Micro-CT evaluation of four final irrigation protocols on hard-tissue debris removal from mesial roots of mandibular molars containing isthmus.

OBJECTIVES: To evaluate by means of microcomputed tomography (micro-CT), the efficacy of four final irrigation protocols in the removal of hard-tissue debris (HTD) in mesial roots of mandibular molars containing isthmus. MATERIALS AND METHODS: Forty standardized mesial roots of extracted mandibular molars presenting isthmus were selected. The root canals were prepared and randomly divided into 4 groups (n = 10): EA, EndoActivator (Dentsply Sirona); EC, Easy Clean (Easy Dental Equipment, Belo Horizonte, Brazil); XPF, XP-Endo Finisher (FKG Dentaire, La Chaus-de Fonds, Switzerland); and PUI, passive ultrasonic irrigation using Irrisafe tip (Satelec Acteon, Merignac, France). Each final irrigation protocol was performed in two cycles (60 s), using, respectively, 2.5% sodium hypochlorite and 17% EDTA. Micro-CT scans were obtained pre-operatory, post-preparation, and post-irrigation. The percentage of HTD reduction was calculated. Data was analyzed statistically (ANOVA and Kruskal-Wallis, significance set at 5%). RESULTS: The percentage of HTD reduction was greatest for the XPF group (77.92%), followed by EA (62.92%), PUI (47.48%), and EC (32.65%). Statistical differences (p < .05) were found between XPF and EC only. A significant difference (p < .05) was found between XPF and EC in all thirds and between PUI and EC in the middle third. CONCLUSIONS: XPF, EA, and PUI were similarly effective in HTD reduction. However, none of the evaluated protocols was able to completely remove all the debris. CLINICAL RELEVANCE: Final irrigation protocols aim to clean the canal complexities that are not addressed by the shaping procedures. Micro-CT allowed to assess the removal of hard-tissue debris in the isthmus and canals of mandibular molars.

Influence of Filling Material Remnants on the Diffusion of Hydroxyl Ions in Endodontically Retreated Teeth: An Ex Vivo Study.

AIM: To assess the influence of remnants of filling material on hydroxyl ion diffusion from calcium hydroxide (CH) paste, measured by the pH value, in retreated teeth. MATERIALS AND METHODS: A total of 120 single-rooted extracted teeth were prepared up to a size 35 hand file and filled. For retreatment, the specimens were divided into four groups (n = 20): ProTaper Universal Retreatment (PUR), PUR with additional instrumentation (PURA), Mtwo Retreatment (MTWR), and MTWR with additional instrumentation (MTWRA). Negative (NEG) and positive (POS) control groups were composed by 20 specimens each one. The specimens, except NEG, were filled with CH paste. The retreated groups were scanned using cone-beam computed tomography (CBCT) for analysis of filling remnants. The pH assessment was performed at the baseline, after seven, 21, 45, and 60 days of immersion in saline. Data were analyzed using Shapiro-Wilk and Levene's test, followed by a two-way analysis of variance (ANOVA) and Tukey's test. RESULTS: Additional instrumentation (PURA and MTWRA) were superior regarding removal of the filling material (p <0.05); however, without significant difference (p >0.05). The mean pH value in all groups increased (p <0.05). After 60 days, no statistical difference was observed among POS and PURA; and MTWR and MTWRA. There was less diffusion of hydroxyl ions when the amount of remnants was greater than 59%. CONCLUSION: Additional instrumentation improved the ability to remove filling material in both systems. All groups presented increasing pH; however, the higher the amount of remnants, the lower the diffusion of hydroxyl ions. CLINICAL SIGNIFICANCE: The amount of remnants allows less diffusion of calcium hydroxyl ions. Thus, additional instrumentation improves the ability to remove these materials.

Accuracy of electronic apical functions of a new integrated motor compared to the visual control of the working length-an ex vivo study.

