Uniradicular Teeth Research Articles

The effect of endodontic instrumentation on fatigue, fracture load, and dentin crack formation in restored uniradicular teeth: in vitro study

Objective(s): The aim of this study was to evaluate the effect of manual, rotatory, and reciprocating endodontic instrumentation for uniradicular teeth on fatigue, load to failure, and dentin crack formation. Materials and Methods: Sixty-two human uniradicular teeth were selected. Root samples were standsdized at 14 mm (t0). Teeth were divided into three groups according to endodontic instrumentation: Manual (M), Rotatory (RT), or Reciprocating (RC) and filled with passive technique (t1). All teeth received the cementation of a glass fiber post and were restored with composite resin core (t2) and metallic crown. Samples were subjected to mechanical cycling (177 N, 2x106 cycles, 4 Hz) (t3), followed by a load to failure test. Failure analysis was performed and dentin crack analysis was conducted in two samples each time t0, t1, t2, and t3. Results: Load to failure was not different between groups (p=0.716). However, the M group presented more irreparable failures. M and RC groups presented a high percentage of root sections with defects, and t3 was the evaluation time which presented more dentin crack formation. Conclusion(s): Endodontic instrumentation system did not affect load to failure of uniradicular teeth. Still, it affected the failure mode, with manual and reciprocating instrumentations presenting more irreparable failures and high root dentin crack formation.

In Vitro Evaluation of Push-Out Bond Strength in Three Different Post Systems

Background and objectives: Intimate adaptation to the canal walls is accomplished by custom-made posts which leave an even thickness of cement layer. Therefore, this study has been conducted for assessing the strength of push-out bond among prefabricated fiber posts, relined fiberglass posts, and zirconium posts using resin cement of self-adhesive and adhesive. The mode of failure was also assessed. Materials and Methods: Sixty uniradicular teeth were endodontically treated. According to the kind of post system and cement utilized (n=10), the specimens were separated randomly into six groups. Zirconium oxide post, customized glass fiber post, and glass fiber post were used. The roots were divided into three discs: apical, middle, and cervical sections. After that, the discs were put through a push-out test, and the fracture mode was examined using a stereomicroscopic loupe. Results: The highest push-out value was recorded for the relined post (8±2.83 MPa), and the lowest was registered with no significant differences for the prefabricated post (7.27±3.76 MPa). There were no significant differences in strength bond across the various posts and root regions (P?.05). Adhesive failure at the dentin-cement interfaces for the prefabricated and relined post was (60, 57) % respectively, and zirconium oxide post was (22%). Conclusions: Relined posts may be a suitable clinical situation as a post material selection with reduced clinical steps. When posts are joined using self-adhesive and adhesive resin cement, the root region has no important influence on the strength of the bond.

In vitro assessment of antimicrobial potential of low molecular weight chitosan and its ability to mechanically reinforce and control endogenous proteolytic activity of dentine.

Chitosan-based biomaterials exhibit several properties of biological interest for endodontic treatment. Herein, a low molecular weight chitosan (CH) solution was tested for its antimicrobial activity against Enterococcus faecalis (E. faecalis) and effects on dentine structure. The root canal of 27 extracted uniradicular teeth were biomechanically prepared, inoculated with a suspension of E. faecalis and randomly assigned to be irrigated with either 5.25% sodium hypochlorite (NaClO), 0.2% CH or sterile ultrapure water (W). Bacteriologic samples were collected from root canals and quantified for of E. faecalis colony-forming units (CFUs). The effectiveness of CH over E. faecalis biofilms was further measured using the MBEC Assay®. Additionally, dentine beams and dentine powder were obtained, respectively, from crowns and roots of 20 extracted third molars. Dentine samples were treated or not with 17% EDTA and immersed in either CH or W for 1 min. The effects of CH on dentine structure were evaluated by assessment of the modulus of elasticity, endogenous proteolytic activity and biochemical modifications. The number of E. faecalis CFUs was significantly lower for samples irrigated with CH and NaClO. No significant differences were found between CH and NaClO treatments. Higher modulus of elasticity and lower proteolytic activity were reported for dentine CH-treated specimens. Chemical interaction between CH and dentine was observed for samples treated or not with EDTA. Present findings suggest that CH could be used as an irrigant during root canal treatment with the triple benefit of reducing bacterial activity, mechanically reinforcing dentine and inhibiting dentine proteolytic activity.

