Biofilm formation following chitosan-based varnish or chlorhexidine-fluoride varnish application in patients undergoing fixed orthodontic treatment: a double blinded randomised controlled trial.

BACKGROUND: Orthodontic treatment poses an increased risk of plaque accumulation and demineralisation of enamel leading to white spot lesion around the brackets. This parallel arm trial aims to assess the degree of bacterial plaque formation adjacent to orthodontic brackets, following the application of a chitosan-based varnish or chlorhexidene-fluoride varnish. METHODS: A total of 200 teeth from 20 patients undergoing fixed orthodontic therapy were assessed and biofilm formation around the brackets were recorded using the Bonded Bracket Index (Plaque index) at baseline and weekly for 6 weeks. The bacterial count and plaque pH at corresponding weekly intervals were also recorded. Following bracket bonding, the patients were cluster randomised to receive chitosan-based varnish-CHS (UNO Gel Bioschell, Germiphene corp., Brantford, Canada) or chlorhexidine-fluoride varnish-CFV (Cervitec F, Ivoclar Vivadent, Schaan, Liechtenstein) every week on the representative teeth respectively. BBI proportions were compared between groups at all time intervals using Chi square test. Mean plaque bacterial count and plaque pH were compared using Mann Whitney U test and Tukey's HSD test respectively. RESULTS: Baseline characteristics were similar between the groups: Mean age was CHS = 23 and CFV = 21; male to female ratio was CHS = 5/5, CFV = 7/3. At the end of 6 weeks, chitosan-based varnish performed equal to chlorhexidine-fluoride varnish (P > 0.05) with 98% and 95% of teeth with acceptable scores respectively. The plaque bacterial count significantly reduced at 6 weeks for both varnish compared to the baseline; The value for CHS was 0.43 ± 0.4 × 104 and CFV was 0.77 ± 0.64 × 104 CFU (P < 0.05), with no difference between both the varnishes. Both varnishes had no effect on the plaque pH that remained neutral. CONCLUSION: This trial showed that both chitosan-based varnish and chlorhexidine-fluoride varnish reduced bacterial count, while the plaque pH remained neutral over a period of six weeks in patients undergoing fixed orthodontic therapy. The anti-plaque effects of the natural biopolymeric chitosan-based varnish was similar to that of chlorhexidine-fluoride varnish, a known chemotherapeutic agent. Registration: This trial protocol was registered with https://www.ctri.nic.in (CTRI/2019/05/018896). (Date of registration 02/05/2019). PROTOCOL: The protocol was not published before trial commencement.

Palatogingival groove mimicking as a mutilated root fracture in a maxillary lateral incisor: a case report.

This article presents a case of a palatogingival groove (PPG) in tooth No. 12 that was misdiagnosed as a mutilated root fracture. A PPG is a developmental anomaly that predisposes a tooth to a severe periodontal defect. The initial diagnosis of mutilated root fracture on tooth No. 12 was made solely from radiographs that showed a vertical and horizontal radiolucent line with a radiolucent halo-shaped bone resorption in relation to the root apex. Transillumination, bite test, surgical visualization of the site, and the use of high-end diagnostic modalitieswere not considered prior to the final diagnosis. PPG was confirmed only after the tooth was extracted and observed under a dental operating microscope.

Morphologic variations in mandibular premolars: a report of three cases.

AIM: To report cases with morphologic variations in mandibular premolars. BACKGROUND: Mandibular premolars have earned the reputation for having aberrant anatomy. The occurrence of three canals with three separate (type V, Vertucci) foramina in mandibular premolars is very rare. In this report, three cases are presented involving the root canal treatment of mandibular premolars with three different root and canal configurations. The present report also emphasizes the use of the dental operating microscope to enhance visualization. CASE DESCRIPTION: Correlation between radiographic findings, use of dental operating microscope and knowledge of aberrant anatomy helps to identify, locate and treat the aberrant anatomy of the tooth. CLINICAL SIGNIFICANCE: The treatment was successful as all canals were identified and filled and also as evidenced by relief of symptoms. CONCLUSION: Success is largely dependent on the use of magnification, which aided in identifying the location of the three individual root canal orifices; thus emphasizing the need to familiarize ourselves with dental microscopy, to obtain maximal anatomic information in endodontic practice.

Revascularization for a necrotic immature permanent lateral incisor: a case report and literature review.

BACKGROUND: Revascularization is a valuable treatment in immature necrotic teeth that allows the continuation of root development. CASE REPORT: This article describes the successful revascularization treatment of an immature maxillary lateral incisor that was initially diagnosed with apical periodontitis. The tooth was asymptomatic and functional clinically and radiographically during the follow-up period of 5 years. CONCLUSION: The follow-up showed evidence of progressive thickening of the dentinal walls, development of root length and apical closure. The article also discusses the currently available literature regarding revascularization of immature permanent teeth.

