Showing 31 results for Post
M. Atai, M. Ghavam, E. Yasini, M. Mirzaei, A. Pahlavan, M. Hasani Tabatabaie, S. Arami, H. Kermanshah, S. Kameli,
Volume 21, Issue 2 (11-2008)
Abstract
Background and Aim: Nonmetallic tooth- colored posts adhere to canal walls by dentin bonding agents and resin cements. Better retention and proper distribution of stress result from enough and proper bonding. The purpose of this study was to evaluate bond strength of D.T. Light - post with two different resin cements (self-cure & dual-cure) and to investigate the effect of irrigating solutions applied in root canal on bond strength of the resin cements and D.T.Light- post to root canal wall.
Materials and Methods: In this experimental study 40 single root teeth (maxillary canine & central) were selected and stored in 0.1% thymol solution for one week and transferred to distilled water. The teeth were decoronated 2mm above CEJ. The canal space was mechanically enlarged using k-files (up to # 70). The teeth were randomly divided into two groups. The first group was irrigated with 2.6% NaOCl, and the second was irrigated with normal saline. After drying, the teeth were filled with gutta percha cones using lateral condensing method. After two weeks the post space was prepared and D.T.Light- post was inserted in each subgroup using self or dual-cure cements according to manufacturer's instructions. After thermocycling, the apical part was cut 1cm below CEJ. The remained length was divided into 9 equal sequential sections. Each section was submitted to shear push-out test in universal testing machine. Statistical analysis of the bond strength data was performed using ANOVA and post hoc tests with p<0.05 as the level of significance. All failed specimens were examined under stereomicroscope. Degrees of conversion of the cements were determined by FTIR.
Results: Significant difference in bond strength values were found among sites (P=0.001) and cements (P=0.03). With increasing in depth, bond strength decreased. The mean bond strength value in dual-cure resin cement was higher than self-cure cement. The irrigating solutions caused no significant difference in bond strength (P=0.46). DC% had significant difference in various depths.
Conclusion: According to the results of this investigation, bond strength of dual-cure cement is higher than self-cure one in D.T Light- post because of post's translucency. 2.6% sodium hypochlorite does not affect the bond strength.
Sh. Nasermostofi, A. Raghanians, S. Banava, E. Jalalian, A. Abdollah,
Volume 22, Issue 1 (8-2009)
Abstract
Background and Aim: A key factor in restoring the endodontically treated teeth is ferrule preparation. When the ferrule is absent, occlusal loads may cause the post or root to fracture. The purpose of this in vitro study was to evaluate the effect of ferrule preparation on fatigue resistance of teeth restored with quartz-fiber posts.
Materials and Methods: Twenty single-rooted lower premolars having similar dimentions were randomly devided into two groups of 10. In control group the teeth were prepared with 3-mm of remaining coronal tooth structure and in test group teeth were prepared with 1-mm of remaining coronal tooth structure. The teeth were endodontically treated. 9-mm long Post holes were prepared, and D.T. light quartz-fiber(RTD,France) posts were cemented with Panavia F2(Kuraray,Japan).Then the core build up was done with Bisco core build up composite(Bisco,USA) and full metal crowns were cemented with Zinc phosphate(Harvard cement, Germany). All specimens were mounted in acrylic resin blocks and intermittently loaded (180 N) at an angulation of 45- degree to the long axis of the teeth at a frequency of 4 loads per second, until failure occurred.
Results: There was significant difference between the loads cycles of two groups studied. (p<0.0001).
Conclusion: The results of this study showed that an increased amount of coronal dentin significantly increases the fracture resistance of teeth restored with quartz-fiber posts.
S. Nokar, H. Dorriz, H. Hajimiragha, N. Shamashyan ,
Volume 22, Issue 1 (8-2009)
Abstract
Background and Aim: Debonding is the most common failure type of fiber posts. This in vitro study aimed to evaluate the bond strength of 3 different fiber posts cemented with a resin luting agent in three regions of prepared post spaces after being subjected to termocycling.
