Effect of Obturation Techniques on the Quality of Root Canal Fillings: A Systematic Review and Meta-analysis of in Vitro Studies.

Introduction: The current study aimed to compare the quality of root canal obturation performed with cold lateral condensation with other obturation techniques. Materials and Methods: Diverse Search was conducted using six electronic/academic databases following PICOS (i.e. population, intervention, control, outcomes, and study design) strategy: (P) Extracted mature permanent teeth; (I) Obturation techniques except for cold lateral condensation; (C) Cold lateral condensation tyechnique; (O) Quality of root canal obturation; and (S) In vitro studies assessing parameters using micro-computed tomography. The statistical method used for the meta-analyses was the "inverse variance DerSimonian-Laird test". The heterogeneity data was calculated using the T2, Cochran Q test, and I2 statistics. Results: Fifteen studies were included for the final analysis; one had a low risk of bias, eight a moderate risk, and six a high risk of bias. Ten studies were selected for meta-analyses; three studies comparing cold lateral condensation with carrier-based gutta-percha techniques [P=0.96; mean difference (MD)=-0.02; confidence interval (CI): (-0.77, 0.73); I2=21%]; three comparing cold lateral condensation with single-cone techniques [P=0.75; MD=-0.39; CI: (-2.77, 1.99); I2=92%]; two comparing cold lateral condensation and thermo-plasticized injectable techniques [P=0.37; MD=5.91; CI: (-7.13,18.94); I2=99%]; and five comparing cold lateral condensation with warm vertical condensation techniques [P<0.0001; MD=5.29; CI=(2.84, 7.74); I2=92%]. The overall effect reported significant results [P=0.0003; MD=2.69; CI=(1.23, 4.16); I2=96%]; favoring fewer voids and gaps for the other used obturation techniques. Conclusions: Cold lateral condensation and single-cone techniques presented no statistical differences. Nonetheless, Warm vertical condensation technique had better results compared to cold lateral condensation.

Pharmacological Management of Anxiety on Pain Occurrence During Root Canal Treatment: A Systematic Review.

OBJECTIVE: To answer the question: 'Does the pharmacological management of dental anxiety influence pain occurrence during root canal treatment?' METHODS: Searches on MEDLINE/PubMed, Cochrane Library, Web of Science, Scopus, EMBASE and Open Grey were conducted until September 02, 2022. Only randomised clinical trials were included. The Cochrane risk of bias tool for randomized trials (RoB 2) was used. The overall quality of evidence was assessed through the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) tool. RESULTS: Initial screening resulted in 811 studies. Three hundred seventy-three were excluded for being duplicates. Of 438 eligible papers, ten studies met the inclusion criteria and were selected for full-text reading. Four studies were included in the final analysis. Three studies had a low risk of bias, and one was a high risk. GRADE demonstrated a low quality of evidence. CONCLUSION: There is insufficient evidence to determine whether the pharmacological control of anxiety can influence intraoperative pain occurrence. (EEJ-2022-08-096).

Tratamento Endodôntico de Dente com Calcificação Radicular Pós-Trauma: Relato de Caso Clínico / Endodontic Treatment Of Teeth With Post-Trauma Root Calcification: Case Report

A calcificação do canal radicular é um processo que pode ocorrer posteriormente a um traumatismo dentário ou que pode se desenvolver lentamente em decorrência do envelhecimento dentário fisiológico. É caracterizada pela deposição de tecido duro tanto na câmara pulpar como no canal radicular. Essa condição pode ser diagnosticada através de radiografias periapicais e tomografia computadorizada. Em alguns casos, pode estar associada à necrose pulpar e presença de lesão periapical, e o tratamento pode ser considerado bastante complexo. Este relato de caso clínico aborda o tratamento endodôntico do elemento 21, sintomático, com obliteração do canal radicular e necrose pulpar como sequela de um traumatismo dentário. Após a realização de todos os exames, foi dado o diagnóstico de periodontite apical crônica, sendo proposto o tratamento endodôntico convencional. A maior dificuldade encontrada foi a localização da entrada do canal radicular. Inúmeras radiografias foram realizadas a fim de evitar desvios. Somente ao final do terço médio foi possível localizar a entrada do canal radicular e dar prosseguimento ao tratamento, utilizando a técnica coroa-ápice e medicação intracanal à base de hidróxido de cálcio durante as sessões. Foi possível realizar a obturação do canal radicular quando a paciente se mostrou assintomática. Obteve-se sucesso na realização da técnica, e, após a conclusão do caso, foi possível observar remissão dos sintomas. Após um período de acompanhamento de 6 meses e, posteriormente, de 3 anos, foi possível observar cicatrização dos tecidos periapicais