Maxillary first molar with three buccal roots evaluated with cone-beam computed tomography: a rare case report.

This case report describes the nonsurgical endodontic management of a maxillary first molar with the unusual morphology of three separate buccal roots. An accurate assessment of this morphology was made with the help of cone-beam computed tomography (CBCT). This report also describes the varied root morphology associated with maxillary first molars and the role of CBCT as a diagnostic tool for managing these complex cases successfully.

Do Calcium Chelators Play a Role in the Removal of Calcium Hydroxide From Root Canals? A Systematic Review of Laboratory Studies.

OBJECTIVE: To identify whether root canal irrigants with calcium chelation ability play a role in the removal of calcium hydroxide (CH) from the root canals when compared to non-chelators. METHODS: The protocol is registered in the Open Science Framework registry (doi 10.17605/OSF.IO/CHG2Q). PubMed, Scopus, Embase, Cochrane Library, ProQuest, Google Scholar, Science direct and open grey databases were searched until March 2021. Laboratory studies comparing the effectiveness of calcium chelators in the removal of CH with non-chelators delivered using needle irrigation, irrigation agitation or instrumentation techniques were included. The quality of included studies was appraised using a modified Joanna Briggs Institute critical appraisal checklist for a randomised clinical trial. Two independent reviewers were involved in study selection, data extraction, appraising the quality of studies. Any disagreements were resolved by a third reviewer. RESULTS: The current review included 17 studies, with 16 being of "moderate" quality and one of "low" quality. Due to methodological differences within the included studies, quantitative analysis was not performed. Laboratory studies were only included in the current review because no clinical study exists on this topic. Evidence from the review indicates that calcium chelators are superior to non-chelators in the removal of CH when used with needle irrigation, passive ultrasonic irrigation and instrumentation techniques. CONCLUSION: Calcium chelators are superior in the removal of CH from the root canal system over non-chelators.

Endodontic management of pulp canal obliteration using a new single-tooth template: A case series.

Background: Guided Endodontics is suggested as a reliable method for management of teeth with pulp canal obliteration (PCO). The guide used for this usually involves multiple teeth to gain stability but is bulky. It is therefore suboptimal to be used along with rubber dam. Aim: To describe the use of a minimized single-tooth guide template in three patients with radiographic evidence of PCO. Design: The template was designed and fabricated using the cone-beam computed tomography (CBCT) scan and a surface scan image of the involved teeth. In all three patients, the root canals were successfully negotiated within 15 minutes, with the template involving only the tooth in focus or with neighboring half of the teeth. The operator stabilized the template if required. Conclusions: This case series shows clinically that successful outcome can be obtained during guided endodontics with the use of a single-tooth template in previously traumatized anterior teeth with PCO.

Evaluation of effect of two different functionalized nanoparticle photodynamic therapy on nanohardness of root dentin-An in vitro study.

INTRODUCTION: The aim of this study was to evaluate the effect of functionalized nanoparticle photodynamic therapy on Nano hardness of root dentin METHODOLOGY: Fifty single rooted lower premolars were decoronated and sectioned into two halves. Then the samples were embedded horizontally in to the acrylic resin to expose the dentin surface. Baseline nanohardness was done at midroot level using a Nanohardness tester. Exposed dentin surfaces were immersed in the following irrigating solutions Post treatment nanohardness testing was done and results were analyzed statistically RESULTS: In general, all the samples in their respective groups had significant change in nanohardness following immersion in irrigant solutions except in NaOCl + EDTA and saline group. CSRB-np and PLGA-MBnp showed increased nanohardness (P = 0.005 and P = 0.007 respectively). Whereas NaOCl + EDTA + CHX showed decrease in nanohardness (P = 0.04). With regards to Modulus of elasticity (MOE), CSRB-np showed significant difference (P = 0.002) compared to the other groups. MOE increased in CSRB-np and PLGA-MBnp while it decreased in all the other groups. CONCLUSION: In this study, the improvement of nanohardness and modulus of elasticity following the immersion of root dentin in CSRB-np solution was demonstrated.

The evaluation of root canal morphology of the mandibular first molar in an Indian population using spiral computed tomography scan: an in vitro study.

In this study, root canal morphology of 125 extracted mandibular first molars from an Indian population was evaluated by using spiral computed tomography (SCT). The results of this study showed that the majority of the teeth samples (84.48%) had the 3 canal (mesiobuccal, mesiolingual, and 1 distal canal) configuration and that the cementoenamel junction coincided with the roof of the pulp chamber in 37.09% of the samples only.

Calcific healing of a crown root fracture of a maxillary central incisor evaluated with spiral computed tomography and hounsfield units: a case report.