OBJECTIVES: To evaluate ex vivo the efficacy of the integrated motor Tri Auto ZX2 in controlling the apical extent of preparation compared to conventional visual control (CVC) of the working length (WL). MATERIALS AND METHODS: Eighty standardized mandibular premolars were divided into five groups (n = 16). In the CVC group, instruments were used in continuous rotation (CR) and visual control performed by means of rubber stoppers. For each of the remaining groups, it was assigned a combination of a motion (CR or optimal torque reverse (OTR)), and an apical function (Auto Apical Reverse (AAR) or Optimum Apical Stop (OAS)). Root canals were prepared using the apical functions at 0.5 mark using an alginate model. Difference between the final WL and the actual length post-instrumentation was calculated. Data were analyzed statistically with the significance set at 5% (ANOVA, Tukey HSD). RESULTS: There was no difference in the mean WL among the groups, except between the CR combined to OAS compared to CVC (P > 0.05). Although CVC resulted in two cases beyond the foramen, no significant difference was found among the groups when comparing the distributions of measurements (P > 0.05). CONCLUSIONS: All combinations of motion and apical control functions of Tri Auto ZX2 provided an adequate apical limit ex vivo, similar to the visual control using rubber stoppers. CLINICAL RELEVANCE: TriAuto ZX2 was efficient to control the apical extent of preparation dispensing the need for calibrating the files, regardless of the different settings. This motor might potentially prevent over-instrumentation by continuously monitoring the apical limit.

Dissimilar Sequelae Caused by Single Dental Trauma: A Case Report with Long-Term Follow-up.

Immediate care and accurate diagnosis are essential for treating dental trauma. This report presents a 7-year-old boy suffered a bicycle accident with direct trauma to the mouth and extrusive luxation of teeth #11 and #21. The emergency treatment was performed within the first hour. Clinical examinations showed that both teeth exhibited 3 mm extrusion from comparing their incisal edges to their neighboring teeth, had edematous gingiva, showed grade 3 mobility and were painful to percussion. Radiographic exams showed incomplete root formation, widened periodontal spaces along their entire lengths and absence of bone or root fractures. The treatment consisted of immediate repositioning and semi-rigid splinting. After 15 days, tooth #11 exhibited no clinical signor symptom and tooth #21 was diagnosed with pulp necrosis, with an acute dentoalveolar abscess and intraoral edema. Immediate endodontic treatment was initiated (intracanal dressing with calcium hydroxide paste). At 30 days, another pulp sensibility test was performed on tooth #11, which had a negative response. In the same visit, the intracanal dressing of tooth #21 was replaced. The Ca(OH)2 medication was replaced every 6 months until the formation of an apical barrier. The final dressing consisted of gutta-percha and Grossman's sealer and was placed two and a half years after the first dressing appointment. The extrusive luxation resulted in two different sequelae: complete root obliteration in tooth #11 and anomalous root development after the formation of an apical barrier in tooth #21. The patient received orthodontic treatment after 6 years from the initial treatment with no negative outcome. After 18 years follow-up, both teeth were stabilized with no symptom or sign. It's important to follow the evolution of every trauma case continuously because the sequelae can be unpredictable.

Virtual Versus Conventional Planning in Orthognathic Surgery: A Systematic Review and Meta-analysis.

Objectives: The purpose of this study was to compare the accuracy of hard tissues movements planned to result of the maxillary and mandibular positions between conventional surgical planning (CSP) and virtual surgical planning (VSP) in patients undergoing orthognathic surgery. Methods: A systematic electronic search was carried out in six databases and gray literature with no restriction of publication date and language. Clinical observational studies that compared accuracy of maxillary position between CSP and VSP were included. Linear measurements of the mandible in the transverse plane and linear measurements of the maxilla in the vertical, horizontal and transverse planes were considered for analysis, comparing planned to postoperative outcomes of CSP and VSP. Cochrane tool was used to assess bias risk. A meta-analysis was performed to summarize similar results by using the Review Manager 5.3 software. Significance level was set at 5%. Results: Six studies (2 RCT and 4 retrospective cohorts) were included according to inclusion and eligibility criteria, involving 255 patients. The inter-rater reliability of selection and eligibility was excellent (k = 0.8315 and k = 0.9329, respectively). Two studies presented that VSP seemed to have better results than CSP regarding linear measurements of the mandible in the transverse plane. Results from CSP and VSP were similar in accuracy for hard tissue in vertical plane of maxillary position (I2 = 0%; p = 0.17), although VSP was more accurate in horizontal plane (I2 = 0%; p = 0.02). Conclusion: VSP presented better accuracy for transverse movements in mandible of asymmetric patients. VSP showed to be more accurate for movements in the horizontal plane, and qualitative analysis seemed to be more effective for transverse movements.