Antimicrobial Effect of German chamomile Extractas Root Canal Irrigant (in vitro Study)

Aims: To evaluate the antimicrobial effect of German chamomile extract as a root canal irrigant in vitro, and comparing its effect with chlorhexidine 0.2% irrigant solution.
 Materials and Methods: Twenty adult patients with age range 18-40 years attending dental school with symptomatic uniradicular teeth with necrotic pulp diagnosed by radiograph with no fistula or sinus tract were chosen; 10 subjects for each irrigant solution (the test and the control groups). Microbiological samples were obtained from the root canal at the beginning of the first appointment, and then moistened paper point is placed in a screw capped vial containing 5 ml Thioglycolate broth for anacrobic bacteria and the other containing Brain Heart Infusion broth for aerobic bacteria, which is incubated directly for 18 hours at 37 °C. Turbidity test was used to compare antimicrobial effect of German chamomile extract with chlorhexidine 0.2%.
 Results: Mean reduction in bacterial count (0.36 + 0.09 for acrobic and 0.19 + 0.02 for anacrobic) for German chamomile and chlorhexidine 0.2% (0.084 + 0.03 and 0.052 + 0.016 respectively) were determined by using onc sample t-test, which was much lower for German chamomile than for chlorhexidine 0.2% with significant difference. For comparison between two materials for acrobic and anacrobic, unpaired t-test was used. Results were considered significant at p < 0.05.
 Conclusion: German chamomile extract is effective antimicrobial irrigant solution especially on anaerobic bacteria but much lower than chlorhexidine 0.2% irrigant solution.

Depth of cure of bulk-fill and flowable resin in contact with mineral trioxide aggregate plugs in ex vivo immature teeth

Introducción: Tooth development may be interrupted when the pulp becomes necrotic because of caries, trauma, or anatomical alterations such as dens evaginatus.Objective: To determine the depth of cure and hardness of an injected bulk-fill resin (Sonic Fill™) compared with a flowable resin (Revolution™) in teeth with incomplete apex formation.Material and Methods: Forty recently extracted uniradicular teeth were assigned for the study; 3 mm of the apex was cut to standardize all teeth to 13 mm, then the root canals were instrumented to a size 1.10 mm by using Peeso drills. A 3-mm mineral trioxide aggregate (MTA) plug was placed in the apical third. After etching the root canal walls, an intracanal adhesive system was placed and cured. Then, Sonic Fill™ was injected into the remainder of the root canal of 20 specimens randomly selected and a flowable composite resin (Revolution™) was placed in the others. All specimens were placed in a rectangular, acrylic base and sectioned along the long axis of the tooth. The depth of cure and hardness of the composite resin were evaluated using the Vickers micro-hardness test and compared with Student T test for independent groups.Result: Specimens in the SF group showed significantly (p = 1.6 × 10−6) higher Vickers micro-hardness (24.03±4.09 Kp) I.C.95% [20.88- 27.19] than those in the Revolution™ composite group (11.28±3.19 Kp) I.C.95% [8.82- 13.72].Conclusions: Specimens in the SonicFill™ group showed significantly higher Vickers microhardness than those in the flow able resin group, making the former more suitable for strengthening teeth with immature apexes.

Efficient removal of 2,6-xylidine precipitate using different agitation protocols: An in vitro field emission scanning electron microscopic study.