Materials and Methods Thirty six mandibular first premolars were sectioned at the cemento-enamel junction and were treated endodontically. After one week the post spaces were prepared and roots were divided into 3 groups of 12 specimens according to the post types (D.T.Composipost, D.T.White, D.T.Light). Sealbond Cement Dual II was used in all groups. One day after cementation, specimens were subjected to 3500 thermal cycles (5oC/55oC). Each root was then embedded in acrylic resin and sectioned perpendicular to long axis. Three 1-mm tick segments from apical, middle and cervical thirds were prepared. Push out test was performed. Data were analyzed with 2-way ANOVA (P<0.05). All root segments and dislodged posts were observed with stereomicroscope to figure out their failure modes.
Results: The post type had no significant effect on bond strength (p=0.08). However bond strength at the coronl segment was higher than the other segments (p=0.005). Mixed mode was the mostly occurred failure mode with D.T.Composipost and D.T.Light but with D.T.White, the mostly occurred failure mode was adhesive between the post and cement.
Conclusion: Different fiber posts have relatively similar bond strength to root dentin, bond strength at the coronl segment was higher than the other segments.
M. Saatchi, F. Mosavat, F Razmara, B. Soleymani,
Volume 22, Issue 4 (1-2010)
Abstract
Background and Aims: Despite the significant improvement in dentistry, pain after endodontic therapy is still of concern for patients. Non-steroidal anti-inflammatory drugs are the most commonly prescribed oral analgesics used for dental pain relief after root canal treatment. The purpose of this study was to compare the effectiveness of Ibuprofen versus slow-released Diclofenac Sodium in controlling pain following root canal treatment.
Materials and Methods: In this randomized clinical trial, mandibular molars with irreversible pulpitis in 90 patients were selected. The patients were divided into three groups (Ibuprofen, slow-released Diclofenac Sodium and placebo). After examination patients filled in the consent form. Then they received one of the mentioned drugs. After inferior alveolar nerve block, access cavity was prepared and the root canals were prepared using passive step back method. The canals were dried and temporary filling material was placed. Then the pain evaluation form (visual analog scale) was explained and delivered to the patients. Data were analyzed using Repeated Measurement ANOVA, Kruskal-wallis and Man-Whitney U tests.
Results: The mean pain intensity in slow-released Diclofenac Sodium group was 0.87 0.95, 1.17 1.10 for Ibuprofen group, and 2.14 1.70 for placebo group. The differences between groups were statistically significant (P<0.001). The effect of Ibuprofen in controlling post endodontic pain in the first 2 hours was more than slow-released Diclofenac Sodium (P=0.01), but in 10, 18, and 36 hours after treatment, slow-released Diclofenac Sodium was more effective than Ibuprofen (P<0.001).
Conclusion: Premedication with single dose of slow-released Diclofenac Sodium can control post endodontic pain for a longer period of time compared with Ibuprofen.
.
S. Yaghobee , V. Esmaeili ,
Volume 23, Issue 2 (10-2010)
Abstract
Background and Aims: Musculoskeletal disorders in dentists due to abnormal postures may result in economic and health problems. To prevent these problems, the working posture of dental students should be assessed and corrected in dental procedures. This study determine these problems and the effect of training courses on them by Rapid Entire Body Assessment method (REBA).
Materials and Methods: The posture of 69 students were assessed by REBA before and after of the “Ergonomic principles in dentistry” course. The subjects which were used in the training course were based on the previous studies on this issue. The REBA scores were assessed by SPSS software using Paired T-test.
Results: The results showed that the students’ posture should be corrected. Postures of 94.2% of students were in moderate and high risk level which needed to be corrected. The worst working positions were during surgery, endodontic and pediatric dentistry procedures. Although the REBA scores before and after training course were statistically different (P<0.05), the training did not improve the posture of students remarkably.
Conclusion: The students’ working postures should be improved. One-day ergonomic principles course improved the working posture of students but it was not sufficient. More training and instructions are needed to have a good working position in dental procedures.
Mohamad Hosein Lotfi Kamrani, Mahdi Tabrizizadeh, Yosef Khlil Sefat, Vahid Yegane,
Volume 24, Issue 4 (1-2012)
Abstract
Background and Aims: The seal provided by a root canal filling may be compromised by post space preparation. The aim of this study was to compare coronal microleakage around cast posts and prefabricated pins.