Retrospective analysis of survival of avulsed and replanted permanent teeth according to 2012 or 2020 IADT Guidelines.

This study aimed to compare the survival of replanted teeth that followed the 2012 or the 2020 International Association of Dental Traumatology (IADT) guidelines. Sixty-two permanent replanted teeth were retrospectively assessed (IADT 2012, n = 45; IADT 2020, n = 17). Five years after replantation (from January 2017 to December 2021), clinical and radiographic examinations were performed. A significance level of 95% was considered to evaluate the outcomes. Thirty-one teeth (50.0%) remained in their sockets and 31 (50.0%) were lost due to external root resorption. Of the 25 (40.3%) teeth replanted within one hour, 16 (64.0%) remained in their sockets, and 9 (36.0%) were lost. Twenty-two (71.0%) of all 31 lost teeth had an extra-alveolar time of more than one hour. Twelve teeth remained in their sockets without resorption: 8 (66.7%) were replanted within one hour, 2 (16.7%) followed the 2012 IADT, and 2 (16.7%) the 2020 IADT guidelines for late replantation. There was a significant difference (p <0.05) in the extra-alveolar time (< one hour), but without difference between the guidelines in late replantation (p > 0.05). Replanted teeth following both, 2012 or 2020 IADT guidelines, have similar clinical outcomes. The extra-alveolar time of less than one hour was demonstrated to be important to keep the permanent tooth in its socket.

Effect of Different Root Canal Drying Protocols on the Bond Strength of Two Bioceramic Sealers.

OBJECTIVES: This study evaluated in vitro the effect of two different drying protocols on the dentin bond strength of two different bioceramic sealers (Sealer Plus BC [SP] and Bio C Sealer [BCS]). Bond strength and failure mode were evaluated according to the sealer, drying protocol, and root canal third. MATERIALS AND METHODS: Sixty extracted human mandibular single-rooted premolars were selected after anatomical standardization. The crowns were sectioned and root canals were prepared. Roots were randomly divided into four groups (n = 15 each). Each group was assigned a combination of one of the evaluated sealers (SP or BCS) and one of the drying protocols: canals dried with paper points (PP) or irrigation with saline followed by aspiration with silicon cannulas (IA). Obturations were performed using a single-cone technique. The teeth were temporized and stored for 7 days (100% humidity, 37°C). Roots were cut to obtain 2 mm thick discs for each third (coronal, middle, and apical). Push-out tests were performed on a universal testing machine, and the bond strength (MPa) of each specimen was calculated by dividing the load (N) by the interface area. Failure type was assessed under ×4 magnification. STATISTICAL ANALYSIS: Data were statistically analyzed with a significance set at 5%. An analysis of variance test followed by the Games-Howell post-hoc test was used to compare the mean values between the groups and the interaction of the variables. RESULTS: The predominant failure type was cohesive, followed by mixed failure and adhesive in all groups. The apical third presented the highest bond strength (p < 0.05) regardless of the group, followed by the middle and coronal thirds. Overall, the SP PP group had the highest mean bond strength (p < 0.01), but the SP sealer was negatively affected by the IA drying protocol in the coronal and middle thirds. The BCS presented similar results within the third stage, regardless of the drying protocol. CONCLUSIONS: Sealer Plus BC had a higher bond strength than Bio C Sealer, but it was negatively affected by the irrigation-aspiration protocol in the coronal and middle thirds. For the apical third, there was no difference between the groups; thus, a similar bond strength was observed regardless of the drying protocol or sealer.

Influence of clinical factors, IL4 and IL6 genes polymorphisms in functional healing in late replantation.