Background:Any solution of chemical nature when combined will result in the formation of a precipitate, which in the root canal system will interfere with the hermetic seal. In clinical practice presence of any precipitate, especially carcinogenic in nature, should be eliminated.Aim:To evaluate whether final irrigation with different agitation protocols will remove the precipitate formed following lidocaine hydrochloride and sodium hypochlorite combination at the coronal, middle, and apical-root thirds.Materials and Methods:Forty-four uniradicular teeth were standardized at 17 mm. All specimens were injected with 2% lidocaine hydrochloride and 2.5% sodium hypochlorite, followed by mechanical instrumentation using rotary files. Further, specimens were arbitrarily divided into four groups (n = 11) based on the final irrigation protocol: Group 1: No irrigation; Group 2: Manual irrigation; Group 3: Mechanical irrigation; Group 4: Ultrasonic irrigation. Samples were sectioned and Field Field Emission Scanning Electron Microscopic (FESEM) analysis of the canal wall was done at coronal, middle, and apical thirds.Results:FESEM images revealed occluded dentinal tubules with the presence of precipitate seen in all-thirds of each specimen.Conclusion:No irrigation protocol was successful in removing the precipitate formed; but when compared ultrasonic irrigation had the least precipitate seen at-coronal,-middle and apical thirds.

Comparison of Antibacterial Effects of Photodynamic Therapy and an Irrigation Activation System on Root Canals Infected With Enterococcus faecalis: An In Vitro Study.

Introduction: Enterococcus faecalis is a resistant bacterium which is the most abundant species in infected root canals. Photodynamic therapy (PDT) is a method for killing the bacteria with active Oxygen radicals generated in a photosensitizer when exposed to centralized light. Furthermore, as a new method of canal disinfection, a variety of irrigation activation systems have been introduced, one of which is GentleFile (GF) with rotary movements and spiral effects for antibacterial action. This study aimed to compare the effectiveness of the two mentioned methods when used with and without Sodium Hypochlorite in eliminating E. faecalis from infected root canals. Methods: Fifty-eight uniradicular teeth were randomly divided into 4 experimental groups of 14. Two specimens were selected for later scanning electron microscopy in order to screen the procedure steps. In each experimental group, 10 samples were selected to be treated with GF or PDT; 3 of them were selected as positive controls and the other one sample was chosen as a negative control. Experimental groups were as follows: (1) Irrigation activation system, (2) Irrigation activation system + sodium hypochlorite, (3) PDT, and (4) PDT+ sodium hypochlorite. The specimens were then cultured for a bacterial colony count. Results: The decrease in the bacterial count after the treatment with the irrigation activation system was 99.8% (P =0.011) and when the system was used with sodium hypochlorite, it was 100% (P =0.001). The antibacterial effect of PDT was 90.08% (P =0.011) and it was 99.7% when PDT was combined with sodium hypochlorite (P =0.011). Conclusion: All four methods can be administered as complementary methods in root canal disinfection. According to the results of disinfection in the experimental groups of current study it is concluded that integration of new technologies such as activation irrigation system or PDT in Combination with NaOCl ameliorates disinfection of root canal and can provide several advantages in the endodontic outcome.

In Vivo Evaluation of Painful Symptomatology after Endodontic Treatment Performed Using Two Different Irrigation Needle Insertion Depths

Objective The main purpose of this study was to evaluate pain symptoms in patients after endodontic treatment performed in a single session in teeth with vitality or pulp necrosis, comparing two depths of insertion of the NaviTip irrigation needle. Materials and Methods One-hundred upper uniradicular teeth were selected and divided into four groups ( n = 25), namely Bio group 1 (live pulp/1 mm from the foramen), Bio group 3 (live pulp/3 mm from the foramen), Necro group 1 (pulp necrosis/1 mm from the foramen), and Necro group 3 (pulp necrosis/3 mm from the foramen). All canals were instrumented with Wave One Gold System. Irrigation was performed using 2.5% NaOCl. The teeth were filled using the single-cone technique with AH Plus sealer using a McSpadden compactor. After treatment, patients answered a questionnaire with a visual analog scale scored from 0 to 10 at 1, 3, and 7 days after treatment. Statistical Analysis Data were analyzed using Mann–Whitney U, Wilcoxon, and Friedman tests. Results There was a decrease in average pain levels at the three time points for both vital and necrotic teeth ( p < 0.05). There were no significant differences in postoperative pain levels comparing needle depth, or vitality and pulp necrosis ( p > 0.05). The percentage of mild pain increased over time and moderate pain decreased, regardless of pulp condition. There was no incidence of acute pain at any time. Conclusions Post-treatment endodontic pain levels in upper uniradicular teeth with or without pulp vitality resulted in similar pain scores, regardless of the depth of insertion of the irrigation needle in relation to the apical foramen.