Trauma to anterior teeth results in crown root fracture in 5% of cases. Calcific healing of a complicated oblique crown root fracture is rarely reported in literature. This article highlights the calcific healing of a traumatized maxillary central incisor with crown root fracture. This unique observation of healing following trauma was confirmed with the use of spiral computed tomography and Hounsfield units.

Non-metallic grid for radiographic measurement.

The purpose of this paper is to suggest an easier, non-metallic radiographic grid system for measuring the working length and radiographic size of pathologic areas during endodontic diagnosis and prognosis determination.

Evaluation of the pulp chamber size of human maxillary first molars: an institution based in vitro study.

The aim of this in vitro study was to determine the morphological measurements of the pulp chamber and also to establish the relationship of the cemento-enamel junction (CEJ) to the roof of the pulp chamber of the maxillary first molars in an Indian population. One hundred extracted human maxillary first molars were used. Each molar tooth was radiographed by radio visiography (RVG). Measurements were made by using the grid option in RVG. The results (mean +/- SD; in mm) were as follows: distance from floor of the pulp chamber to the furcation = 2.7 +/- 0.63; distance from roof of the pulp chamber to the furcation = 5.34 +/- 0.9; distance from tip of the palatal cusp to the furcation = 11.58 +/- 1.01; distance from the tip of the palatal cusp to the floor of the pulp chamber = 8.86 +/- 0.68; distance from the tip of the palatal cusp to the roof of the pulp chamber = 6.2 +/- 0.66; height of the pulp chamber = 2.62 +/- 0.61. The results of these measurements revealed that the morphological measurements of the maxillary first molars in the Indian population were similar to that reported by previous studies; the roof of the pulp chamber was found at the CEJ in 96% of the specimens.

Removal efficiency of calcium hydroxide intracanal medicament with two calcium chelators: volumetric analysis using spiral CT, an in vitro study.

The vehicles used to carry calcium hydroxide intracanal medicament are many and may affect the retrieval. Access cavities were prepared in 40 single rooted anterior teeth, cleaning and shaping was done and filled with either Metapex or pure calcium hydroxide powder in distilled water. After 7 days the calcium hydroxide was retrieved using either 17% EDTA or 10% citric acid in combination with ultrasonic agitation. Volume analysis was done using spiral computed tomography. The percentage difference was calculated and statistically analyzed using Kruskal-Wallis and Mann-Whitney U test. 10% citric acid showed better removal efficiency than 17% EDTA for Metapex (p = 0.003). The 17% EDTA showed excellent removal efficiency of powder form of calcium hydroxide in distilled water than Metapex (p < 0.001). Ten percent citric acid removed powder form of calcium hydroxide in distilled water better than Metapex (p = 0.05).

Assessment of the role of cross section on fatigue resistance of rotary files when used in reciprocation.

OBJECTIVE: The purpose of this study was to assess the role of cross section on cyclic fatigue resistance of One Shape, Revo-S SU, and Mtwo rotary files in continuous rotation and reciprocating motion in dynamic testing model. MATERIALS AND METHODS: A total of 90 new rotary One Shape, Revo-S SU, and Mtwo files (ISO size 25, taper 0.06, length 25 mm) were subjected to continuous rotation or reciprocating motion. A cyclic fatigue testing device was fabricated with 60° angle of curvature and 5 mm radius. The dynamic testing of these files was performed using an electric motor which permitted the reproduction of pecking motion. All instruments were rotated or reciprocated until fracture occurred. The time taken for each instrument to fracture was recorded. All the fractured files were analyzed under a scanning electron microscope (SEM) to detect the mode of fracture. Statistical analysis was performed using one-way ANOVA, followed by Tukey's honestly significant difference post hoc test. RESULTS: The time taken for instruments in reciprocating motion to fail under cyclic loading was significantly longer when compared with groups in continuous rotary motion. There was a statistically significant difference between Mtwo rotary and the other two groups in both continuous and reciprocating motion. One Shape rotary files recorded significantly longer duration to fracture resistance when compared with Revo-S SU files in both continuous and reciprocating motion. SEM observations showed that the instruments of all groups had undergone a ductile mode of fracture. CONCLUSION: Reciprocating motion improved the cyclic fatigue resistance of all tested groups.

Role of pH Changes on Transforming Growth Factor-ß1 Release and on the Fibrin Architecture of Platelet-rich Fibrin When Layered with Biodentine, Glass Ionomer Cement, and Intermediate Restorative Material.

