation Regimens on the Chemical Structure and Cleanliness of Root Canal Dentin.

Introduction: This in vitro study aimed to evaluate the effect of different irrigation regimens on the chemical composition and cleanliness of root canal dentin. Materials and Methods: Forty-eight extracted single-rooted permanent human teeth were collected. Root canals were instrumented using step-back technique up to master apical file size 60. Samples were divided into 3 groups (n=16) based on the type of the irrigant used. The irrigation solutions were 5.25% sodium hypochlorite, 2% chlorhexidine gluconate, and saline solution as a control. Root canal cleanliness was assessed using stereomicroscope and scanning electron microscope. Scanning electron microscope energy dispersive X-ray was used for the inorganic analysis. Fourier transform infrared spectrometer was used for the organic analysis. One-way analysis of variance (ANOVA) and multiple comparison post hoc test were used for comparison between the three groups. Results: The highest mean percentage of remaining debris was in saline group followed by chlorhexidine gluconate group. Sodium hypochlorite group showed the lowest mean value of remaining debris. Furthermore, our results showed that canal irrigation with sodium hypochlorite affected the chemical structure of root canal dentin more than chlorhexidine gluconate. Conclusions: Based on the results, 5.25% sodium hypochlorite emerges as the preferred irrigant for root canal treatment. This research sheds light on the significance of irrigation regimens in endodontics and emphasizes the need for careful consideration of irrigant selection in clinical practice.

Dentin wettability enhancement for three irrigating solutions and their effect on push out bond strength of gutta percha / AH Plus.

BACKGROUND: The aim of this study was to investigate the effect of wettability enhancement for 17% EDTA, 2.5% sodium hypochlorite and 7% maleic acid solutions on push out bond strength of gutta percha /AH Plus to root dentin. MATERIAL AND METHODS: One hundred and eight extracted single rooted human lower premolars were instrumented up to Protaper Universal F5 then irrigated with 3ml of 2.5% NaOCl after each file. Irrigants were prepared and a pilot study for determination of Tween 80 concentration yielding the lowest surface tension value in every solution was conducted. Samples were randomly divided into a control group and two experimental groups (17% EDTA and 7% Maleate), further split into eight subgroups (n=12), according to Tween 80 implementation sequence. Roots were obturated using gutta percha and AH plus by lateral condensation. Bond strength was measured by push out test. Mode of failure was then evaluated quantitatively by stereomicroscopy. Data were statistically analyzed using one way ANOVA followed by Tukey-Kramer for multiple comparisons. RESULTS: Control group showed the lowest values. Maleic acid subgroups showed significantly higher overall values than EDTA subgroups (P<0.05). Protocols implementing surfactant containing NaOCl showed significantly lower values than plain counterparts. Failure pattern was predominantly cohesive for plain regimens and the ones implementing Tween 80 in maleic acid solutions with plain NaOCl. CONCLUSIONS: Tween 80 addition to demineralizing irrigants increased the bond strength values. Surfactant containing NaOCl solutions yielded lower bond strength than plain ones. Key words:Wettability enhancement for three irrigants vs. corresponding gutta percha/AH Plus bonding.