Antimicrobial efficacy of photodynamic therapy, diode laser, and sodium hypochlorite and their combinations on endodontic pathogens.

Sterilization of the root canal system is of prime importance for a successful root canal therapy. Lasers and photodynamic therapy (PDT) have become the latest choice to eradicate microorganisms in the root canal. To evaluate and compare the antimicrobial activity of diode laser, photodynamic therapy, and sodium hypochlorite along with their combinations on endodontic pathogens: Enterococcus faecalis and Streptococcus mutans. A total of 120 uniradicular teeth were stored in 5.2% NaOCl solution to remove organic residues and the crowns were sectioned at the cemento-enamel junction (CEJ) to obtain root canal length of 15 mm. Canals were shaped using step-back technique up to #40 K-file and were autoclaved. The selected teeth (specimen) were randomly divided into two equal groups with sixty teeth being inoculated with E. faecalis (Group E) and remaining sixty teeth with S. mutans (Group S). Further, the groups were subdivided according to the disinfection technique used. Ten teeth from each subgroup were disinfected with a diode laser, photo activated disinfection (PAD), sodium hypochlorite, a combination of sodium hypochlorite and diode laser, a combination of sodium hypochlorite and photo activated disinfection respectively. Ten teeth in each group served as control without any disinfection. The treated specimens were transferred to test tubes containing 5 ml sterile Luria Bertani broth, incubated and the bacterial count, optical density in each root specimen was calculated and compared. The pairwise comparison of colonies across the subgroups was done by the Kruskal-Wallis test and within the subgroups was carried out using the Mann-Whitney U test. The statistical implication was tested at 5% and the study was performed using SPSS 18.0 ver. (SPSS Inc.). A significant reduction (98%) in the E. faecalis count was observed when the NaOCl was used in combination with the diode laser or PAD. PAD along with 3% NaOCl presents the advantage of utilizing a lower wavelength laser beam. Hence, PAD in combination with NaOCl can be an alternative and better option for root canal disinfection for both the endodontic pathogens, E. faecalis and S. mutans.

Efficacy of passive ultrasonic irrigation, continuous ultrasonic irrigation versus irrigation with reciprocating activation device in penetration into main and simulated lateral canals.

Context:The use of chemicals solutions and means of activation is of utmost importance in endodontic treatment.Aims:This study compared three activation techniques used in the final irrigation of the endodontic treatment.Subjects and Methods:Eighty uniradicular teeth were instrumented with the Protaper Universal system up to F4 file. After decalcification, the teeth had artificial lateral canals created at 2, 4.5 and 6 mm from working length (WL). The groups were randomly divided into four groups (n = 20): control group (C), passive ultrasonic irrigation (PUI) group, continuous ultrasonic irrigation (CUI) group, and easy clean (EC) group. The penetration of the irrigant into the samples was evaluated using image observation using the Image J program.Statistical Analysis Used:The level of agreement among the observers was determined by the Cronbach's alpha test. The likelihood ratio test was used to evaluate possible differences between the groups and the Kendall's W statistic test to verify possible differences between the irrigant penetration levels in the lateral canals. The Fisher's exact test was applied to verify differences by the studied group considering the WL variables and lateral canals.Results:The results showed no statistical difference in the penetration of the irrigator in the main canal when compared to the C, PUI, CUI, and EC groups (P > 0.05).Conclusions:The method using a positive syringe and needle pressure was not able to effectively carry the irrigator to the artificially made lateral canals, whereas PUI, CUI, and EC were equally efficient in this regard (P < 0.01).