To investigate the genetic association in a sample of replanted teeth, it is necessary to observe the extreme phenotypes, such as, teeth that underwent functional healing and those extracted due to severe external root resorption. Thus, this study aimed to investigate the association of age of the patients, root development, storage media, and polymorphisms in the interleukin 4 (IL4) and interleukin 6 (IL6) genes with teeth that presented extreme outcomes, as functional healing or extraction, in a group whose replantation techniques did not follow the International Association of Dental Traumatology (IADT) 2012 guidelines. Forty-three avulsed and replanted teeth that did not follow IADT 2012 guidelines and underwent functional healing or were extracted were included. Periapical radiographs employed for this study were taken soon after tooth replantation and after 1 year. For genotypic IL4 and IL6 genes analysis, DNA of oral mucosa cells was extracted. Real-time- PCR performed for genotyping polymorphisms in IL4 and IL6 genes. Clinical and genetic variables were analyzed by the Chi-square test and the "Z" test. P values < .05 were considered significant. The results showed that functional healing and extraction were associated with storage media and with the rs2243268 of IL- 4 gene polymorphisms. As conclusion, the C rs2243268 allele of IL4 gene may have a positive relationship with functional healing teeth that were replanted not following the 2012 IADT guidelines. Keeping the tooth dry is associated to a fast loss of avulsed and replanted teeth after 1-year follow-up.

The role of polymorphism of the IL6 gene in tooth replantation.

The absence or presence of root resorption on the root surface of a replanted tooth indicates an immune-inflammatory reaction. Since interleukin-6 (IL-6) is considered an inflammatory marker in bone resorption, this study aimed to investigate the association between clinical variables and polymorphisms in IL6, with the outcome of replanted teeth at 1-year follow-up. Altogether, 127 avulsed teeth that were replanted and had their root canals treated were selected for this study. Periapical radiographs were taken after replantation and after 1 year. Real-time PCR was used to genotype IL6 polymorphisms. Chi-square and 'Z' tests were performed to verify the association between genetic variables and the prognosis of replanted teeth (P < 0.05). An association was observed between the rs2069843 polymorphism of IL6 and the outcome of replanted teeth (P < 0.05). The rs2069843 polymorphism of IL6 may influence the outcome of avulsed and replanted teeth in the first year post-trauma.

Spontaneous eruption of a canine after marsupialization of an infected dentigerous cyst.

A dentigerous cyst is the most common developmental odontogenic cyst. It is a benign and asymptomatic intraosseous lesion that affects the bones of the maxillofacial complex, interfering with tooth eruption. This article reports the spontaneous eruption of a canine after marsupialization of an infected dentigerous cyst and extraction of the deciduous teeth. A radiograph showed a large cyst with a radiolucent area involving the mandibular left deciduous canine and first molar, and the permanent canine and first premolar. Although enucleation is the treatment of choice, marsupialization is the best option for large cysts involving an unerupted permanent tooth, as in this case. The patient was followed for 1 year, and eruption of the permanent canine and first premolar and gradual reduction of the radiolucent area were observed.

Management of Dental Intrusion and Lateral Luxation: Case Report with 10 Years Follow-up.

This case report documents the clinical approach adopted for two maxillary incisors with intrusion and lateral luxation trauma. The proposed procedures involved reposition of both teeth, one of them with surgical extrusion and endodontic procedure for both, with 10 years of follow-up.

Influence of Different Irrigation Solutions and Instrumentation Techniques on the Amount of Apically Extruded Debris.

OBJECTIVE: The objective of the present study was to evaluate the influence of different irrigation solutions on the amount of extruded residues apically, varying the instrumentation technique in manual, continuous rotation, or reciprocation motions. The amounts of residue for each irrigation solution was also assessed. METHODS: Two tests were performed. In the first test, 90 mandibular premolars were divided into nine groups (n=10). Each group was subjected to a different technique: ProTaper Universal, WaveOne Gold, or manual instruments, with different irrigation solutions [2.5% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX) gel, or distilled water]. During the preparation of the root canal, the apically extruded material was collected in previously weighed glass vials. In the second test, irrigation solutions were weighed separately with the same weighing method. Data were analyzed using the Kolmogorov-Smirnov, one-way and two-way ANOVA, Levene, Tukey, and Games-Howell tests. RESULTS: Apically extruded debris was observed in all groups. ProTaper Universal with continuous rotation using 2% CHX gel resulted in the greatest amount of debris (P<0.001). There were significant differences in the amounts of residue among the different groups (P<0.001). Moreover, when the weighing of the irrigation solutions was tested, the 2.5% NaOCl solution produced the greatest amount of residues compared with other irrigation solutions. CONCLUSION: Different irrigation solutions influenced the amount of apically extruded debris during the preparation of the canal among the different instrumentation techniques. The ProTaper technique using 2% CHX gel resulted in the greatest amount of apically extruded debris.