The calcification of the root canal is a process that may occur after a dental trauma or slowly develop due to physiological dental aging. It is characterized by hard tissue deposition on both the pulp chamber and the root canal. Periapical radiography and computed tomography can be used to diagnose this condition. In some cases, it may be associated with pulp necrosis and the presence of periapical injury, and the treatment may be considered to be quite complex. This case report addresses the endodontic treatment of the central incisor, symptomatic, with root canal obliteration and pulp necrosis as a sequela of dental trauma. After all the tests, chronic apical periodontitis was diagnosed, and conventional endodontic treatment was proposed. The most significant difficulty faced was when locating the root canal's entrance. Numerous radiographs were carried out to avoid deviations. The opening of the root canal could only be found at the end of the middle third, so treatment could proceed by using the crown- down technique and intracanal medication based on calcium hydroxide during the sessions. When the patient was asymptomatic, the root canal has been filled. The accomplishment of the technique was successful, and after finishing the case, there was remission of symptoms. After a six-month follow-up period and three years, the healing of the periapical tissues was observed.

Effect of ultrasonic activation of the adhesive system on dentin tubule penetration and the pushout bond strength of fiber posts.

STATEMENT OF PROBLEM: Whether ultrasonic activation of the adhesive system improves dentin tubule penetration and the bond strength of fiber posts to root dentin is unclear. PURPOSE: The purpose of this in vitro study was to evaluate the effect of ultrasonic activation of 2 adhesive systems (etch-and-rinse and self-etch) and 1 glass ionomer cement on the dentin tubule penetration and pushout bond strength of fiber posts to root dentin. MATERIAL AND METHODS: Sixty maxillary central incisors were endodontically treated and divided into 6 groups (n=10) as per the post cementation strategy: etch-and-rinse, etch-and-rinse and ultrasonic, self-etch, self-etch and ultrasonic, glass ionomer cement, and glass ionomer cement and ultrasonic. The primers, the adhesives, and the glass ionomer cement were activated for 20 seconds each, and the fiber posts were cemented with a resin cement. Dentin tubule penetration was evaluated by confocal laser scanning microscopy and the pushout bond strength measured at 3 post locations: cervical, middle, and apical. The failure patterns were also described after pushout testing. RESULTS: Self-etch and ultrasonic showed higher dentin tubule penetration than the other cementation strategies (P<.05) and improved the bond strength values (P<.05), which were higher than etch-and-rinse and ultrasonic and glass ionomer cement and ultrasonic (P<.05). Adhesive failures at the cement and dentin interface were predominant in the etch-and-rinse, self-etch, and self-etch and ultrasonic groups. CONCLUSIONS: Ultrasonic activation improved the dentin tubule penetration of a self-etch adhesive system. The bond strength of fiber posts cemented with a self-etch adhesive system and a resin cement was improved after ultrasonic activation.

Impact of Nonsurgical Treatment of Asymptomatic Apical Periodontitis on the Oral Health-related Quality of Life: A Prospective Study.

Introduction: The aim of this study was to evaluate the impact of nonsurgical root canal treatment (nRCT) and the healing of asymptomatic apical periodontitis (AAP) on the oral health-related quality of life (OHRQoL) in a Brazilian population. Materials and Methods: This prospective longitudinal observational study included 56 adults, in which 84 teeth with asymptomatic apical periodontitis underwent nonsurgical root canal treatment. Socio-demographic and medical data were collected; the primary outcome oral health-related quality of life was measured by the short form of the Oral Health Impact Profile (OHIP-14). Statistical analysis was carried out by Mann-Whitney U-test, and changes in the oral health-related quality of life scores post-treatment were estimated by Student t-test. Results: The mean age was 51.0±15.2 years, with 53.5% of females. Overall, nRCT significantly improved the OHRQoL (P<0.001, effect size=0.76). Gender (female) was associated with a higher OHRQoL after nRCT (P<0.05). OHIP-14 showed a significant reduction six months after root canal treatment compared to baseline scores. Conclusion: Present findings revealed that nonsurgical root canal treatment improved the oral health-related quality of life in patients with asymptomatic apical periodontitis.

