Evaluation of various obturation techniques with bioceramic sealers in 3D-printed C-shaped canals.

This in vitro study compared various obturation techniques with bioceramic sealers for filling C-shaped 3D-printed replicas. A mandibular molar with a C-shaped root canal with a C1 configuration was obtained. After instrumenting with M3 Pro Gold files (United Dental, Shanghai, China) up to size #30/0.04, a CBCT scan of the tooth was taken. Sixty 3D-printed replicas of the tooth were created. The samples were obturated with EndoSeal TCS sealer (E. TCS; Maruchi, Wonju, Korea) or EndoSeal MTA (E. MTA; Maruchi, Wonju, Korea) (n = 30). The samples in each group were obturated with the following techniques (n = 10): (1) single-cone technique (SC), (2) SC with ultrasonic activation (UA), and (3) cold hydraulic compaction (CHC). Following incubation, the replicas' apical, middle, and coronal thirds were inspected under a digital microscope, and the proportion of filling material and void were calculated. Also, the obturation time and sealer extrusion were recorded. Data were analyzed using ANOVA, LSD post-hoc, and the chi-square tests (α = 0.05). The results indicated that in the apical third, E. TCS-SC, E. TCS-UA, and E. MTA-UA had the lowest void percentage among groups (p < 0.05). In the middle thirds, samples obturated with E. TCS-UA showed a significantly lower void percentage among all groups (p < 0.05). However, in the coronal third, E. TCS-CHC showed the least void percentage (p < 0.05), followed by E. TCS-UA and E. MTA-CHC. The E. TCS-SC and E. TCS-UA were the least time-consuming methods (p < 0.05). Sealer extrusion significantly differed among the groups, with E. MTA-UA and E. TCS-UA showing higher incidence (p = 0.019). It was concluded that E. TCS-UA was the most convenient obturation technique. However, care must be taken when obturating the canals with high flow and ultrasonic activation near the vital anatomical landmarks.

The Efficacy of Different Antibiotic Compounds in Regenerative Treatment of Immature Necrotic Teeth.

Objectives: Endodontic treatment of immature teeth poses a significant challenge, especially in achieving a proper seal using traditional obturation methods. Revascularization presents itself as an alternative approach to this problem, and the application of triple antibiotic paste (TAP) has been suggested as a means to achieve disinfection during the procedure. This study aims to compare the antibacterial properties of three different antibiotic combinations to assess their effectiveness on root canal disinfection. Materials and Methods: Eighty samples were employed to assess the impact of three antibiotic combinations on Enterococcus faecalis, Escherichia coli, Streptococcus mutans, and a combination thereof. The antibiotics included metronidazole, ciprofloxacin, and cefaclor (CCM), the commonly used TAP, and a double antibiotic paste (DAP) composed of metronidazole and ciprofloxacin. Dentin shavings collected using Gates-Glidden drills were placed in microtubes containing a 2ml standard bacterial suspension. Microtube contents were diluted and cultured on BHI agar plates, with colony counts calculated based on dentine shavings' weight in CFU/mg. Kruskal-Wallis and Dunn's post-hoc tests were used for statistical analysis and P<0.05 was considered significant. Results: A significant difference in mean CFU was observed among all bacterial groups (P<0.05). Dunn's post-hoc analysis showed a significant difference only between the control group (methylcellulose) and the other antibiotic groups. There was no significant difference between the other antibiotic groups in two-by-two comparisons. Conclusion: There was no significant difference in the antimicrobial properties of DAP, TAP and CCM. Therefore, DAP and CCM may be used during regenerative treatment.

Negotiability of mesiobuccal canals in maxillary first molars using different path file systems.