Antimicrobial Photodynamic Therapy Associated with Conventional Endodontic Treatment: A Clinical and Molecular Microbiological Study.

This study evaluated antimicrobial photodynamic therapy (aPDT) as an adjunct to endodontic treatment. Ten uniradicular teeth (control group (CG)=4 (2 and test group (TG)=6) with primary endodontic infections, from both genders, between 17 and 65years old, were analyzed. Microbiological samples were collected before and after chemical-mechanical instrumentation (CMI), after aPDT (for the TG), and after the removal of the temporary restorations (second session). In TG, the aPDT was performed with 100μgmL-1 methylene blue and irradiated with low power laser (InGaAIP, 660nm; 100mW; 40s) with a fiber-coupled optical laser. Another irradiation (3J; 30s; spot size of 3mm2 ) was performed in the gingiva close to the apical foramen. The PCR was performed, after previous whole-genome amplification, for Enterococcus faecalis, Candida genus and Bacteria domain. For TG, a positive tooth for Candida spp. before of the CMI presented negative results in subsequent samples. Additionally, E.faecalis species was present in four samples before CMI, two after CMI, in one after the aPDT and was not detected at the second session. aPDT may be an effective adjunct therapy, resulting in a reduction (P=0.0286) of the incidence of E.faecalis before root canal obturation.

ANÁLISE DO PADRÃO DE FRATURAS EM PINOS ANATOMIZADOS CIMENTADOS COM DIFERENTES AGENTES CIMENTANTES

O objetivo do presente estudo foi investigar, in vitro, o padrão de fratura em dentes com pino de fibra de vidro (PFV) anatomizado e fixado com diferentes agentes cimentantes. Foram utilizados 30 dentes bovinos mandibulares unirradiculares. As raízes foram tratadas endodonticamente e divididas aleatoriamente em dois grupos, de acordo com o agente cimentante utilizado, em G1: cimento resinoso autoadesivo (RelyX U200-3M ESPE); G2: cimento resinoso convencional (Allcem-FGM). Após a anatomização e cimentação dos pinos, os espécimes foram armazenados em estufa, a 37ºC, por sete dias. Em seguida, foi realizada a secção das raízes, sob irrigação constante, obtendo-se de cada raiz seis fatias de 1 mm de espessura, totalizando 180 corpos de prova. O teste de resistência à extrusão (push-out) foi realizado em todos os espécimes, e posteriormente, os corpos de prova foram observados em microscópio ótico de luz, para avaliar os tipos de fratura. O tipo de fratura mais frequente em ambos os grupos foi a coesina em dentina (G1 = 32,2%; G2 = 30%). Observou-se frequência estatisticamente maior de falhas adesivas entre dentina e cimento no grupo G2 (P = 0,007). Além disso, detectou-se frequência estatisticamente mais elevada (P = 0,027) de fratura coesiva em dentina no terço cervical (38,3%) quando comparado ao terço apical (20,0%). Os achados sugerem que o cimento autoadesivo (RelyX U200-3M ESPE) apresentou resultados mais favoráveis quando da análise do padrão de fraturas.

Intracanal Cryotherapy Reduces Postoperative Pain in Teeth with Symptomatic Apical Periodontitis: A Randomized Multicenter Clinical Trial