Materials and Methods: Thirty-eight extracted single-rooted, maxillary human teeth were prepared with step back method and filled with gutta-percha and sealer. After removing 8 mm of coronal gutta-percha with peeso-reamer drills #2 in twenty canals, the teeth were divided into three groups: cast post & core, prefabricated pin, and gutta-percha (without any post or pin). After thermocycling, the samples were immersed in India ink for seven days. Finally, the specimens were cleared and the coronal microleakage of dye was then measured by the stereomicroscope. The data were analyzed by One-way ANOVA and Tukey HSD tests.
Results: According to the results, the mean dye penetration in cast posts, pins, and group without post or pin was 3.3 (0.39), 5.2 (0.47), and 7.2 (0.15) mm, respectively. There was no statistically significant difference between the groups (P>0.05).
Conclusion: Considering the importance of adequate filling of crown for prevention of microleakage, the method for coronal filling must be selected with caution. According to the results of this study, no significant difference between microleakage of cast posts and prefabricated pins was observed.
Zafar Mahdavi Ezadi, Ezatolah Jalalian, Mohamad Hasan Salari, Shima Azimzad, Tahmine Safaie, Mahdi Shirazi, Behzad Salari,
Volume 26, Issue 4 (1-2014)
Abstract
Background and Aims : According to the common application of non-metal prefabricated posts in dentistry and lack of enough information about the stress distribution in the root canal walls by these posts, this study was performed to compare the effect of two simple taper and double taper posts on the stress distribution on root canal walls by photo elastic method .
Materials and Methods: The design of this study was experimental in photoelastic system. The posts, used in this investigation, were double taper and simple taper fiber posts with 0.9 mm diameter and 20 mm length and epoxy resin. First two photo elastic models with tooth dimensions were fabricated and the posts were placed inside the model. Then the core of the each post was fabricated on the model. Each models were loaded in polariscope and the formed fringe order colored ring were photographed.
Results: In 100 N, 90 degree angle loading in cervical and apical fringe order showed 2.50 and 1.39 in simple taper posts and 1.39 and 2.35 in double taper post. In 150 N, 30 degree angle loading in cervical and apical fringe order showed 4 and 2.65 in simple taper posts, and 4 and 2.5 in double taper post.
Conclusion: In the vertical and oblique loads, double taper fiber post showed better stress distribution than that of simple tapered posts.
Ezatollah Jalalian, Mona Sadegh, Rana Mohamadi, Reihane Aghajani, Elnaz Shafiee,
Volume 27, Issue 1 (4-2014)
Abstract
Background and Aims : The root fracture resistance of endodontically treated teeth depends on the types of posts. The aim of this study was to compare the effect of two types of bonded non-metallic posts with different elasticity modulus on the fracture resistance of endodontically treated teeth under compressive loads.
Materials and Methods: In this in vitro experimental study, 20 fresh extracted mandibular premolars were selected and sectioned adjacent to the CEJ and then were endodontically treated. The specimens were randomly divided into two groups (n=10). After post space preparations, the fiber RTD Light posts (R.T.D, France) and zirconia coated fiber posts (ICE light, Danville) were cemented into the root canals. Composite resin (Lumiglass R.T.D, France) cores were built up. Aluminium foil was used to mimic the PDL, and the specimens were embedded in acrylic resin and tested in a Universal Testing Machine. A compressive load was applied at a 90 degree angle until fracture at a crosshead speed of 1mm/min. Data were analyzed using one-way ANOVA and T test .
Results: The mean fracture resistance of R.T.D group was (1083.11 ± 156.74 (N)) and the mean of ICE light group was (865.18 ± 106.24 (N)). The highest mean fracture resistance was observed in RTD fiberglass and a statistically significant difference was observed between the two groups (P<0.001).
Conclusion: FRC posts with zirconia coating due to unfavorable fractures of the teeth should be used with caution, and thus, fiber posts are preferred.