Effect of A Clinical-Replicable Cooling Protocol on the Cyclic Fatigue Resistance of Heat-Treated Nickel-Titanium Instruments.

Introduction: The aim of this study was to evaluate the bending and cyclic fatigue resistance of Wave One Gold (WOG) and X1 Blue (X1B) instruments when tested at body temperature (36°C ± 1°C) with and without subjected to an alloy cooling protocol. Materials and Methods: A total of sixty instruments (n=30) were tested. Forty instruments (n=20) were randomly selected and divided into two groups: body temperature (BT; n=20) and body temperature with cooling protocol (CP; n=20). Cyclic fatigue test was performed until fracture in a conventional stainless-steel device with water bath equipment to simulate body temperature. CP group instruments were subjected to 5 seconds of spray cooling every 30 seconds. Time to fracture was recorded in seconds. Resistance to bending at an angle of 45 degrees was evaluated using twenty instruments (n=10). Fractured surfaces were examined under scanning electron microscopy (SEM). Statistical analysis was performed at a 5% significance level. Results: There was no difference in the cyclic fatigue resistance between instruments in BT groups (P>0.05). Cooling protocol significantly increased the cyclic fatigue resistance of X1B instruments (P=0.0003) and WOG instruments (P=0.0003). Results: WOG instruments had a significantly lower cyclic fatigue resistance compared to X1B instruments in CP group (P=0.0001). There were no significant differences between the values of resistance increase presented by the instruments after cooling (P>0.05). Bending test presented no statistically significant differences between the tested instruments (P>0.05). Both instruments in both groups showed typical features of cyclic fatigue behavior under SEM. Conclusions: X1 Blue #25.06 and WaveOne Gold #25.07 instruments presented similar cyclic fatigue resistance. The investigated clinical-replicable cooling protocol improved the cyclic fatigue resistance of the tested instruments, with X1 Blue #25.06 presenting a greater cyclic fatigue resistance after cooling. Both instruments presented a similar bending capacity.

Effect of Irrigating Agitation after Root End Preparation on the Wall Cleaning and Bond Strength of Calcium Silicate Material in Retrograde Obturation.

OBJECTIVE: This study aimed to evaluate the cleaning efficacy of irrigant activation with a new ultrasonic tip in root-end preparations and to determine its influence on the bond strength of calcium silicate-based material. MATERIALS AND METHODS: Maxillary canines were prepared and filled, and their root ends resected. Root-end cavities were ultrasonically prepared and randomly distributed into four groups according to the final irrigation protocols: G1 (ultrasonic irrigation [UI] + saline solution [SS]), G2 (syringe irrigation [SI] + SS), G3 (UI + ethylenediaminetetraacetic acid [EDTA]), and G4 (SI + EDTA). Cleaning efficacy analysis employed 72 specimens (n = 18) split longitudinally for imaging of the same areas by scanning electron microscopy (SEM). The percentage of dentinal tubules opened before and after irrigation was used as evaluation parameter. Push-out testing employed 40 specimens (n = 10) sectioned apical region perpendicularly, which slice was placed on a testing machine for the bond strength measurement and failure mode was assessed by SEM. The data were statistically analyzed (α ≤ 0.05). RESULTS: G3 (UI + EDTA) removed the smear layer more effectively, showed the best tubule opening (p < 0.05), and presented the highest mean bond strength values (p < 0.05). Failure modes were predominantly adhesive, except for the G3 (UI + EDTA) group, in which they were mainly mixed (80%). CONCLUSION: The results of this study suggest that EDTA 17% agitation promoted better cleaning and smear layer removal, improving the push-out bond strength of calcium silicate material in retrograde obturation.

Comparisons by microcomputed tomography of the efficiency of different irrigation techniques for removing dentinal debris from artificial grooves.