IntroductionA prospective, multicentered, randomized clinical trial was designed to assess if controlled irrigation with cold saline could result in less incidence and intensity of postoperative pain in patients presenting with pulp necrosis and symptomatic apical periodontitis. MethodsA total of 210 patients (presenting with necrotic uniradicular teeth with a diagnosis of symptomatic apical periodontitis and a preoperative visual analog scale (VAS) score higher than 7) were randomly allocated in the control or experimental group after the completion of shaping and cleaning procedures. The experimental group received a final irrigation with 20 mL sterile cold (2.5°C) saline solution delivered to the working length with a sterile, cold (2.5°C) Endovac microcannula (Kerr Endo, Orange Country, CA) for 5 minutes. The same protocol was used in the control group with room temperature saline solution. Patients were instructed to record the presence, duration and level of postoperative pain, and analgesic medication intake. A logistic regression was used to compare the incidence of postoperative pain and the need for painkillers between groups. Differences in general pain intensity between groups were analyzed using the ordinal (linear) chi-square test. Postoperative pain after 6, 24, and 72 hours (recorded in a VAS scale) and the need for analgesic medication intake between the 2 groups were assessed using the Mann-Whitney U test. ResultsPatients in the control group presented a significantly higher incidence of postoperative pain, intensity, and need for medication intake (P < .05). ConclusionsCryotherapy reduced the incidence of postoperative pain and the need for medication intake in patients presenting with a diagnosis of necrotic pulp and symptomatic apical periodontitis.

Effect of different diode laser wavelengths on root dentin decontamination infected with Enterococcus faecalis

The objective of this study was to evaluate the antibacterial effect and the ultrastructural alterations of diode laser with different wavelengths (808nm and 970nm) and its association with irrigating solutions (2.5% sodium hypochlorite and 2% chlorhexidine) in root dentin contaminated by a five days biofilm. Thirteen uniradicular teeth were sectioned into 100 dentin intraradicular blocks. Initially, the blocks were immersed for 5min in 17% EDTA and washed with distilled water for 5min, then samples were sterilized for 30min at 120°C. The dentin samples were inoculated with 0.1mL of E. faecalis suspension in 5mL BHI (Brain Heart Infusion) and incubated at 37°C for 5days. After contamination, the specimens were distributed into ten groups (n=10) according to surface treatment: GI - 5mL NaOCl 2.5%, GII - 5mL NaOCl 2.5%+808nm diode (0.1W for 20s), GIII - 5mL NaOCl 2.5%+970nm diode (0.5W for 4s), GIV - 808nm diode (0.1W for 20s), GV - 970nm diode (0.5W for 4s), GVI - CHX 2%, GVII - CHX 2%+808nm diode (0.1W for 20s), GVIII - CHX 2%+970nm diode (0.5W for 4s), GIX - positive control and GX - negative control. Bacterial growth was analyzed by turbidity and optical density of the growth medium by spectrophotometry (nm). Then, the specimens were processed for analysis ultrastructural changes of the dentin surface by SEM. The data was subject to the One-way ANOVA test. GI (77.5±12.1), GII (72.5±12.2), GIII (68.7±8.7), GV (68.3±8.7), GVI (62.0±5.5) and GVII (67.5±3.3) were statistically similar and statistically different from GIV (58.8±25.0), GVIII (59.2±4.0) and control groups (p<0.05). SEM analysis showed a modified amorphous organic matrix layer with melted intertubular dentin when dentin samples were irradiated with 970nm diode laser; erosion of the intertubular dentin in blocks submitted to 808nm diode laser irradiation; and an increased erosion of the intertubular dentin when 2.5% NaOCl was associated to the different wavelengths lasers. All the therapeutic protocols were able to reduce the bacterial contingent in dentin blocks, and the association of diode laser and solutions did not significantly improve the reduction of the bacterial contingent.

Efficacy of Different Irrigation Protocols for Removing Gutta-Percha and Sealer Remnants in Artificial Un-instrumented Areas.