Majid Akbari, Mohhamad Javad Moghaddas, Sara Majidinia,
Volume 27, Issue 2 (6-2014)
Abstract
Background and Aims: The aim of this study was to evaluate the fracture strength of restored teeth with three different types of E glass-fiber posts after thermo-mechanical loading.
Materials and Methods: Sixty extracted upper central incisor human teeth, with similar size, were selected and divided into three groups (n=20). Endodontic treatment was done in all groups and crowns were sectioned from 2 mm above CEJ. Then one type of posts in each group (Anthogyr, Svensk, Hetco) cemented using Panavia cement and the crowns were restored with a composite. The specimens in each group were thermocycled for 6000 cycles (5-55°C) and subjected to 1200000 cycles of mechanical loadiong in an artificial mouth machine. Then the fracture strength was measured and data were analyzed using ANOVA and T-student test (α=0.05).
Results: The mean fracture strengths in Hetco group before and after thermomechnical loading were 581.098 ± 192.742 N and 564.74±213.59 N, in Anthogyr group were 664.358 ± 135.878 N and 629.12±390.3 N and, in Svensk group were 780.258 ± 379.133 N and 779.84±282.59 N, respectively. There was no significant difference between groups and also there was no significant difference in each group before and after thermo-mechanical loading (P>0.05).
Conclusion: Restored teeth with Hetco fiber glass post were similar in terms of the fracture strength with that of two other posts after thermo-mechnical loading.
Feizi Ghader , Kaviani Naser , Mehrparvar Roza , Binandeh Elham Sadaat , Tabrizizadeh Mehdi , Saatchi Masoud ,
Volume 27, Issue 4 (1-2015)
Abstract
Background and Aims: Postoperativee endodontic pain is an outstanding problem for dental patients. Therefore, a successful management of endodontic pain has become as one of the main dental objectives. The aim of the present study was to compare the postoperative endodontic pain in patients under general anesthesia versus local anesthesia.
Materials and Methods: For conducting this clinical trial study, 50 patients having mandibular molars candidate for root canal therapy were selected. Twenty-five patients treated under general anesthesia because of their fear, anxiety or gag reflex. Other 25 patients treated under local anesthesia. All teeth were prepared using engine-driven rotary system in a crown-down technique and filled using lateral condensation technique. Heft- parker visual analog scale was used to measure the degree of pain at 6, 12, 24, and 48 hours after the treatment. Mann-Whitney, Chi-square, and T-tests were used to compare the intensity of postoperative pain between the groups.
Results: The mean intensity of postoperative pain in local and general anesthesia groups at 6, 12 and 24 hours had statistically significant difference (P<0.05).
Conclusion: Postoperative pain in patients who treated under general anesthesia was significantly less than the patients who treated under local anesthesia.
Sara Koosha, Ezatolah Jalalian,
Volume 28, Issue 3 (10-2015)
Abstract
Background and Aims: Preserving intact coronal and radicular tooth structure is considered to be crucial for the optimal biomechanical behavior of restored teeth .The ferrule effect has been extensively studied and still remains controversial from many perspectives. The purpose of this study was to summarize the results of different issues related to the ferrule effect and published in journals listed in Pub Med.
Materials and Methods: The search was conducted from 1985-2014 from Pub Med and scientific dentistry internal journals using the following key words: Ferrule, Ferrule effect, Literature review, Fracture resistance, Fatigue, Finite element analysis.
Results: The finding showed that the presence of 1.5-2 mm high and 1mm thickness ferrule had a positive effect on the fracture resistance of endodontically treated teeth.
Conclusion: The presence of ferrule effect is essential for successful endodontic treatment. If a ferrule can performed, the teeth will have poor prognosis for survival.
Nina Rahshenas, Mohammad Hasan Salari, Maryam Koukabi Salehi, Mahshad Mohebbi,
Volume 29, Issue 1 (7-2016)
Abstract
Background and Aims: Debonding at the cement-dentine interface is the main reason of failure in restoration of endodentically treated teeth with fiber posts. The aim of this study was to compare the effect of Starfill 2B danville and Panavia F2 kuraray cements on the retention of fiber posts to root canal dentin.