AIM: The aim of this study was compare the capacity of different irrigation protocols for debris removal from artificial grooves and assess the effectiveness of Easy Clean used in different kinematics by means of micro-CT. METHODOLOGY: Fifty acrylic prototyped maxillary incisors were instrumented and included in a muffle. The specimens were longitudinally sectioned, and a longitudinal groove was made on the inner surface of the root canal in one of hemisections, and the dentin debris was inserted into the grooves. The specimens were divided into five groups (n = 10): G1: Conventional with open-ended needle; G2: Conventional with double side-vented needle; G3: Easy Clean in reciprocating movement; G4: Easy clean in continuous rotation (ECCR); and G5: Passive ultrasonic irrigation (PUI). All specimens were scanned using microcomputed tomography before and after the irrigation technique and calculated the volume (mm3) of dentin debris. The paired t-test and post hoc Tukey test were the statistical tests used, with significance set at 5%. RESULTS: There were no significant difference (P > 0.05) between PUI and ECCR. ECCR was significantly (P < 0.05) more effective than the groups of conventional irrigation techniques. CONCLUSIONS: PUI and ECCR favored the removal of a larger volume of dentin debris from the groove.

Influence of operating microscope in the sealing of cervical perforations.

CONTEXT: Accidental root canal perforations are among the main complications of endodontic treatment. AIM: This study evaluated the influence of operating microscope (OM) in the marginal adaptation of mineral trioxide aggregate (MTA) (Angelus(®)) and glass ionomer (Vitremer) inserted into cervical perforations. MATERIALS AND METHODS: Perforations were made in the cervical third of the buccal wall of the root canal in mandibular incisors. Next, the teeth were divided into four groups (N = 10): MG - MTA without OM; VG - Vitremer without OM; MOMG - MTA with OM; VOMG - Vitremer with OM. The perforations were sealed according to the group and the teeth were prepared for analysis by confocal laser scanning microscope. Images of perforation region (1,024×) were made and the gap presented by the materials was measured using the Image J program. LEXT OLS4100 three dimensional (3D) measuring laser microscope measured the volumetric misfit. Data of gap were analyzed by Kruskal-Wallis and Dunn's tests. Analysis of variance (ANOVA) and Tukey's tests compared the volumetric misfits. RESULTS: The results showed lower volume and gap in the interface dentin/material in VOMG compared to the other groups (P < 0.05). CONCLUSION: The use of OM improved the quality of cervical perforations sealed with Vitremer, being indicated in clinical situations of iatrogenic cervical perforations.

Effectiveness of final irrigant protocols for debris removal from simulated canal irregularities.

INTRODUCTION: The aim of this in vitro study was to compare the effectiveness of saline, 2.5% sodium hypochlorite, and 2% chlorhexidine, with or without passive ultrasonic irrigation (PUI), in debris removal from simulated canal irregularities within prepared root canals. METHODS: Ninety bovine lateral incisors were randomly divided into 3 main groups (n = 30) based on the irrigant and prepared with hand files attached to an oscillating handpiece (NSK, Tokyo, Japan) up to a size #80 K-file. Next, the teeth were split longitudinally, and a standardized groove was prepared into the apical third and filled with dentin debris. After the halves were reassembled, they were placed in a muffle. Each main group was randomly subdivided into 2 groups (n = 14) and was treated with different final irrigation protocols. In the sodium hypochlorite/PUI, chlorhexidine/PUI, and saline/PUI groups, the solution was ultrasonically activated 3 times for 20 seconds. In the remaining groups, PUI was not performed. Specimens were scored for debris removal and analyzed under a scanning electron microscope. RESULTS: An association was observed between the score of debris removal and protocols using PUI (P < .05). No association was observed between the scores of debris removal and the irrigants (P = .87). CONCLUSIONS: Final irrigation protocols that used PUI were more effective in removing debris from simulated canal irregularities into the apical third than those that did not use it.