Assessment of platelet-rich fibrin in the maintenance and recovery of cell viability of the periodontal ligament.

This study analyzed the efficacy of autologous platelet-rich fibrin (PRF) in maintaining and recovering cell viability of the periodontal ligament (PDL). The PDL cells were isolated from 45 extracted teeth randomly distributed among 6 groups: 5 min, 1 h, 2 h, PRF 30 min, PRF 1 h and PRF 2 h. In the groups 5 min, 1 h and 2 h (n = 5), the teeth were kept dry in extra-alveolar times of 5 min, 1 h and 2 h respectively. The teeth of the groups PRF 30 min, PRF 1 h and PRF 2 h (n = 10) were kept dry at extra-alveolar times of 30 min, 1 and 2 h followed by immersion in PRF for 45 min. PDL cells were isolated by enzymatic digestion with type II collagenase and dispase, counted and analyzed for viability with Trypan blue vital dye in Neubauer chamber. The variables total number of cells and cell viability demonstrated that in the 5 min, 1 h and 2 h groups there was a decrease after the extra-alveolar dry times of 1 and 2 h. In comparison with the total number of cells, group 1 h, considered immediate reimplantation, did not present statistical difference when compared to the groups PRF 30 min, PRF 1 h and 2 h, a result that demonstrates that PRF assists in cell maintenance and recovery. PRF provided increased cell viability in relation to the different dry extra-alveolar times analyzed (p < 0.001). Autologous PRF presented effectiveness in maintaining and recovering PDL cells from extracted teeth and kept dry for up to 2 h.

Accuracy of Digital Periapical Radiography and Cone-beam Computed Tomography for Diagnosis of Natural and Simulated External Root Resorption.

INTRODUCTION: The aim of this study was to compare the sensitivity and specificity of digital periapical radiography and cone-beam computed tomographic (CBCT) imaging in the detection of natural and simulated external root resorptions (ERRs) with micro-computed tomographic (micro-CT) imaging as the reference standard. METHODS: One hundred twenty-six teeth were scanned using the SkyScan 1172 micro-CT scanner (Bruker microCT, Kontich, Belgium), and the images were evaluated using NRecon software (Bruker microCT). After micro-CT imaging, the teeth were divided into 3 groups: control, 42 teeth that did not present any ERR cavities; natural, 42 teeth that presented 1 or more ERR cavities; and artificial, 42 teeth without ERRs but perforations were created to simulate the cavities. Ortho-, mesio-, and distoradial digital periapical radiographs and CBCT images were obtained, and the images were evaluated by 2 double-blinded qualified radiologists. RESULTS: The sensitivities and specificities for the radiographic and tomographic methods were 78.18% and 97.27% and 59.52% and 97.62%, respectively. Within the individual groups, both methods had lower sensitivity and specificity for natural and artificial resorptions, and the differences were statistically significant. CONCLUSIONS: CBCT imaging was the best method for the detection of ERRs. Only 74.5% of natural ERR gaps were observed on the digital periapical radiographs and 94.5% on CBCT imaging; in the artificial group, this number increased to 81.8% and 100%, respectively. The configuration of the natural ERR gaps is different from those artificially simulated and is much more difficult to observe.

The Accuracy of a New Cone-beam Computed Tomographic Software in the Preoperative Working Length Determination Ex Vivo.

INTRODUCTION: This study investigates the accuracy of 3D Endo software (Dentsply Sirona, Salzburg, Austria) to determine the working length when using preoperative cone-beam computed tomographic (CBCT) scans of extracted teeth, compared with conventional CBCT software and an electronic apex locator (EAL). METHODS: CBCT scans of 30 premolars were obtained. Using OnDemand3D software (Cybermed, Seoul, Korea), the measurement obtained from the coronal reference to the apical foramen (AF) was recorded as the conventional CBCT length. Then, using 3D Endo software (Dentsply Sirona), the suggested length (3D-SL) and the operator-adjusted length (3D-OL) were obtained. Teeth were accessed, and the actual length was measured. Finally, the teeth were embedded in alginate to obtain the electronic length (EL) using the EAL Root ZX (J Morita, Tokyo, Japan). The means of the absolute values and the percentages of distribution of the tested measurement methods were compared to the actual length. RESULTS: No difference was found regarding the mean measurements (analysis of variance, P > .05). All the CBCT measurements presented a high reliability (Dahlberg's formula). The measurements within a ±0.5-mm range from the AF were 86.6% for the 3D-SL, 80% for the 3D-OL and EL, and 73.3% for the CBCT length. The EL presented significantly fewer underestimated measurements (P < .05). The 3D-OL and 3D-SL presented significantly fewer measurements beyond the AF (P < .05). CONCLUSIONS: The preoperative working length determination using 3D Endo was reliable and similar to conventional CBCT software. However, the combined use of CBCT with an EAL is required to increase the accuracy in the location of the AF.