Objective:The purpose of this study was to determine the efficacy of different irrigants and irrigation protocols in the removal of gutta-percha and sealer from simulated un-instrumented areas.Methods:Eighty-four uniradicular teeth were used. After standardizing working length (WL) and preparing the glide path, coronal flaring was performed. The instrumentation phase was completed with ProFile rotary instruments up to size #35 LightSpeed LSX. Roots were split into halves: in one of them, a groove was prepared in the apical 6 mm. In the opposite one, 5 depressions were made (at 2, 4, 6, 8 and 10 mm). Irregularities were filled with AH Plus sealer and flowable gutta-percha. The Efficacy of sodium hypochlorite (NaOCl) and chloroform in removal of material and the effect of positive pressure (PP), passive ultrasonic irrigation (PUI) (one or three cycles) and paper points were analysed with the chi-square test.Results:Delivery by PP did not eliminate the obturator material from any artificial depression. Chloroform, when activated, demonstrated a significant linear trend in the amount of gutta-percha removed at all tested levels (P<0.01). The use of paper points after passive delivery of chloroform increased significantly the removal of gutta-percha in the groove and at 4 and 10 mm (P<0.05). Three cycles of PUI and chloroform showed significantly fewer remnants of gutta-percha (P<0.01).Conclusion:Positive pressure was not effective in the removal of obturator materials with any of the tested irrigants. Chloroform delivered by PP in combination with paper points obtained a better cleaning efficacy, although its activation using PUI for three cycles of 20 s showed the best cleanliness.

Degree of conversion of a self-adhesive endodontic sealer when used as bulk material.

This study tested the null hypothesis that the opacity of RealSeal SE (RSSE) sealer makes light-curing inefficient, while the degree of conversion (DC) is similar regardless of curing method. Fourteen uniradicular teeth were sectioned at 15 mm from the apex. Root canals were instrumented using the Reciproc file system, bulk-filled with RSSE, and divided randomly into two groups (dual-cure or self-cure). DC was determined by micro-Raman spectroscopy at 24 h, 48 h, and 1 week after filling, at 6, 9, and 12 mm from the coronal end. Contrast ratio (Yb/Yw) was used to determine the opacity of the material. Descriptive statistics and nonparametric tests were used, and significance was defined as a P value of less than 0.05. Opacity was almost total by the first section, at 6 mm. In dual-cure mode, DC values at 24 h were lower in the apical section (63.8%) than in the more coronal sections and were lower than in self-cured specimens (87.4%). Light-curing of the coronal end did not improve DC. These differences remained at 48 h and 1 week. Only a small (2%) but significant increase in DC was observed in evaluations at 24 h and 1 week. (J Oral Sci 58, 333-338, 2016).

The Effect of Foraminal Enlargement of Necrotic Teeth with the Reciproc System on Postoperative Pain: A Prospective and Randomized Clinical Trial

IntroductionThe aim of this prospective study was to evaluate the postoperative pain that followed root canal treatments performed with a single-file reciprocating system on asymptomatic uniradicular necrotic teeth with and without foraminal enlargements (FEs). MethodsForty-six volunteers were randomly divided into 2 groups according to the established working lengths. The FE group had a working length of 0.0 mm from the apex, and the control group had a working length of 1.0 mm short of the apex. The treatments of both groups were performed with a Reciproc R40 (VDW, Munich, Germany) instrument. Both groups underwent the same treatment protocol with the exception of the established working length. The volunteers were instructed to record their pain (none, mild, moderate, or severe) on a visual analog scale at 24 hours, 72 hours, and 1 week after the procedures. The Kruskal-Wallis test was used to identify significant differences. ResultsOverall, 82.22% of the patients indicated no pain or mild pain. A greater proportion of the patients in the FE group reported mild pain compared with patients in the control group in the first 24 hours (P < .05). At 72 hours and 1 week, there were no statistically significant differences between the groups (P > .05). ConclusionsFEs during endodontic treatments of asymptomatic necrotic, uniradicular teeth that were performed in single visits using the Reciproc R40 reciprocating file resulted in a low incidence of pain. After 24 hours, the FEs resulted in more patients reporting mild pain compared with the control group, but no differences were observed at 72 hours or 1 week.