Calcium hydroxide fillings in curved canals: influence of apical enlargement using the rotary systems ProTaper, K3, and two hand instrumentation techniques / Preenchimento de canais curvos com hidróxido de cálcio: influência do alargamento apical usando os sistemas rotatórios ProTaper, K3 e duas técnicas de instrumentação manual

Objective: This study aimed to analyze the influence of the instrumentation technique (hand or rotary), and apical enlargement on calcium hydroxide (CH) fillings in cur-ved canals. Materials and method: One hundred and ten simulated root canals were divided into eleven experi-mental groups (G). Canals were prepared with K-Flexofile hand instruments, using either crown-down (GCD 25, GCD 30 and GCD 35) or step-back (GSB 25, GSB 30 and GSB 35) techniques; and with rotary instruments, using either ProTaper (GPT F1 and GPT F2) or K3 (GK3 25, GK3 30 and GK3 35) systems. The apical diameter correspon-ded to 0.20 mm (GPT F1), 0.25 mm (GCD 25, GSB 25, GPT F2 and GK3 25), 0.30 mm (GCD 30, GSB 30, GK3 30), and 0.35 mm (GCD 35, GSB 35, GK3 35). A CH pas-te, previously colored with blue Indian ink, was injected into the canals using a special syringe. The four sides of the blocks with simulated canals were scanned and the images were transferred to the AutoCAD-2008 software, for assessing the amount (%) of filling in the apical 5 mm (ANOVA; Tukey?s Test; ?=0.05). Qualitative analysis was also performed regarding the presence or absence of voids (Chi-square Test; ?=0.05). Results: In GSB, there was significant difference between diameters 25 and 30. GSB showed lower amount of filling (P<0.05) than GK3, when the apical diameter corresponded to 0.30 mm. GCD showed lower amount of filling (P<0.05) than the other groups (SB, PT, and K3), when the apical diameter corresponded to 0.25 mm. No significant difference was detected when comparing the four sides of the blocks. Conclusion: Preparation technique and apical diameter had slight or no relevant influence on CH paste filling in simulated curved root canals. Statistical differences found in this study may be clinically irrelevant, since the amount of filling, regardless of preparation technique and apical diameter, was very close or equal to 100%.

Resistência ao deslocamento de quatro materiais retrobturadores à dentina bovina e humana / Bond strength of four root-end filling materials to bovine and human root dentin

Objetivo: O objetivo desse trabalho foi comparar a resis-tência ao deslocamento de quatro cimentos endodônti-cos utilizados para o selamento de retrocavidades (Por-tland, MTA, Super EBA® e Sealapex®) em dentina bovinae humana. Materiais e método: Quarenta raízes bovinase quarenta raízes distais de molares inferiores humanosforam apicetomizadas e cavidades retrógradas forampreparadas. As raízes foram divididas aleatoriamente emquatro grupos e preenchidas com os materiais retrobtu-radores testados. Após uma semana, as raízes foram sec-cionadas transversalmente e os slices foram submetidosao teste de push-out. Os padrões de falha foram analisa-dos em microscopia óptica (10×) e classificados como:adesiva, coesiva do cimento, coesiva da dentina e mista.Os dados foram analisados utilizando o teste de Kruskal--Wallis, Mann-Whitney e Dunn. Resultados: Os maioresvalores de resistência ao deslocamento foram obtidosem dentina bovina (P < 0,05). O cimento Portland eMTA apresentaram os maiores valores de resistência aodeslocamento quando comparados com Super EBA® eSealapex®. Falha coesiva de cimento foi predominanteindependentemente do cimento e do substrato. Conclu-são: Pode-se concluir que a resistência ao deslocamentodos materiais retrobturadores é dependente do tipo decimento utilizado e substrato analisado.

Push-out bond strengths of different dental cements used to cement glass fiber posts.

