Three-Dimensional tooth models for better teaching and treatment outcomes.

INTRODUCTION: The aim of this study was to fabricate 3-Dimensional (3D) tooth models to overcome procedural errors that occur during treatment and to improve endodontic management of teeth with complex pulp morphology and dental anomalies. MATERIALS AND METHODS: Three natural teeth were used to fabricate resinous tooth models (n = 90) and 90 natural teeth were used during root canal treatment. Models were fabricated from 1 mandibular canine (n = 30) and 2 maxillary molars (n = 60). Natural teeth were 30 mandibular canines, 30 mandibular molars and 30 maxillary molars. RESULTS: Natural teeth and opaque resin models were significantly better than the clear resin models during access preparation (p = .003). In addition, the clear resin models were significantly better than the natural teeth and opaque resin models during shaping, obturation and as an educational tool (p < .001, p < .001 and p < .001 respectively). CONCLUSIONS: Although it takes more time and effort to produce 3D (3D) tooth models from each natural tooth used in the study, it can give more accurate results during evaluation.

The antibacterial effect and the incidence of post-operative pain after the application of nano-based intracanal medications during endodontic retreatment: a randomized controlled clinical trial.

OBJECTIVE: This clinical trial aimed to evaluate the effect of nano-silver and nano-calcium hydroxide intracanal medicaments (ICM) during retreatment regarding their antibacterial effect and their effect on post-operative pain and flare-ups. MATERIALS AND METHODS: Sixty-nine patients scheduled for endodontic retreatment were included in this randomized clinical trial and randomly allocated to 3 equal groups (n = 23) according to the type of ICM used. The first microbial sampling (S1) representing the original microbiota was obtained after the removal of the old canal filling. After chemo-mechanical debridement, another sample (S2) was obtained representing the microbial state before ICM application. Patients were randomly allocated to receive either nano-silver (nano-Ag), nano-calcium hydroxide (nano-CH), or calcium hydroxide (CH) as ICM. Patients rated their pain pre-operatively and then after 6, 12, 24, 48, and 72 h. During the second visit (7 days later), the last microbial sample (S3) was obtained after removal of the ICM. Reduction of total bacterial and total E. faecalis counts and the biofilm-forming capability of the existing microbiota were determined. RESULTS: Results showed reduction in total bacterial count, total E. faecalis count and the biofilm-forming,capability of the existing microbiota after chemo-mechanical debridement (S1-S2) and after the application of ICM (S3-S2). However, the reduction after cleaning and shaping was significantly more pronounced (p < 0.001) compared to the effect of ICM application, with no difference between the 3 ICM (p > 0.05). Post-operative pain was significantly reduced at the 48- and 72-h intervals after the application of nano-Ag and nano-CH only (p < 0.001), with no significant difference between these two ICM (p > 0.05). The incidence of flare-ups in all groups was similar (p > 0.05). CONCLUSIONS: The antibacterial effect of the nano-Ag and nano-CH was equivalent to that of CH, but they contributed to better pain control. CLINICAL RELEVANCE: Nanoparticles may have a positive impact on post-endodontic pain.

The effect of changing apical foramen diameter on regenerative potential of mature teeth with necrotic pulp and apical periodontitis.

OBJECTIVE: The aim of the present study was to evaluate the regenerative potential of permanent necrotic mature teeth with different apical foramen diameters in comparison to conventional endodontic treatment. METHODS: Pulp necrosis and periapical pathosis were induced in premolars (144 roots) in six mongrel dogs. The infected teeth were divided into six groups; conventional root canal treatment (RCT) group prepared up to apical preparation sizes #F3 ProTaper file, regenerative endodontic therapy (RET) groups; groups RET-F3, RET-F4, and RET-F5 where regenerative endodontic procedures were applied after apical preparation up to sizes #F3, F4, and F5 ProTaper file, respectively, control groups; and positive (P) and negative (N) groups included infected and healthy teeth respectively. Each group (12 teeth with 24 roots each) was further subdivided into two subgroups (6 teeth with 12 roots each) according to the evaluation periods 1 and 3 months; each group was equally randomized in the upper and lower jaws during each evaluation period. RESULTS: The inflammatory cell counts for the RCT group were statistically significantly higher than that of all RET groups at the first period and only significantly higher than RET-F5 at the second period. The enlargement of the apical foramen to #F5 showed no statistically significant difference with #F4 regarding the inflammatory cell count, tissue in-growth inside the root canal, and percentage of bone resorption. The tissue formed after RET was not true pulp tissue and is considered tissue repair with connective tissue, dilated blood vessels, and cementum-like structures.  CONCLUSION: Increasing the apical size diameter was associated with less inflammatory cell count, less percentage of bone resorption, more tissue ingrowth, and more percentage of new hard tissue formation inside root canal. The minimum apical diameter that should be enlarged for RET is 0.4 mm. CLINICAL RELEVANCE: RET could be used as an alternative procedure to RCT for the treatment of mature teeth with necrotic pulp and apical periodontitis.