Evaluation of the pattern dimensions of cast-metal posts in uniradicular teeth

Introduction Accurate dimensions of cast-metal posts are relevant to the survival of dental prostheses. Objective The aim of this study was to verify if the dimensions of cast-metal posts accord with ideal clinical criteria. Material and method For the evaluation, 285 periapical radiographs, from a total of 80 teeth, were taken from the charts of patients that attended the clinics at the Dental School of the Federal University of Goiás, from March 2008 to October 2012. Only periapical radiographs of single-rooted teeth with post and core were included in the study. The radiographic evaluation was conducted with the assistance of a magnifying glass and a view box, in a room with low luminosity. The dimensions of the post and core were established with the help of a digital caliper, and the following measurements were considered: a) LR (Length Remnant); b) LP (Length Post); c) BS (Bone Support); d) DR (Diameter Root); e) DP (mesiodistal diameter post). The post and core were classified as acceptable or deficient by reference values with a margin of error of 0.2 mm. For descriptive analysis, the data were cataloged using SPSS software (version 17.0). Result With regard to the length of the post and core, only 26.25% and 43.75% of the post and core were classified as acceptable according to the two-thirds rule and fulcrum dental rule, respectively. With regard to the mesiodistal diameter of the post and core, 55% were classified as acceptable. Conclusion Within the limits of this study, it can be concluded that the cast-metal posts evaluated do not accord with the ideal clinical criteria.

Influence of the artefact reduction algorithm of Picasso Trio CBCT system on the diagnosis of vertical root fractures in teeth with metal posts.

To assess the influence of the artefact reduction algorithm (AR) available on the Picasso Trio 3D(®) imaging system (Vatech, Hwaseong, Republic of Korea) on image quality [greyscale values, contrast-to-noise ratio (CNR) and artefact formation] and diagnosis of vertical root fractures (VRFs) in the teeth with intracanal metal posts. 30 uniradicular teeth had their crowns removed and their roots endodontically treated to receive intracanal metal posts. In 20 teeth, both complete (n = 10) and incomplete (n = 10) VRFs were created. Each tooth was scanned twice, with and without AR activation. The mean and variation of greyscale values, as well as CNR, were calculated for all images. Subsequently, an evaluator compared the amount of artefact (cupping, white streaks and dark bands) in all images. Five evaluators rated for VRF presence using a five-point scale. Mean greyscale values and CNR were significantly decreased in images acquired with the AR. The usage of the algorithm promoted an overall reduction of image artefacts. Regarding the diagnosis of complete and incomplete VRFs, the use of the AR had an overall negative impact on specificity and accuracy. While indeed reducing artefact formation, the use of the AR, instead of improving the impact on the diagnosis of VRFs in teeth with intracanal metal posts, had a negative impact on the diagnosis.

Prognostic factors on periapical surgery: A systematic review.

BackgroundAnalyze the most important prognostic factors when performing periapical surgery and compare the success rates of distinct authors.IntroductionPeriapical surgery is an approach to treat non-healing periapical lesions and it should be viewed as an extension of endodontic treatment and not as a separate entity.Material and MethodsA search of articles published in Cochrane, PubMed (MEDLINE) and Scopus was conducted with the key words “prognostic factors”, “prognosis”, “periapical surgery”, “endodontic surgery” and “surgical endodontic treatment”. The inclusion criteria were articles including at least 10 patients, published in English, for the last 10 years. The exclusion criteria were nonhuman studies and case reports.Results33 articles were selected from 321 initially found. Ten articles from 33 were excluded and finally the systematic review included 23 articles: 1 metaanalysis, 1 systematic review, 2 randomized clinical trials, 6 reviews, 12 prospective studies and 1 retrospective study. They were stratified according to their level of scientific evidence using the SORT criteria.ConclusionsFactors associated with a better outcome of periapical surgery are patients ≤45 years old, upper anterior or premolar teeth, ≤10 sized lesions, non cystic lesions, absence of preoperative signs and symptoms, lesions without periodontal involvement, teeth with an adequate root-filling length, MTA as root-end filling material, uniradicular teeth, absence of perforating lesions, apical resection < 3 mm, teeth not associated to an oroantral fistula and teeth with only one periapical surgery. Key words:Prognostic factors, prognosis, periapical surgery, endodontic surgery and surgical endodontic treatment.