STATEMENT OF PROBLEM: Since the introduction of glass fiber posts, irreversible vertical root fractures have become a rare occurrence; however, adhesive failure has become the primary failure mode. PURPOSE: The purpose of this study was to evaluate the push-out bond strength of glass fiber posts cemented with different luting agents on 3 segments of the root. MATERIAL AND METHODS: Eighty human maxillary canines with similar root lengths were randomly divided into 8 groups (n=10) according to the cement assessed (Rely X luting, Luting and Lining, Ketac Cem, Rely X ARC, Biscem, Duo-link, Rely X U100, and Variolink II). After standardized post space preparation, the root dentin was pretreated for dual-polymerizing resin cements and untreated for the other cements. The mixed luting cement paste was inserted into post spaces with a spiral file and applied to the post surface that was seated into the canal. After 7 days, the teeth were sectioned perpendicular to their long axis into 1-mm-thick sections. The push-out test was performed at a speed of 0.5 mm/min until extrusion of the post occurred. The results were evaluated by 2-way ANOVA and the all pairwise multiple comparison procedures (Tukey test) (α=.05). RESULTS: ANOVA showed that the type of interaction between cement and root location significantly influenced the push-out strength (P<.05). The highest push-out strength results with root location were obtained with Luting and Lining (S3) (19.5 ±4.9 MPa), Ketac Cem (S2) (18.6 ±5.5 MPa), and Luting and Lining (S1) (18.0 ±7.6 MPa). The lowest mean values were recorded with Variolink II (S1) (4.6 ±4.0 MPa), Variolink II (S2) (1.6 ±1.5 MPa), and Rely X ARC (S3) (0.9 ±1.1 MPa). CONCLUSIONS: Self-adhesive cements and glass ionomer cements showed significantly higher values compared to dual-polymerizing resin cements. In all root segments, dual-polymerizing resin cements provided significantly lower bond strength. Significant differences among root segments were found only for Duo-link cement.

Effect of final irrigation protocols on microhardness and erosion of root canal dentin.

The aim of this study was to evaluate the effect of final irrigation protocols (17% EDTA, BioPure MTAD, SmearClear, and QMiX) on microhardness and erosion of root canal dentin. Fifty roots were sectioned transversely at the cement-enamel junction and each root was sectioned horizontally into 4-mm-thick slices. The samples were divided into five groups (n = 10) according to the final irrigation protocol: G1: distilled water (control group); G2: 17% EDTA; G3: BioPure MTAD; G4: SmearClear; and G5: QMiX. The dentin microhardness was then measured with a load of 25 g for 10 s. Initially, the reference microhardness values were obtained for the samples without any etching. The same samples were then submitted to the final irrigation protocols. A new measure was realized and the difference between before and after the procedures was the dentin microhardness reduction. In sequence, the specimens were submitted to SEM analysis to verify the dentinal erosion. The Kruskal Wallis and Dunn tests (α = 5%) were used to compare the results. The dentin microhardness decreased for all final irrigation protocols. There was no significant difference between groups 2, 3, 4, and 5 (P > 0.05), but this groups presented significant dentin microhardness reduction than G1 (P < 0.05). In G2, occurred the highest incidence of dentinal erosion (P < 0.05). 17% EDTA, BioPure MTAD, SmearClear, and QMiX promoted significant dentin microhardness reduction. Dentinal tubules erosion was promoted by 17% EDTA.

Apical resorption in teeth with periapical lesions: correlation between radiographic diagnosis and SEM examination.

This study correlated the radiographic findings and scanning electron microscopy (SEM) images of external apical resorption (EAR) in teeth with periapical lesions. Standard radiographs were taken from 45 teeth with periapical lesions before their extraction. Using a radiographic examination, the root apex of each tooth was classified according to the EAR into the following categories: radiographic external apical resorption (REAR) absent, superficial and deep. The apical root surface was also examined with SEM. Photomicrographs of EARs were classified as periforaminal (PEAR) and foraminal (FEAR) in three degrees: 0, 1 and 2. REAR was present in 72.5% of cases, of which 20% were deep. Based upon SEM analysis, PEAR and FEAR occurred in 75.6% and 66.7% of cases respectively; 51.2% and 59% respectively, of these teeth received a score of 2. Only 15.4% of the specimens were unaffected by EAR. When teeth with periapical lesions were examined for EAR with both radiography and by SEM, there was no correlation between the findings.

Effects of four instruments on coronal pre-enlargement by using cone beam computed tomography.

INTRODUCTION: This ex vivo study used cone beam computed tomography to evaluate the amount of dentin removal from the distal wall of the mesial canal of human mandibular first molars caused by 4 instruments used to flare the cervical third. METHODS: Thirty-two mesial roots were divided into 4 groups prepared by using ProTaper, K3, Gates-Glidden, or LA Axxess. The dentin thickness of the distal cervical wall of mesial canals was measured before and after the preparation by using computed tomography and Adobe Photoshop software. RESULTS: There was no statistically significant difference between the study groups (P > 05). CONCLUSIONS: All the instruments used for cervical preparation seemed to be safe and did not damage the dentin structure of the distal wall of mesial root canals of mandibular molars.