Investigation of the regenerative potential of necrotic mature teeth following different revascularisation protocols.

This study aimed to assess the revascularisation potential of necrotic mature teeth in a dog model following different protocols. Periapical infection was induced in 54 mature premolars. Teeth were distributed into seven groups: (1) Double-antibiotic-paste/Blood clot, (2) Ciprofloxacin/collagen, (3) Double-antibiotic-paste/Collagen, (4) Modified Tri-antibiotic-paste /collagen, (5) Ciprofloxacin/Gelfoam, (6) Double-antibiotic-paste/Gelfoam, and (7) Modified Triantibiotic- paste/Gelfoam. Positive and negative controls included infected and healthy teeth, respectively, (n = 12 roots/group). Canals were apically shaped to size 0.6 mm then disinfected for 1 month. Intra-canal bleeding was induced then scaffolds were applied for another month. Teeth and supporting bone were surgically sampled. Tissues were histologically scored and vimentin immuno-intensity was estimated. Ciprofloxacin and Double-antibiotic paste/Collagen resulted in significantly better corono-apical tissue ingrowths, vascularity, cementum formation and significantly lower inflammatory extents (P < 0.05).These groups also showed significantly higher Vimentin intensities, (P < 0.05). The applied protocols revascularised necrotic mature canals and reduced inflammation particularly in the Ciprofloxacin/collagen and Double-antibiotic-paste/collagen groups.

Evaluation of Root and Canal Morphology of Maxillary Permanent Molars in an Egyptian Population by Cone-beam Computed Tomography.

INTRODUCTION: The purpose of this study was to evaluate the number of roots and canal morphology of maxillary permanent molars in an Egyptian population. METHODS: Six hundred fifty-seven cases were included in this study. Digitized images from cone-beam computed tomographic scanning were assessed by 2 endodontists. The number of roots and canal configuration according to Vertucci were tabulated. Age, sex, and bilateral distribution differences were calculated. RESULTS: All maxillary first molars showed 3-root configuration, whereas maxillary second molars showed 3-, 2-, and single-root configurations. For maxillary first molars, the most common Vertucci classifications for the mesiobuccal root were type II (2-1, 45.6%), type IV (2-2, 27.27%), and type I (1, 25.45%). For maxillary second molars, the most common Vertucci classifications for the mesiobuccal root were type II (2-1, 47.1%), type I (1, 42.06%), and type IV (2-2, 8.03%). The prevalence of a second mesiobuccal canal is statistically not affected by either sex, tooth position (right or left side), or age. CONCLUSIONS: Under the conditions of this study, the root canal configurations of an Egyptian population showed that the most common Vertucci classifications for the mesiobuccal root for maxillary first molars were type II (2-1), type IV (2-2), and type I (1). For maxillary second molars, the most common types were type II (2-1), type I (1), and type IV (2-2). Pre-evaluation of the endodontic case using cone-beam computed tomographic digital imaging provides better information of root canal morphology, which might improve the management and prognosis of the case.

Influence of Age and Apical Diameter on the Success of Endodontic Regeneration Procedures.

INTRODUCTION: Treatment of immature permanent teeth with necrotic pulp and apical pathosis constitutes a challenge for endodontists. The present study was done to evaluate the effect of age and apical diameter on the regenerative potential of young permanent immature teeth with necrotic pulps. METHODS: Immature necrotic permanent maxillary incisors (n = 40) of patients 9-18 years old were divided into 2 groups according to the treatment protocol: group Y (younger age group), 9-13 years and group O (older age group), 14-18 years. Each group was further subdivided into 2 subgroups according to apical diameter, subgroup (n) (narrower diameter) between 0.5 and 1 mm and subgroup (w) (wider diameter) equal to or greater than 1 mm. Revascularization procedures were performed for all patients. Follow-up was done for up to 12 months. Standardized radiographs were digitally evaluated for increase in root length and thickness and decrease in apical diameter. RESULTS: After the follow-up period, most of the cases demonstrated radiographic evidence of periapical healing. Group Y showed significant progressive increase in root length and width and decrease in apical diameter. Subgroup (w) representing wider apical diameter showed significant progress as well. CONCLUSIONS: It was found that revascularization procedures can be implemented in any age ranging from 9 to 18 years; however, younger age groups were better candidates for revascularization procedure than older ones. Regarding the apical diameter, regeneration procedures were successful with apical diameters as small as 0.5 mm. However, teeth with preoperative wider diameters (≥1 mm) demonstrated greater increase in root thickness, length, and apical narrowing.