Exploring a Paradigm Shift in Primary Teeth Root Canal Preparation: An Ex Vivo Micro-CT Study.

Traditional hand instrumentation is a commonly used technique to perform pulpectomy in deciduous teeth by most specialists in pedodontics. Lately, dentists have embraced rotary instrumentation as a safe and effective alternative. This study aimed to compare the efficacy of root canal preparation in extracted primary molars between manual and two rotary file systems using micro-CT. Thirty-six extracted human second primary mandibular molars were divided into three groups according to the instrumentation method: (1) Manually instrumented (MI) group (n = 9) in which the teeth were treated using K-files up to size 30; (2) Kedo-Ssystem (KS) group (n = 9); (3) ProTaper Gold system (PTG) group (n = 10) and control group (n-8). Each tooth was scanned before and after the retrograde root canal preparation. Residual dentin volume was calculated using micro-CT scans to evaluate the technique's efficacy. Additionally, the preparation time and procedural errors were recorded for each tooth preparation. A one-way ANOVA test was carried out to compare the groups' dentin volume and preparation time. The mean preparation time using the manual method (13.14 min) was more than two times longer than that of the rotary techniques (4.62 min and 6.45 min). The manual preparation method using a K-file removed almost half the root canal material when compared with the rotor method (p = 0.025). Conclusion: our results suggest that rotary instrumentation is more efficient for root canal preparation in primary teeth than the traditional manual method. This finding may call for a paradigm shift in current clinical practices, where manual instrumentation is still commonly preferred.

Bacterial Colonization and Proliferation in Primary Molars following the Use of the Hall Technique: A Confocal Laser Scanning Microscopy Study.

Restorative dentistry aims to create a favorable environment to arrest caries with minimal operative intervention. The Hall technique (HT) involves the seating and cementation of stainless steel crowns (SSC) on primary molars without any tooth preparation, caries removal, or local anesthesia. In this manner, it entombs bacteria and arrests caries' progress. We compared bacterial distribution and quantity among primary molars affected with caries and restored with SSC using the HT (n = 10), the conventional technique (CT; n = 10), or not restored at all (control; n = 10). The teeth were contaminated with Enterococcus faecalis to mimic the clinical situation in the oral cavity and then incubated for 21 days. They were then cut mesiodistally and evaluated with confocal laser scanning microscopy. Total bacterial load (live + dead) in the mesial and distal areas of the crown showed no significant difference between the groups (p = 0.711), but there were significantly more dead than live bacteria in the CT and control groups versus the HT group (p = 0.0274 and p = 0.0483, respectively). Inside the pulp chamber and the crown area, the total bacterial load was significantly higher in the HT compared to the CT group (p < 0.001). Significantly more dead than live bacteria were observed in all tooth areas treated with the HT (p = 0.0169). Bacterial penetration depth was significantly correlated with bacterial load (p = 0.0167). In conclusion, although more bacteria were present in teeth that had undergone the HT versus those treated with the CT, they were mainly unviable. Additionally, the CT and the HT showed a similar performance in terms of marginal leakage, indicating that complete caries removal is not essential to achieve good sealing.

The Effect of General Anesthesia on the Outcome of Root Canal Treatment in Pediatric Patients-A Retrospective Cohort Study.

This study aimed to evaluate the effect of general anesthesia (GA) on the 1-year outcome of Root Canal Treatment (RCT) performed in pediatric patients and to compare it to the outcome of RCT in pediatric patients without GA. Patients admitted for RCT in permanent dentition in a public hospital, dated 2015 to 2020, age 8-15 with a minimum of one year follow-up period, were included in the study. The sample consisted of 326 teeth from 269 patients treated by a single operator, with a recall rate of 81%. Overall, 124 teeth were treated under GA and 142 teeth were without GA. The mean follow-up time was 31.5 months. Data underwent statistical analysis and the significance threshold was set for p < 0.05. Of the total cases, 90% showed favorable outcomes. A significantly higher favorable outcome was seen in the GA group than in the non-GA group (98% and 85%, respectively, p < 0.001). The outcome was significantly affected by the type and quality of the coronal restoration, degree of root development, and lesion size (p < 0.05). According to the current study, in uncooperative pediatric patients, a more favorable outcome of root canal treatment can be obtained under GA than LA if the procedure is carried out with immediate restoration.

Quantifying Coronal Permanent Tooth Discoloration Caused by Different Pulpotomy Materials.