Retrospective analysis of survival of avulsed and replanted permanent teeth according to 2012 or 2020 IADT Guidelines

Abstract This study aimed to compare the survival of replanted teeth that followed the 2012 or the 2020 International Association of Dental Traumatology (IADT) guidelines. Sixty-two permanent replanted teeth were retrospectively assessed (IADT 2012, n = 45; IADT 2020, n = 17). Five years after replantation (from January 2017 to December 2021), clinical and radiographic examinations were performed. A significance level of 95% was considered to evaluate the outcomes. Thirty-one teeth (50.0%) remained in their sockets and 31 (50.0%) were lost due to external root resorption. Of the 25 (40.3%) teeth replanted within one hour, 16 (64.0%) remained in their sockets, and 9 (36.0%) were lost. Twenty-two (71.0%) of all 31 lost teeth had an extra-alveolar time of more than one hour. Twelve teeth remained in their sockets without resorption: 8 (66.7%) were replanted within one hour, 2 (16.7%) followed the 2012 IADT, and 2 (16.7%) the 2020 IADT guidelines for late replantation. There was a significant difference (p <0.05) in the extra-alveolar time (< one hour), but without difference between the guidelines in late replantation (p > 0.05). Replanted teeth following both, 2012 or 2020 IADT guidelines, have similar clinical outcomes. The extra-alveolar time of less than one hour was demonstrated to be important to keep the permanent tooth in its socket.

Resumo Este estudo teve como objetivo comparar a sobrevida, por cinco anos, de dentes reimplantados que seguiram as diretrizes de 2012 ou 2020 da International Association of Dental Traumatology (IADT). Sessenta e dois dentes permanentes reimplantados foram avaliados retrospectivamente (IADT 2012, n = 45; IADT 2020, n = 17). Cinco anos após o reimplante, foram realizados exames clínicos e radiográficos. Foi considerado um nível de significância de 95% para avaliar os desfechos. Trinta e um dentes (50,0%) permaneceram em seus alvéolos e 31 (50,0%) foram perdidos por reabsorção radicular externa. Dos 25 (40,3%) dentes reimplantados em uma hora, 16 (64,0%) permaneceram em seus alvéolos e 9 (36,0%) foram perdidos. Vinte e dois (71,0%) de todos os 31 dentes perdidos tiveram um tempo extra-alveolar superior a uma hora. Doze dentes permaneceram em seus alvéolos sem reabsorção: 8 (66,7%) foram reimplantados em uma hora, 2 (16,7%) seguiram a IADT de 2012 e 2 (16,7%) as diretrizes da IADT de 2020 para reimplante tardio. Houve diferença significativa (p<0,05) no tempo extra-alveolar (< uma hora), mas sem diferença entre as diretrizes no reimplante tardio (p > 0,05). Dentes reimplantados seguindo as diretrizes de 2012 ou 2020 da IADT, tiveram taxas de sucesso semelhantes. O tempo extra-alveolar inferior a uma hora demonstrou ser importante para manter o dente permanente em seu alvéolo.

Influence of Atopy in the Outcome of Avulsed and Replanted Teeth during 5 Years of Follow-up.