Background: In endodontics, glide path creation has been extensively considered a mandatory clinical step to improve the safety and efficiency of rotary nickel-titanium instruments. The high anatomic variations in the mesiobuccal (MB) root of the maxillary molars are observed in the form of canal configuration, number, and position.The aim of this study was to evaluate the negotiability of MB canals in maxillary molars using different pathfiling systems (ProGlider, R-pilot, HyFlex electrical discharge machining [EDM], WaveOne Gold Glider, and C-Pilot). Materials and Methods: This in vitro study included 125 maxillary first molars with closed apex. Before preparation, all teeth were scanned by periapical radiograph for review of the presence of second MB (MB2) canals, without any resorption or calcification, and moderate curve of MB root canal. Subsequently, the access cavity was prepared with a Diamond Fissure Bur. Then, the samples were divided into five groups (ProGlider, R-pilot, HyFlex EDM, WaveOne Gold Glider, and C-Pilot). Certain relevant indices were recorded for analysis, such as the negotiability of the glide path file in the MB canals, file fracture rate, and negotiation speed. The level of significance P value was set at 0.05. Results: In this study, HyFlex EDM was the only path file that could not reach the full working length (WL) in some cases. The highest frequency of file fracture in the MB2 was observed with HyFlex EDM (24%); nevertheless, R-Pilot presented an intermediate fracture rate (16%), and both ProGlider and WaveOne Gold Glider were the safest files (4%) in this regard. However, there were no significant differences between the groups (P = 0.065). The lowest and the highest average time of reaching full WL was observed with WaveOne Gold Glider and HyFlex EDM; nonetheless, there was no significant difference between the four rotary groups. The average number of pecks in HyFlex EDM was significantly higher in comparison to those reported for WaveOne Gold Glider and ProGlider. Conclusion: Path files used for glide path preparation in the MB2 canals of maxillary molars should be flexible with low taper. The use of HyFlex EDM in the MB2 canals is not recommended due to its high taper.

Investigation of the effect of hydrochloric acid with different concentrations on mineral trioxide aggregate plug and dentin.

Background: Mineral trioxide aggregate (MTA) becomes a hard mass after setting and making it difficult to remove and can cause significant problems in the retreatment process. The aim of this study was to evaluate the effect of different concentrations of hydrochloric acid (HCl) on MTA dissolution and its effect on dentin. Materials and Methods: In this in vitro study, 45 single-root premolars were selected. Artificially open apex was created in all samples with similar process. The samples were randomly divided into 4 experimental groups of 10, and a control group of 5. Four-millimeter thick apical plugs of Root MTA were placed in all samples in an orthograde manner. HCl was used at concentrations of 3.75%, 7.5%, 15%, and 22.5% (w/v) for the experimental groups and normal saline for the control group. Each sample was exposed to the desired solution for 15 min. Then, MTA retrieval and reaching the working length were attempted with k-file # 30. The times of each sample were recorded. Furthermore, after longitudinal incision of the roots with a disc, the dentin surfaces of canals were examined with a Dino-Lite microscope (×50). Results were analyzed by Shapiro-Wilk test and one-way analysis of variance tests. The level of significance P value was set at 0.05. Results: The lowest average time of reaching working length was observed with group 22.5% that was significantly lower than 15% and 7.5% concentrations (P = 0.005 and P = 0.011). Furthermore, by examining with ×50 of Dino-Lite microscope, no difference was observed on the canal walls. Conclusion: The optimum concentration of HCl was 7.5%. Furthermore, different concentrations of HCl had no significantly different effect on the dentinal canal wall using Dino-Lite microscope with ×50.

Comparative Analysis of Stress Distribution through Finite-Element Models of 3 NiTi Endodontic Instruments while Operating in Different Canal Types.

Statement of the Problem: Distribution of stress along endodontic instruments determines their fracture resistance during instrumentation of root canals. The cross-sectional design of instruments and root canal anatomy are of the most important factors affecting the stress distribution. Purpose: The purpose of this study was to evaluate the stress distribution in different cross-sectional design of nickel-titanium (NiTi) endodontic instruments operating in different canal anatomies using finite element analysis (FEA). Materials and Method: In this original finite element analysis study, 3-dimensional models of convex triangle (CT), S-type (S), and triple-helix (TH) cross-sectional designs with the size of 25/04 simulated rotational movements through 45ᵒ and 60ᵒ angled root canals with 2- and 5-mm radii using ABAQUS software. The stress distribution was evaluated by the means of FEA. Results: CT showed the lowest stress values followed by the TH and S ones. The most stress concentration was detected in the CT apical third while, TH revealed better stress distribution all along its length. 45ᵒ curvature angle and 5-mm radius applied the lowest stress to the instruments. Conclusion: Higher value of radius and smaller curvature angle apply lower stress values to the instrument. CT design shows the lowest stress level with the most stress concentration in its apical third while the triple-helix design has a better stress distribution. Thus, it is safer to use convex triangular cross-section mostly for coronal and middle thirds in initial steps of shaping and triple-helix for the apical third in final steps.