INTRODUCTION: Bioceramic materials, gray and white mineral trioxide aggregate (GMTA, WMTA), have been shown to have high rates of success in various endodontic applications. A major drawback is their tendency to discolor teeth compared to Biodentine (BD), that has been claimed not to discolor teeth. The aim of this study was to compare tooth discoloration after applying different pulpotomy base materials (BD, GMTA and WMTA). STUDY DESIGN: Forty human incisors teeth were used in this study. Coronal access was achieved by a Tungsten Carbide drill, and the pulp chambers were accessed and chemo-mechanically debrided. Each material was placed in the pulp chamber, up to the cervical sectioning level. All specimens were incubated at 37°C and 100% humidity for three months and have been evaluated before the study and weekly. Color was assessed according to the CIE L*a*b* color space system. RESULTS: ΔE of all experimental groups (GMTA, WMTA and BD) were significantly different from the control group at all time points (P<0.05). Color changes in the GMTA and WMTA groups, had no statistically significant differences, but showed higher discoloration compared to BD group in the cervical part of the crown, since week 1 (P<0.05). WMTA group showed significant discoloration in the cervical part as of week 1 (P<0.05), and gradually increased over time (Figure 2). BD group showed no significantly discoloration over time. GMTA group showed the significant discoloration at week 1 and week 14 (P<0.05). CONCLUSIONS: both GMTA and WMTA pulpotomy materials may discolor tooth structure over time in an extracted permanent anterior tooth model. When choosing bioceramic pulpotomy material, BD may be preferable in esthetic area.

Assessment of the Knowledge and Approach of General Dentists Who Treat Children and Pediatric Dentists Regarding the Proper Use of Antibiotics for Children.

Background: Antibiotics are widely used in dentistry. Dentists often provide antibiotics unnecessarily. Excessive use can induce resistant bacterial strains. There are certain indications for the proper use of antibiotics for pediatric dentistry according to the European and American Pediatric Dentistry (EAPD and AAPD). Very often dentists do not follow these guidelines. Objectives: This study aims to examine the level of knowledge among general dentists (who also treat children) and pediatric dentists on proper use of antibiotics. In addition, we examined whether there is unjustified use of antibiotics, if dentists are aware of the new and conservative approach of administering antibiotics to patients, and whether there is a relationship between years of professional seniority and dentist's knowledge level of proper use of antibiotics. Methods: One hundred general dentists (GD) who treat children in addition to 100 pediatric dentists (PD) completed the study questionnaires which measured knowledge, practice and attitudes regrading using antibiotics during dental treatment among children. Results: The general average of level of knowledge on proper use of antibiotics among general dentists was relatively low for both GD (60.7%) and PDs (65%). PDs demonstrated a relatively greater knowledge of correct use of antibiotics, especially in cases of endodontics and trauma. PDs also showed higher awareness to latest guidelines for the admission of "prophylactic antibiotics" according to the American Association (AAPD) and/or the European Union (EAPD) compared with GDs (86.2% vs. 66.3%). Conclusion: The level of knowledge of both general dentists and pediatric dentists is poor, with a large percentage of dentists from both groups not knowing whether antibiotics are needed in a specific dental case or not. Compliance with the EAPD/AAPD guidelines is also low and inadequate. The method of prescribing antibiotics given by dentists can be improved by increasing awareness, educational initiatives, and postgraduate courses among dentists regarding the recommended indications.

Influence of Irrigation Protocol on Peroxide Penetration into Dentinal Tubules Following Internal Bleaching: A Confocal Laser Scanning Microscopy Study.

INTRODUCTION: Discoloration of anterior teeth can result in cosmetic impairment in young children. The walking bleach technique stands out because of its esthetic results with minor side effects. Little information is available regarding the influence of various irrigation solutions on peroxide penetration. The aim of this study is to evaluate the influence of different irrigation protocols on peroxide penetration into dentinal tubules using confocal laser scanning microscopy (CLSM). STUDY DESIGN: Cavity preparations were made in 50 extracted permanent premolars. The teeth went through different irrigation sequences: A. control B. saline C. EDTA, NaOCl D. phosphoric acid E. EDTA, NaOCl, phosphoric acid. Then, mixture of fluorescent dyed sodium perborate paste was placed along the pulp chamber and the coronal access cavity, and was refilled at days 7, 14 and 21. RESULTS: The minimal and maximal penetration depths were 324 and 3045 µm, respectively, with a mean of 1607µm. The stained areas were significantly larger in the buccal and lingual directions (P<0.05). Groups B and C showed significantly larger penetration in weeks 2 and 3 compared to week 1 (P<0.05). Group D and E showed significantly larger penetration compared to groups B and C at all times (P<0.05). CONCLUSION: Bleaching agents penetrate to the extra-radicular region of teeth; however, the level of peroxide penetration is significantly higher when the irrigation sequence consists of phosphoric acid prior the bleaching agent placement.