INTRODUCTION: The purpose of this study was to evaluate the influence of pH that is due to setting reaction of Biodentine, glass ionomer cement (GIC), and intermediate restorative material (IRM) on transforming growth factor-ß1 (TGF-ß1) release and on the fibrin architecture of platelet-rich fibrin (PRF). METHODS: PRF was obtained from 8 volunteers and layered over the freshly prepared GIC, IRM, and Biodentine mixtures. TGF-ß1 release was estimated by using enzyme-linked immunosorbent assay (ELISA), and fibrin structure of PRF was analyzed by using scanning electron microscope at 1 and 5 hours. RESULTS: Biodentine, GIC, and IRM increased the TGF-ß1 release in comparison with that of control group (PRF alone) at both 1 and 5 hours. Biodentine released significantly more TGF-ß1 than GIC and IRM at 1 hour. At 5 hours both GIC and Biodentine released significantly more TGF-ß1 than IRM. The fibrin architecture of the Biodentine group was similar to that of control group at both 1 and 5 hours. In GIC and IRM groups the fibrillar structure of fibrin was collapsed, ill-defined, and cloudy with very thick fibers and irregularly reduced porosities. CONCLUSIONS: Biodentine induces larger amount of TGF-ß1 release and also maintains the integrity of fibrin structure when compared with GIC and IRM when layered over PRF.

Evaluation of penetration depth of 2% chlorhexidine digluconate into root dentinal tubules using confocal laser scanning microscope.

OBJECTIVES: This study evaluated the penetration depth of 2% chlorhexidine digluconate (CHX) into root dentinal tubules and the influence of passive ultrasonic irrigation (PUI) using a confocal laser scanning microscope (CLSM). MATERIALS AND METHODS: Twenty freshly extracted anterior teeth were decoronated and instrumented using Mtwo rotary files up to size 40, 4% taper. The samples were randomly divided into two groups (n = 10), that is, conventional syringe irrigation (CSI) and PUI. CHX was mixed with Rhodamine B dye and was used as the final irrigant. The teeth were sectioned at coronal, middle and apical levels and viewed under CLSM to record the penetration depth of CHX. The data were statistically analyzed using Kruskal-Wallis and Mann-Whitney U tests. RESULTS: The mean penetration depths of 2% CHX in coronal, middle and apical thirds were 138 µm, 80 µm and 44 µm in CSI group, respectively, whereas the mean penetration depths were 209 µm, 138 µm and 72 µm respectively in PUI group. Statistically significant difference was present between CSI group and PUI group at all three levels (p < 0.01 for coronal third and p < 0.001 for middle and apical thirds). On intragroup analysis, both groups showed statistically significant difference among three levels (p < 0.001). CONCLUSIONS: Penetration depth of 2% CHX into root dentinal tubules is deeper in coronal third when compared to middle and apical third. PUI aided in deeper penetration of 2% CHX into dentinal tubules when compared to conventional syringe irrigation at all three levels.

Mandibular first molar with a single root and single canal.

Successful endodontic management of mandibular first molar with a single root and single canal is diagnosed with the aid of dental operating microscope and multiple angled radiographs. In addition all the mandibular molars and premolars were single rooted on either side.

Endodontic management of three-canalled mandibular lateral incisor using dental operating microscope.

This case report presents endodontic management of a mandibular lateral incisor with three canals using surgical dental operating microscope. This study describes the root canal variation of mandibular lateral incisor and highlights the importance of surgical operating microscope in detecting an unusual canal morphology.

Effectiveness of four different final irrigation activation techniques on smear layer removal in curved root canals : a scanning electron microscopy study.

OBJECTIVE: The aim of this study was to assess the efficacy of apical negative pressure (ANP), manual dynamic agitation (MDA), passive ultrasonic irrigation (PUI) and needle irrigation (NI) as final irrigation activation techniques for smear layer removal in curved root canals. MATERIALS AND METHODS: Mesiobuccal root canals of 80 freshly extracted maxillary first molars with curvatures ranging between 25° and 35° were used. A glide path with #08-15 K files was established before cleaning and shaping with Mtwo rotary instruments (VDW, Munich, Germany) up to size 35/0.04 taper. During instrumentation, 1 ml of 2.5% NaOCl was used at each change of file. Samples were divided into 4 equal groups (n=20) according to the final irrigation activation technique: group 1, apical negative pressure (ANP) (EndoVac); group 2, manual dynamic agitation (MDA); group 3, passive ultrasonic irrigation (PUI); and group 4, needle irrigation (NI). Root canals were split longitudinally and subjected to scanning electron microscopy. The presence of smear layer at coronal, middle and apical levels was evaluated by superimposing 300-µm square grid over the obtained photomicrographs using a four-score scale with X1,000 magnification. RESULTS: Amongst all the groups tested, ANP showed the overall best smear layer removal efficacy (p < 0.05). Removal of smear layer was least effective with the NI technique. CONCLUSION: ANP (EndoVac system) can be used as the final irrigation activation technique for effective smear layer removal in curved root canals.