Post-treatment Flare-up Incidence after Using Nano Zinc Oxide Eugenol Sealer in Mandibular First Molars with Irreversible Pulpitis.

STATEMENT OF THE PROBLEM: Some patients may report moderate-to-severe pain and/or swelling following root canal treatment, which is undesirable for both the patient and dentist and may require an unscheduled emergency visit by patients to relieve their symptoms. PURPOSE: The aim of this study was to evaluate the post-treatment flare-up incidence following application of nano zinc oxide-eugenol (NZOE) sealer in mandibular first molars with irreversible pulpitis. MATERIALS AND METHOD: This single-blinded study was performed on 60 patients having mandibular first molars with irreversible pulpitis. After signing the written consent form, the patients were randomly divided into two groups considering their age range (20-34 and 35-50 years). Individuals without systemic diseases and with a first mandibular molar diagnosed with irreversible pulpitis due to caries, no sinus track and abscess, normal periapical radiographic appearance, no spontaneous pre-treatment pain, not taken any medication for at least 8 hours before the treatment visit were included in this study. Patients of both sexes with age range of 20 to 50 years were selected. In order to obturate the root canal space, AH26 sealer was used in the one group and the synthesized NZOE was applied in another group. The patients were then given questionnaires to report the severity of pain and presence of swelling during 6, 18, 24, and 48 hours of follow-up. The data was analyzed using SPSS v.19 software applying repeated measures ANOVA. The significance level was set at 0.05. RESULTS: The severity of pain was significantly lower in NZOE group at 24 hours post-treatment (p= 0.003). Patients reported no symptoms of swelling in any group. CONCLUSION: NZOE sealer manifested satisfactory results and could be regarded as a promising substitute to routine sealers since patients may experience less pain during the first hours after receiving root canal therapy.

Intratubular Enterococcus faecalis viability assessment following root canal instrumentation with rotary and reciprocating systems via fluorescence microscopy.

Background. The present in vitro study aimed to compare the effectiveness of the WaveOne and ProTaper Gold systems in removing the Enterococcus faecalis biofilm. Methods. Thirty-eight mandibular premolars were selected. The root canals were assigned to standard control (canals serially enlarged with ProTaper Gold S1-S2-F1-F2, n=15) and experimental (canals enlarged with Primary WaveOne file, n=15) groups. Following the instrumentation procedure, the root canals underwent a sampling procedure, and the colonyforming unit (CFU) counts were determined. The samples were also evaluated under a fluorescent microscope to evaluate viable bacteria. The data were analyzed using independent samples t test and paired samples t test. Results. The results showed that, compared with the ProTaper group, the WaveOne group exhibited the least viable bacteria (P =0.004). Conclusion. It was concluded that comparison with the ProTaper Gold rotary system, the WaveOne reciprocating file is more successful in reducing intratubular viable bacteria counts.

Endodontic Treatment of a Mandibular Second Premolar with Type XVII Sert and Bayirli's Canal Anatomy.

For a successful root canal treatment, it is critical for the clinician to have a complete knowledge of the root canal morphology, interprets radiographs critically and properly assesses the pulp chamber floor. Anatomical variations are critical in diagnosis and a successful treatment outcome in endodontics. Knowledge of root canal morphology and anomalies is essential to succeed in root canal therapy. Mandibular premolars are famous for their atypical morphology. But the occurrence of type XVII Sert and Bayirli's root canal type is very rare in them. The purpose of this case report is to present treatment of a seldom root canal system in a mandibular second premolar. Reports of unusual cases cause clinicians to do an accurate clinical examination and radiographic interpretation and consider atypical root canal configurations.

Influence of Two Preparation Techniques on Transportation of Simulated Type II Root Canals.

INTRODUCTION: The purpose of this study was to evaluate the changes of canal configuration in simulated type II root canals that were instrumented by two different techniques using ProTaper Universal rotary files. METHODS AND MATERIALS: Sixty simulated type II root canal in resin blocks were made and randomly divided into two groups. Pre and post-instrumentation images of resin blocks were prepared using stereomicroscope from three surfaces of blocks included two longitudinal section (mesiodistally and buccolingually), and one cross sectional surface. In the first group (G1) the straight canal was instrumented to the working length and the other canal was instrumented up to the area of canals junction. In second group (G2) both canals were instrumented to working length. The superimposed pre and post instrumentation images were assessed by the Adobe Photoshop software. The degree of transportation, centering ability, perimeter, surface and aspetic ratio (AR) in cross section and longitudinal section at apex, 3 mm and 5 mm above the apex, were measured. SPSS software, t-test and Mann-Whitney test were used for statistics analysis. RESULT: In mesiodistal direction, canal transportation was more (P=0.024) only in junction point in G2 which both canals were instrumented to working length. Also, surface changes were more significant (P=0.02) in G2 in cross sectional direction. The other parameter and also apical transportation had not significant difference in two groups. CONCLUSION: According to the results of this study, it can be concluded that both two preparation methods of type II canals can be used by rotary instruments.