INTRODUCTION: The goal of replantation after dental avulsion is to maintain the tooth in its socket. Presence of vital periodontal ligament cells on the root surface of the replanted tooth and the immunologic status of the patient are factors that protect against root resorption. It is known that dental constituents play an active role in root resorption by inducing specific and non-specific immune responses; however, little information exists regarding the influence of the acquired immune response on replantation. Therefore, the aim of this study was to evaluate the 5-year outcome of replantation in non-atopic and atopic patients. METHODS: Clinical and radiographic examinations were performed in 62 replanted teeth during a 5-year period. The evaluation of atopy was based on the patients' personal and family histories and skin prick test results. The χ2 and the Z tests were used to assess the association between atopy and the outcome of the replanted teeth (P < .05). RESULTS: There were significant differences between the 1-year and 5-year outcomes of the replanted teeth (P < .05) and atopic and non-atopic patients who had their teeth extracted because of inflammatory or replacement root resorption after 5 years (P < .05). CONCLUSIONS: Being atopic may offer the advantage of loss of fewer teeth because of replacement resorption, whereas being non-atopic may create an advantage of loss of fewer teeth because of inflammatory root resorption during the first 5 years after trauma.

Comparison of the Efficiency of Rose Bengal and Methylene Blue as Photosensitizers in Photodynamic Therapy Techniques for Enterococcus faecalis Inactivation.

OBJECTIVE AND BACKGROUND: The aim of this in vitro study was to compare the efficiency of a photodynamic therapy (PDT) technique employing rose bengal (RB) and methylene blue (MB) as photosensitizers (PSs) to reduce the viability of Enterococcus faecalis, a well-known pathogen found in root canal systems. Currently, in several clinical applications, including in the field of endodontics, MB is employed in association with a red laser source for the photoinactivation of pathogenic bacteria. METHODS: In this study, MB was used at 0.01% (31.2 mol/L) in association with a red (660 nm) laser as the excitation source in the MB group (MBG). Alternatively, the same test was performed with RB (25 mol/L) that was associated with a green (532 nm) light laser source in the RB group (RBG). A saline solution (0.9%) was used in the control group. The colony-forming units per milliliter (CFU/mL) were calculated after 24 h of incubation at 37°C, and the statistical analysis was performed using ANOVA. RESULTS: The results showed a significant reduction in the CFU/mL in the RBG group (0.12 × 108) compared with the control (2.82 × 108) and MBG groups (2.66 × 108). For the concentration and laser intensity employed in the experiments, the MBG group repeatedly showed no significant reduction in bacterial counts compared with the control. Therefore, the best result regarding the reduction of E. faecalis viable cells was obtained with RB as the PS. CONCLUSIONS: PDT may be improved if RB is used in association with a green light laser source for the inactivation of E. faecalis.

Maintenance of Pulp after Horizontal Root Fractures in Three Maxillary Incisors: A Thirteen-Year Evaluation.

This case report documents the clinical approach adopted for three upper incisors with horizontal root fracture in the middle or cervical third. The proposed procedures involved maintaining pulp vitality and periodontal stability of the fractured teeth with 13 years of follow-up.

Efficacy of protaper instruments during endodontic retreatment.

INTRODUCTION: The effectiveness of ProTaper Universal and ProTaper Retreatment rotary instruments was compared to the Hedström files in the removal of filling material from root canals. MATERIALS AND METHODS: Thirty-six extracted human mandibular premolars with a single straight root canal were shaped and filled with gutta-percha and AH Plus. The specimens were stored for 6 months at 37°C and at 100% relative humidity, and then randomly divided into three groups: PTU - removal of filling material performed with ProTaper Universal instruments; PTR - removal of filling material performed with ProTaper Retreatment instruments; HF - removal of filling material performed with Gates-Glidden burs, Hedström files and solvent. After the filling material removal and diaphanization, the specimens were longitudinally sectioned and images of the canal surfaces were scanned. The remaining areas of filling material were measured (Image Tool 3.0), and data was analyzed statistically (Kruskal-Wallis and Dunn tests). The time required for filling removal in each group was also recorded (one-way ANOVA and Tukey's HSD test). RESULTS: All groups presented remnants of filling material; PTU had the smallest amount and HF group presented the highest mean value (P< 0.05) in all the thirds. The cervical third had the smallest amount of material when compared with the other thirds (P< 0.05). HF group required a longer mean time, presenting significant difference (P< 0.05). CONCLUSION: Considering the time required and the amount of the filling removal, ProTaper Retreatment were not superior to ProTaper Universal, but both rotary instruments were more effective and less time-consuming than Hedström manual files.