Materials and Methods: Twenty extracted mandibular premolar teeth which had single root canal were endodentically treated and decoronated. Teeth were randomly divided into 2 groups, (n=40). Fiber posts were cemented using 2 dual cure resin cements. Group A was cemented with Starfill 2B Danville and group B was cemented with Panavia F2 Kuraray. Each root was mounted in acrylic resin and then sliced in 2 parts. The retention strength of each specimen was determined using push-out test using a universal testing machine. Data was analyzed using T-test.
Results: The retentive strength for groups A and B were 48.16±12.11 and 61.44±9.16 MPa, respectively. There was significant difference in the retentive strength between group A and B (P<0.05).
Conclusion: It seems that type of cement had effect on the retention of fiber posts. Panavia F2 Kuraray resin cement significantly provided higher retention than that of Starfill 2B Danville cement.
Arash Zar Bakhsh, Ezzatollah Jalalian, Nilufar Rahimi, Shahrzad Sadr Haghighi,
Volume 29, Issue 1 (7-2016)
Abstract
Background and Aims: The zirconia coated FRC posts (Ice light) is the next generation of aesthetic posts , ice light features 70% fill of zirconia enriched, parallel glass fiber for exceptional strength. Its flexibility is close to dentine so stress is distributed. The aim of this study was to evaluate the effect of post type (FRC post and the zirconia coated FRC post) on the retention to the root canal wall.
Materials and Methods: 20 extracted human premolar teeth with 14 mm length were selected. After post space preparation, the teeth were randomly divided into two groups: Group1: the zirconia coated FRC post (Danville, USA) Group2: FRC post (RTD DT light post, France). All posts were cemented with a dual-cure resin cement (Panavia, Kuraray, Japan). All specimens were mount in acrylic cylinders, and the push-out test was done using a universal testing machine (Instron 5500 R, USA) at 1 mm/min speed. Data were analyzed using T-test.
Results: The retentive strengths were in coronal (75.27+14.81 MPa), in middle (64.38+15.29 MPa) and in apical (51.46+13.29 MPa) for the zirconia coated FRC post, and also were in Coronal (59.16+1.91 MPa), in middle (66.83+12.32 MPa) and in apical (67.88+17.47 MPa) for the FRC post. There was no significant difference in mean retentive strength between two groups in each region (P=0.07).
Conclusion: The FRC post and zirconia coated FRC post had similar retention to the root canal walls.
Marzieh Alikhasi, Amirreza Hendi,
Volume 30, Issue 4 (1-2018)
Abstract
Background and Aims: Loss of retention is one of the main reasons of failure in teeth restored with post and core. Several factors, including the type of cement can influence the retention of the posts. As zinc phosphate cement is considered as the standard for comparison this study performed to review articles evaluating the retention of cast posts cemented with zinc phosphate.
Materials and Methods: This systematic review was performed based on the PRISMA (Transparent Reporting of Systematic Reviews and Meta-analyses) guide. The question of this study was that how much is the amount of retention of cast posts cemented with zinc phosphate. Hence, a literature search was done in PubMed and Medline databases as well as Google scholar search engine using relevant keywords until 2016 limited to the English language. Articles were selected based on the inclusion and exclusion criteria, and were evaluated qualitatively.
Resultes: Internet search resulted in 1141 articles. Following the application of inclusion and exclusion criteria, 6 studies were included in this systematic review. The most common post material was nickel-chromium alloy. Retention of casting posts cemented by zinc phosphate was from 8.76 to 34.2 Kg and from 91 to 192.2 N.
Conclusion: Our review showed that the retention of cast posts cemented with zinc phosphate in controlled condition is moderate and factors including post material and length could influence the retention of the post.
Alireza Parhiz, Forough Fadavi, Siavash Jafari Semnani,
Volume 32, Issue 1 (7-2019)
Abstract
Background and Aims: The aim of this study was to assess the outcome of short implants (<8 mm length) as an alternative to sinus lift surgery and placement of standard-length implants (10-12 mm length) for rehabilitation of atrophic posterior maxilla.