Evaluation of the expression of VIII factor and VEGF in the regeneration of non-vital teeth in dogs using propolis.

OBJECTIVES: The purpose of the present study was the immunohistochemical evaluation of VEGF and VII factors in dog's teeth pulp revascularized with MTA and propolis. MATERIALS AND METHODS: 144 mature and immature two rooted dog's premolar canals were selected. Pulp necrosis and infection were established after 2 weeks and the disinfection of the canals was done with copious NaOCl irrigation and triantibiotic mixture (ciprofloxacin, metronidazole, and minocycline) for 3 weeks. Subsequently, the blood clot was evoked in the canal by periapical tissue irritation with a k-file. The samples were randomly divided into 6 experimental groups: propolis (groups 1, 2), MTA (groups 3, 4), and parafilm (groups 5, 6) in immature and mature teeth. The animals were sacrificed and samples were prepared for immunohistochemical evaluation of VEGF and the VIII factor. RESULTS: Tissue regeneration was seen in 64.5% of MTA, 38% of propolis, and 0% of parafilm group samples. Expression of VEGF and VIII factor in the propolis group was more than the MTA group and it showed a reduction after 3 months in comparison to 1 month. VEGF and VIII factor were seen in stromal cells in addition to endothelial vessel cells. Overall, expression of angiogenic factors was more in the open apex teeth compared to close apex ones. CONCLUSION: According to the results of this study, propolis can induce the expression of VEGF and VIII factor in infected mature and immature dog's teeth and is a suitable biomaterial for the revascularization technique.

Tooth Discoloration Resulting from a Nano Zinc Oxide-Eugenol Sealer.

INTRODUCTION: A desirable quality of any endodontic sealer is its ability to be tooth color friendly. Therefore the aim of the present study was to evaluate the tooth discoloration potential of a nano zinc oxide-eugenol (NZOE) sealer. METHODS AND MATERIALS: In order to evaluate tooth discoloration, the pulp chamber of 60 human maxillary central and lateral incisors were filled with one of the sealers, naming AH-26 (resin-based sealer), Pulpdent sealer (ZOE-based) and a NZOE experimental sealer. Color measurements was assessed at the baseline (before placement of sealers) (T0), 24 h (T1) and 72 h (T2) h, 1-week (T3), and 1-month (T4) after the placement of sealers using the Easy Shade spectrophotometer. Data were analyzed in SPSS software using one-way ANOVA, and repeated measured ANOVA. RESULTS: No significant differences were observed when the paired comparison test was performed (P>0.05). CONCLUSION: The tested NZOE sealer had similar tooth discoloration potential in comparison with AH-26 and ZOE sealer.

Cutaneous Sinus Tract from Mandibular Second Molar with C-shaped Canal System and Improper Former Root Canal Treatment: A Case Report.

Here, we report the diagnosis and treatment of an extraoral cutaneous sinus tract originating in a mandibular second molar with a C-shaped root canal system. The patient was referred to our department by a dermatologist after a series of unsuccessful treatments, including antibiotics. Diffuse radiolucency on a preoperative radiograph revealed that earlier root canal treatment had been only partially successful. Consequently, we performed retreatment of the root canal comprising removal of the former restoration and gutta-percha, cleaning and shaping, and passive irrigation with sodium hypochlorite. The patient responded well, and the cutaneous lesion completely resolved uneventfully within 1 month postoperatively. Preoperative recognition and thorough knowledge of the root canal anatomy and conventional methods of obturation are necessary in performing successful endodontic treatment.

Tissue Reaction to Different Types of Calcium Hydroxide Paste in Rat.