Effect of cone beam computed tomography voxel size and dental specialty status on the agreement of observers in the detection and measurement of periapical lesions.

OBJECTIVE: To compare observer agreement between endodontists and oral and maxillofacial radiologists (OMRs) in the detection and measurement of periapical lesions as depicted in cone beam computed tomography (CBCT) with 2 voxel sizes. STUDY DESIGN: In total, 256 CBCT images of maxillary molars were evaluated by 2 endodontists and 2 OMRs. Images were obtained at voxel sizes of 0.2 and 0.4 mm. Observers evaluated 64 endodontically and 64 nonendodontically treated teeth for the presence of periapical lesions using a 5-point confidence scale. Weighted κ values were calculated to determine intra- and interobserver agreement. Intraclass correlation coefficients (ICCs) were calculated to assess intra- and interobserver agreement in width and height measurements of the lesions. RESULTS: Intraobserver agreement ranged from fair to almost perfect, with κ values higher for the OMRs than for the endodontists. Interobserver agreement between endodontists ranged from fair to moderate at the 0.2mm voxel size and was slight at 0.4 mm. Agreement between OMRs was almost perfect at 0.2 mm and ranged from substantial to almost perfect at 0.4 mm. ICC was excellent for all observers in all conditions. CONCLUSIONS: Intra- and interobserver reliability was affected by voxel size and specialty. Correlation for measurements exhibited no variation.

Effects of different irrigation protocols on dentin surfaces as revealed through quantitative 3D surface texture analysis.

The combination of ethylenediaminetetraacetic acid (EDTA) and sodium hypochlorite (NaOCl) has been advocated as an effective irrigation methodology to remove organic and inorganic matter in root canal therapy. Yet, it was suggested that both solutions might lead to structural changes of the dentinal wall surface, depending on the order of application which might affect sealer mechanical retention. This study aims to evaluate the effect of different irrigating protocols on dentin surface roughness using quantitative 3D surface texture analysis. Data stems from 150 human root dentin sections, divided into five groups, each prepared according to one of the following protocols: Negative control; 17% EDTA; 17% EDTA followed by 5.25% NaOCl; 5.25% NaOCl; and 5.25% NaOCl followed by 17% EDTA. Each dentin sample was examined for its three-dimensional surface texture using a high-resolution confocal disc-scanning measuring system. EDTA 17% and the combined EDTA 17% with NaOCl 5.25% showed considerably higher roughness properties compared to the control and to NaOCl 5.25% alone. However, the irrigation sequence did not affect the dentin roughness properties. Therefore, mechanical retention is probably not dependent upon the selection of irrigation protocol sequence.

Prevalence of dens invaginatus in young Israeli population and its association with clinical morphological features of maxillary incisors.

Dens invaginatus is an anomaly mostly observed in maxillary incisors. This study aimed to assess the prevalence of dens invaginatus in maxillary incisors in young Israeli population and to study its potential association with clinical coronal morphological features. Data was collected from periapical radiographs and clinical photographs of patients from Orthodontics Department between 2006 and 2018. Radiographic characteristics were evaluated and compared to clinical coronal morphological features. Statistical analysis was performed using the Pearson chi-square test with statistical significance set at p < 0.05. The sample included 1621 maxillary incisors from 547 patients. Dens invaginatus was observed in 422 (26%) of these teeth. Maxillary lateral incisors were more affected than central incisors. In 103 patients dens invaginatus was unilateral, while in all other cases it was bilateral. Unique clinical morphological characteristics were observed in 88% of the teeth that exhibited radiographic evidence of dens invaginatus. Dens invaginatus Type I was most frequently observed, accounting for 90% of the teeth. A significant association between clinical coronal morphological features and dens invaginatus was detected. Dens invaginatus is common in maxillary incisors of the study population. Several clinical morphological features may predict the presence of dens invaginatus.

The Effect of Pulpotomy Base Material on Bacterial Penetration and Proliferation for Pulpotomized Primary Molar Teeth: A Confocal Laser Scanning Microscopy Study.