Materials and Methods: In this prospective clinical trial, 26 patients with 6-7 mm of residual alveolar bone height in their atrophic posterior maxilla were randomly divided into two groups (n=13). The test group received short implants without sinus lift surgery while the control group received standard-length implants after maxillary sinus floor augmentation. The bone loss was evaluated at 1 to 2 years after loading of implants on radiographies and the comparison between the two groups was done using chi-square test.
Results: At 1 year, two patients (15.4%) in the short implant and one patient (7.7%) in the standard implant group experienced bone loss (P=0.5). At 2 years, four patients (30.8%) in the short implant and two patients (15.4%) in the standard implant group showed bone loss (P=0.4).
Conclusion: At 2 years after loading, the bone loss was not significantly different around short and standard-length implants. Short implants appeared to be a suitable alternative to sinus lift surgery and placement of standard-length implants for rehabilitation of atrophic posterior maxilla. However, further studies with longer follow ups are still required to cast a final judgment in this respect.
Shahin Shams, Alireza Sharifinejad, Ali Saleh, Pedram Mahmoodi, Abolfazl Mohammadbeigi, Mohammad Mehdizadeh,
Volume 36, Issue 0 (5-2023)
Abstract
Background and Aims: Management of pain and inflammation after third molar surgery is an important challenge of this treatment. Various medications have been proposed for pain control after surgery. Comparing the effectiveness of various drugs used in this field can improve dentists' clinical decisions. The aim of this study was to compare the effect of Ketorolac and Gelofen on pain relief in patients undergoing third molar surgery.
Materials and Methods: This randomized single-blinded clinical trial was performed on 140 patients who were divided into two groups of 70 after receiving the ethical code. The first group was prescribed 400 mg Gelofen capsule for 1 week, while the second group was prescribed 30 mg ketorolac ampule for 1 week. Then, using the visual analog scale (VAS), the patient’s pain was recorded 48 hours, 1 week, and 2 weeks after surgery. Data analysis was carried out using SPSS20 software by descriptive analysis of the results. Ki-square, T-test, and variance analysis were also used for analysis of variables.
Results: The pain level in the ketorolac group after 48 hours, 1 week, and 2 weeks following surgery was significantly less than Gelofen group (P<0.01). Ketorolac effect on pain was irrelevant to the gender, age, and type of tooth variables.
Conclusion: From the results, it was concluded that Ketorolac had greater effect on pain relief after third molar surgery than Gelofen.
Pooya Jannati, Faranak Vakili, Saeid Nokar, Somayeh Zeighami,
Volume 36, Issue 0 (5-2023)
Abstract
Background and Aims: Endocrown is a type of monoblock restoration using the pulp chamber and remaining coronal tooth structure for retention. Advancements in adhesive techniques have breathed fresh spirit into endocrown. Nowadays, there are two approaches for endocrown: conventional approach and biomimetic approach. This study aimed to review data on the steps and clinical and philosophical points of using these approaches to help dentists’ selection and performance.
Materials and Methods: The review was conducted by reviewing the articles available in PubMed, Scopus, and Google Scholar databases from 1995 to 2022. The keywords used were; Crown, Endodontically-treated teeth, Light-curing of dental adhesive, Onlay, and Post-Core.
Results: After removing duplicates, titles/abstracts were reviewed. Animal studies, studies without available full text or non-English language studies were excluded from the study. Then, the full texts of the remaining 59 articles were evaluated and 49 articles were eligible for the present study. The articles included clinical trials, in vitro, systematic reviews, and case reports.
Conclusion: Endocrown is a successful alternative to crown, especially in molar teeth. Regardless of the conventional or biomimetic approach, this treatment has a more favorable fracture pattern while preserving the remaining tooth tissue as much as possible.
Narges Hosseini, Sajad Roshani,
Volume 36, Issue 0 (5-2023)
Abstract
Background and Aims: Dentists are at risk of musculoskeletal disorders due to their job characteristics. The purpose of this study was to compare the posture and musculoskeletal disorders of dentists with high and low work experience.