The purpose of this study was to compare the biocompatibility of two types of calcium hydroxide paste in subcutaneous tissue in rat. Twenty-two Wistar rats were divided into 4 experimental (n=5 each) and one control (n=2) group. A polyethylene tube filled with either Dentsply or Sure-Paste was implanted in each rat in the experimental groups, while an empty polyethylene tube was used in the control group. After 15 or 60 days, the animals were sacrificed and histopathological examination carried out. Tissue reaction was assessed by inflammatory cell infiltration using a 4-point scoring system, ranging from 0 to 3. Data were analyzed with the Kruskal-Wallis, Wilcoxon, and McNemar tests. Both types of paste induced an inflammatory response at each time point, although the intensity varied. A significant reduction in the number of inflammatory cells was observed at 60 days. Dentsply appeared to induce a more marked inflammatory response at both time points, although the difference was not significant. These results suggest that both types of paste are biocompatible with subcutaneous tissue in rat.

Management of Traumatized Permanent Incisors. Revascularization and Delayed Replantation.

This article reports a clinical case of a 9-year-old boy with a traumatic injury to the maxillary central incisors 24 hours after a fall in his schoolyard. The upper left central incisor was avulsed and was kept in saliva for four hours from the moment of trauma until its replantation. The right one was necrotized after one month. We describe successful revascularization treatment of right necrotic immature upper incisor and delayed replantation of left one. After 18 months, radiolucent lesions in the periapical areas of both maxillary central incisors had healed, and root apex development was noted with thickening of the walls in tooth #8.

In vitro evaluation of tooth discolouration induced by mineral trioxide aggregate Fillapex and iRoot SP endodontic sealers.

The purpose of this study was to evaluate the tooth discolouration potential of two new calcium-silicate-based sealers (mineral trioxide aggregate (MTA) Fillapex and iRoot SP). Sixty premolars were resected below the coronal third of the root. Pulp chamber was instrumented and irrigated via the apical access. Samples were randomly assigned into groups A (MTA Fillapex), B (AH plus), C (iRoot SP) and D (unfilled as control). Colour assessment was performed at baseline, 1st, 3rd and 6th months with an intraoral spectrophotometer. Analysis of variance with additional multiple comparisons of post hoc were used for statistical analysis. All sealers caused perceptible tooth discolouration and there was no statistically significant difference between them. Discolouration progressed within the first 3 months and then decreased until the 6th month.

Effect of Molding Technique on Iwo Physical Properties of Acrylic Resin Specimens.

The aim of this study was to compare dimensional changes and flexural strength of specimens processed by conventional and injection-molding techniques. SR-Ivocap Triplex Hot Resin was used for conventional pressure-packed, and SR-Ivocap High Impact was used for injection-molding techniques. Measurements were recorded at 24-hour, 48-hour and 12-day intervals. Three-point test and statistical analysis were carried out. After each water storage period, the acrylic specimens produced by injection method exhibited less dimensional change compared to those produced by the conventional technique. Within the limitation of this study, dimensional changes and flexural strength of acrylic resin specimens were influenced by molding technique, and the SR-Ivocap injection procedure exhibited higher dimensional accuracy and flexural strength compared to conventional molding.

The Effect of Low Level Laser Therapy on Direct Pulp Capping in Dogs.

Introduction: The aim of this study was to determine the histologic effect of low level laser therapy (LLLT) with or without the use of mineral trioxide aggregate (MTA) on exposed pulp tissues of dogs. Methods: Twenty-five premolar teeth in three healthy mature dogs were randomly divided into five groups. In group 1, the pulp tissue was capped with MTA. In groups 2 and 3, before capping with MTA, the exposure site was irradiated by low power lasers at 630 nm (20 mW, 150 seconds, 7.5 J/cm2) and 810 nm (peak power 80 W, average power 50 mW, 1500 Hz, 50 seconds, 6.25 J/cm2) wavelengths, respectively. In groups 4 and 5, the exposure site was irradiated similar to that described in groups 2 and 3, but the pulp tissue was covered by gold foil instead of MTA. After 2 months, the animals were sacrificed and the samples were prepared for histologic evaluation. Results: There were differences in pulpal response and dentinal barrier formation among the study groups. The morphology of pulpal tissue and the integrity of dentinal barrier and formation of odontoblastic layer were more favorable in the first three groups. The occurrence of extensive and intense inflammation and necrosis was more frequent in groups 4 and 5. Conclusion: Under the conditions used in this study, the presence of MTA as a pulp capping material was more important than laser therapy in the success of direct pulp capping (DPC) treatment. MTA proved to be an effective material either alone or in combination with laser irradiation in vital pulp therapy.