Introduction: the study aimed to evaluate Enterococcus Faecalis colonization in the pulp chamber in pulpotomized extracted human teeth filled by different pulpotomy base materials (PBMs), using confocal laser scanning microscopy (CLSM). Study design: Cavity preparations were made in 70 extracted primary molars. The pulp chambers were filled using either Intermediate restorative material (IRM), Mineral Trioxide Aggregate (MTA) or Glass ionomer (GI). Twenty-five teeth served controls. The specimens were sterilized, and coronally filled with bacterial suspension for 21 days. The specimens were cut through the furcation area, stained using LIVE/DEAD BacLight Bacterial Viability Kit and evaluated using CLSM. Results: The extent of fluorescent staining was larger in the GI group, compared to the IRM and MTA groups, and larger in the IRM group compared to the MTA group (P<0.05). The minimal and maximal bacterial penetration depths into the dentinal tubules were 55 and 695μm, respectively (mean 310μm), without differences between the materials (GI, IRM, MTA, p>0.05). The ratio of live bacteria to dead bacteria within the evaluated areas was higher in the GI group compared to the IRM and the MTA groups, and higher in the IRM group compared to the MTA group (P<0.05). There were no differences between the mesial, distal and apical parts in any of the evaluations (p>0.05). Conclusions: bacteria colonize the interface between the PBM and dentin and penetrate deeply into the dentinal tubules. The extent and the vitality of the colonized bacteria may be affected by the type of PBM.

Indications for root canal treatment in asymptomatic teeth with various radiographic findings: guidelines for general dental practice.

OBJECTIVES: The purpose of this article was to propose guidelines for dental practitioners facing the dilemma whether to treat, follow up, or disregard random asymptomatic radiographic findings. DATA SOURCES: Searches performed in MEDLINE, Cochrane, and EMBASE databases were followed by a manual search. Related data incorporated by experts included recommendations on asymptomatic root canal treatment, quality of the root canal, and restoration relative to outcome. Evidence tables were developed following quality and inclusion criteria assessment. RESULTS: The initial search retrieved 2,796 MEDLINE, 542 EMBASE, and 152 Cochrane articles, for a total of 3,490 potential articles. After duplicates were removed, 2,946 articles remained. Articles not related to the topic and not meeting eligibility criteria were excluded, resulting in 44 studies included in this scoping review. CONCLUSIONS: The proposed guidelines provide easy access to existing information in endodontics. The findings are common and possess clinical and medico-legal importance.

Bacterial colonization in the apical part of extracted human teeth following root-end resection and filling: a confocal laser scanning microscopy study.

OBJECTIVES: The purpose of this study was to evaluate Enterococcus faecalis colonization at the apical part of root canals following root-end resection and filling using confocal laser scanning microscopy (CLSM). MATERIALS AND METHODS: The apical 3-mm root-ends of 55 extracted single rooted human teeth were resected, and 3-mm retrograde cavities were prepared and filled using either mineral trioxide aggregate (MTA), intermediate restorative material (IRM), or Biodentine (n = 10 each); 25 teeth served as controls. The roots were placed in an experimental model, sterilized, and coronally filled with E. faecalis bacterial suspension for 21 days. Then, the apical 3-mm segments were cut to get two slabs (coronal and apical). The slabs were stained using LIVE/DEAD BacLight Bacterial Viability Kit and evaluated using CLSM. RESULTS: The fluorescence-stained areas were larger in the bucco-lingual directions compared with the mesio-distal directions (p < 0.05). The mean and maximal depths of bacterial colonization into the dentinal tubules were 755 and 1643 µm, respectively, with no differences between the root-end filling materials (p > 0.05). However, more live bacteria were found in the MTA group in comparison to IRM and Biodentine groups (p < 0.05). CONCLUSIONS: CLSM can be used to histologically demonstrate bacterial root-end colonization following root-end filling. This colonization at the filling-dentine interfaces and deeper into the dentinal tubules may be inhomogeneous, favoring the bucco-lingual aspects of the root. CLINICAL RELEVANCE: Following root-end resection and filling bacterial colonization may lead to inflammatory reactions at the periapical tissues; the viability of the colonized bacteria may be affected by the type of root-end filling material.

Eradication of Enterococcus faecalis Biofilms on Human Dentin.

Objectives: This work assesses different methods to interfere with Enterococcus faecalis biofilms formed on human dentin slabs. Methods: First, methods are presented that select for small molecule inhibitors of biofilm targets using multi-well polystyrene biofilm plates. Next, we establish methodologies to study and interfere with biofilm formation on a medically relevant model, whereby biofilms are grown on human root dentin slabs. Results: Non-conventional D-amino acid (D-Leucine) can efficiently disperse biofilms formed on dentin slabs without disturbing planktonic growth. Cation chelators interfere with biofilm formation on dentin slabs and polystyrene surfaces, and modestly impact planktonic growth. Strikingly, sodium hypochlorite, the treatment conventionally used to decontaminate infected root canal systems, was extremely toxic to planktonic bacteria, but did not eradicate biofilm cells. Instead, it induced a viable but non-culturable state in biofilm cells when grown on dentin slabs. Conclusion: Sodium hypochlorite may contribute to bacterial persistence. A combination of the methods described here can greatly contribute to the development of biofilm inhibitors and therapies to treat Enterococcus faecalis infections formed in the root canal system.