Materials and Methods: This analytical cross-sectional study research was conducted on 76 dentists in Urmia city. Based on work experience, the samples were divided into two groups: less experienced (less than 15 years) and experienced (15 years and more). The variables of forward head, kyphosis, round shoulder, and musculoskeletal disorders were compared in two groups. Forward head and round shoulder variables were evaluated by photography, kyphosis variable by flexible ruler, and musculoskeletal disorders were evaluated by Nordic questionnaire. Data analysis was done using descriptive statistics and analytical statistics (Kolmogorov-Smirnov test, Leven test, independent t-test and Yeoman-Whitney test).
Results: The independent t-test results showed that the angle of forward head, round shoulder, and kyphosis was higher in the high work-experience group than that of the low work-experience group (P=0.001). In comparing the prevalence of neck disorders, the results were significant such that the experienced group had more neck disorders (P=0.002). However, in examining the difference in the amount of disorders in other parts of the body, the difference between the two groups was not statistically significant (P>0.05).
Conclusion: Experienced dentists had a higher degree of forward head, round shoulder and kyphosis positions. Although, there are musculoskeletal disorders in both groups of dentists with low and high level of experience, neck disorders were more common in high-experienced dentists than that of low-experienced ones.
Abdolrahim Davari, Farnaz Farahat, Haleh Davoudi,
Volume 36, Issue 0 (5-2023)
Abstract
Background and Aims: Insufficient adhesion between fiber post and root canal is the main reason for the failure of the restoration and the fiber post surface treatment can imprive the bond strength. Additionally, there is disagreement about the ideal method of preparation to achieve the desired bond. The aim of this study was to compare the effect of two surface treatment methods on push-out bond strength of fiber posts to root canals.
Materials and Methods: In this study, 45 healthy incisor teeth underwent root canal treatment. After preparing the post space, they were divided into 3 groups of 15, based on the surface treatment methods of the fiber post. In the first group as control group, no surface treatment was done on the fiber post. In the second and third groups, sandblasting with Cojet sand particles and 810 nm diode laser were used for surface treatment, respectively. Then, fiber posts were placed in all root channels by a self-adhesive resin cement. Then, the roots were cut in such a way that from each, 3 pieces with a thickness of 1.5 mm were obtained. Finally, the push-out bond strengths were measured using a universal testing machine. Data were analyzed by ANOVA using SPSS software. The level of significance was considered at P<0.05.
Results: The average bond strengths in three groups were as follows: control group, 2.877 ±1.430, sandblast group 6.318±3.444, and laser 4.224 ±1.890 MPa ± SD. The difference in the bond strength between the sandblast group and the control group was significant (P=0.001). However, the average of the bond strength of laser group was not significantly different from the control group. (P=0.03).
Conclusion: The findings of this study showed that unlike diode laser radiation, the use of Cojet sand particles for sandblasting the fiber post surfaces significanlty improved the bond strength.
Mobina Rahmani, Raheleh Ghaffari, Ebrahim Mohammad Ali Nasab Firouzjah,
Volume 38, Issue 0 (4-2025)
Abstract
Background and Aims: Musculoskeletal disorders are the most common and costly occupational injuries, and dentists are more prone to musculoskeletal problems than other medical professionals. This study aimed to investigate the effect of a course of corrective exercises on the alignment of the thoracic spine and balance in female dentists with increased kyphosis.
Materials and Methods: This research was a quasi-experimental study with a pre-test/post-test design, conducted in the field. Thirty female dentists from Amol and Babol cities (Iran) with increased kyphosis were selected using purposive sampling. The patients were randomly assigned into two groups: control (n=15) and intervention (n=15). In the pre-test, the thoracic curvature angle, static balance, and dynamic balance were assessed using a flexible ruler, the stork balance test, and the Y balance dynamic test, respectively. Then, the intervention group were assigned to perform the exercises for six weeks, while the control group only engaged in daily activities. After completing the exercises, the post-test was conducted. Paired t-tests and analysis of covariance were used to compare intra-group and inter-group differences.
Results: The statistical analysis showed a significant difference between the two groups in the thoracic curvature angle (P=0.001), static balance (P=0.001), and dynamic balance (P=0.001). The intervention group demonstrated significant improvement in these parameters compared to the control group.
Conclusion: Based on the results of this study, it is recommended that corrective exercises under the supervision of a specialist be included in the weekly exercise program of female dentists with increased kyphosis.