Cytotoxicity of a New Nano Zinc-Oxide Eugenol Sealer on Murine Fibroblasts.

INTRODUCTION: The aim of this study was to evaluate the cytotoxicity of a new nano zinc-oxide eugenol (NZOE) sealer in comparison with AH-26 and Pulpdent root canal sealers. METHODS AND MATERIALS: The L929 mouse fibroblast cells were cultivated and incubated for 24, 48 or 72 h with different dilutions (1/1, 1/2, 1/4, 1/8, 1/16 and 1/32) of culture media previously exposed to either of the test sealers naming NZOE, AH-26 or Pulpdent. At the end of incubation period, the effect of sealers on cell viability was evaluated using Mosmann's Tetrazolium Toxicity (MTT) colorimetric assay. The data was compared using the one-way analysis of variance (ANOVA) followed by the Tukey's post hoc test for multiple comparisons. RESULTS: After 24, 48 or 72 h, both NZOE and Pulpdent sealers inhibited cell viability at 1/1, 1/2 and 1/8 dilutions. Within the 24 and 48 h, the AH-26 sealer reduced the cell viability at all dilutions except the 1/32 solution; however after 72 h even the 1/32 dilution was cytotoxic. CONCLUSION: The biocompatibility of the nano zinc-oxide eugenol sealer was comparable to Pulpdent sealer and lower than AH-26.

A Survey over the Dentists' and Endodntists' Approaches towards the Management of Endodontic Emergencies in Mashhad, Iran.

INTRODUCTION: Pain or swelling caused by various stages of inflammation/infection of the pulp/periradicular area is among endodontic emergencies. Determining the most effective method of emergency treatment is a challenging issue in endodontics. The goal of this study was to determine and compare the level of knowledge in general dentists and endodontists about endodontic emergency treatment plan in Mashhad, Iran in 2012-2013. METHODS AND MATERIALS: In this cross-sectional descriptive study, 152 questionnaires were distributed among 120 general dentists and 32 endodontists of Mashhad. The questionnaire contained two separate parts. The first part included demographic information and in the second part different treatment protocols were suggested for 12 various conditions of pulp/periapical emergencies, and the participants were asked to choose the correct option(s). To determine the relationship between qualitative variables, the chi-square analysis was used. The level of significance was set at 0.05. RESULTS: There were significant differences between treatment plans presented by general dentists and endodontists about endodontic emergencies, especially in cases of necrotic pulp and subsequent swelling. CONCLUSION: Level of knowledge of dentists about the indications of incision and drainage, intra-canal medicament, root filing beyond the apical foramen and antibiotic prescription was not enough. These findings highlight the importance of refreshing courses for general dentists to improve their competency in the management of endodontic emergencies.

Metacognition and Body Image in Predicting Alexithymia in Substance Abusers.

BACKGROUND: Substance dependency is one of the biggest problems and worries of the world. It stunts the growth of society and causes various problems such as reduction in public health, increase in mortality, rise in social and domestic traumas, loss of educational and occupational opportunities, involvement with the judicial system, and development of the substance-abuse cycle. OBJECTIVES: The aim of this study was to determine the role of metacognition and body image in predicting alexithymia in substance abusers. PATIENTS AND METHODS: The research sample included addicts (males and females aged 10 to 70 years) who referred to the addiction treatment and counseling centers of three Iranian cities of Zahedan, Sari, and Neyriz. Participants were selected by random sampling. The metacognitive strategy questionnaire (MCQ-30), physical self-description questionnaire (PSDQ), and Toronto alexithymia scale (TAS-20) were used for data collection. The hypotheses were tested using the Pearson's correlation method and regression analysis. RESULTS: According to the results of the current study, the highest correlation was between alexithymia and the cognitive awareness subscale (r = 0.305; P < 0.01).There was no significant correlation between alexithymia and body image. Based on the multiple regression analysis, the three predictors explained 11% of the variance (R(2) = 0. 11, F = 3.981; P < 0.01). Cognitive awareness significantly predicted 9% of the variance (ß = 0.305; P < 0.01), and the other subscales predicted about 2%. CONCLUSIONS: These findings demonstrated that metacognition had an important role in predicting alexithymia in the substance abusers, which underscores the necessity of precautionary measures.