Fracture resistance of upper central incisors restored with different posts and cores

Saeid Tavanafar,,Kamran Amirian Chaijan,Saeid Tavanafar 대한치과보존학회 2015 Restorative Dentistry & Endodontics Vol.40 No.3

Objectives: To determine and compare the fracture resistance of endodontically treated maxillary central incisors restored with different posts and cores. Materials and Methods: Forty-eight upper central incisors were randomly divided into four groups: cast post and core (group 1), fiber-reinforced composite (FRC) post and composite core (group 2), composite post and core (group 3), and controls (group 4). Mesio-distal and bucco-lingual dimensions at 7 and 14 mm from the apex were compared to ensure standardization among the groups. Twelve teeth were prepared for crown restoration (group 4). Teeth in other groups were endodontically treated, decoronated at 14 mm from the apex, and prepared for posts and cores. Resin-based materials were used for cementation in groups 1 and 2. In group 3, composite was used directly to fill the post space and for core build-up. All samples were restored by standard metal crowns using glass ionomer cement, mounted at 135° vertical angle, subjected to thermomechanical aging, and then fractured using a universal testing machine. Kruskal-Wallis and Mann-Whitney U tests were used to analyze the data. Results: Fracture resistance of the groups was as follows: Control (group 4) > cast post and core (group 1) > fiber post and composite core (group 2) > composite post and core (group 3). All samples in groups 2 and 3 fractured in restorable patterns, whereas most (58%) in group 1 were non-restorable. Conclusions: Within the limitations of this study, FRC posts showed acceptable fracture resistance with favorable fracture patterns for reconstruction of upper central incisors.

Influence of operator's experience level on lifespan of the WaveOne Primary file in extracted teeth

Abdulrahman Mohammed Saleh,,Saeid Tavanafar,,Pouyan Vakili-Gilani,Noor Jamal Al Sammerraie,Faahim Rashid 대한치과보존학회 2013 Restorative Dentistry & Endodontics Vol.38 No.4

Objectives: The aim of this study was to assess the influence of operator experiencelevel on the lifespan of the WaveOne Primary file (Dentsply Maillefer, Ballaigues,Switzerland) in extracted teeth. Materials and Methods: Moderately curved canals ofextracted maxillary and mandibular molars were randomly distributed into 2 groups:experienced and inexperienced operators. Ten files were allocated to each group (n =10). Each canal was prepared until the working length was reached, and the same filewas used to prepare additional canals until it separated. The number of canals preparedbefore file separation was recorded. The fragment length of each file was measured,and the location of the fragment in the canal was determined. Data were statisticallyanalysed using the independent 2-sample t-test. Results: The 2 operators prepared atotal of 324 moderately curved canals of maxillary and mandibular molars. There wasno significant intergroup difference in the mean number of canals prepared (p = 0.27). The average lifespan of the WaveOne Primary file was 17.1 and 15.3 canals, and thelongest lifespan was 25 and 20 canals, when used by experienced and inexperiencedoperators, respectively. There were no statistically significant intergroup differencesin separated fragment length and location. Conclusions: Within the limitations ofthis study, operator experience level appears to have no effect on the lifespan of theWaveOne Primary file in preparation of moderately curved canals. Single teeth withmultiple canals can be prepared safely even by a novice operator by using a single file.

Influence of operator's experience level on lifespan of the WaveOne Primary file in extracted teeth

Saleh, Abdulrahman Mohammed,Tavanafar, Saeid,Vakili-Gilani, Pouyan,Al Sammerraie, Noor Jamal,Rashid, Faahim The Korean Academy of Conservative Dentistry 2013 Restorative Dentistry & Endodontics Vol.38 No.4

Objectives: The aim of this study was to assess the influence of operator experience level on the lifespan of the WaveOne Primary file (Dentsply Maillefer, Ballaigues, Switzerland) in extracted teeth. Materials and Methods: Moderately curved canals of extracted maxillary and mandibular molars were randomly distributed into 2 groups: experienced and inexperienced operators. Ten files were allocated to each group (n = 10). Each canal was prepared until the working length was reached, and the same file was used to prepare additional canals until it separated. The number of canals prepared before file separation was recorded. The fragment length of each file was measured, and the location of the fragment in the canal was determined. Data were statistically analysed using the independent 2-sample t-test. Results: The 2 operators prepared a total of 324 moderately curved canals of maxillary and mandibular molars. There was no significant intergroup difference in the mean number of canals prepared (p = 0.27). The average lifespan of the WaveOne Primary file was 17.1 and 15.3 canals, and the longest lifespan was 25 and 20 canals, when used by experienced and inexperienced operators, respectively. There were no statistically significant intergroup differences in separated fragment length and location. Conclusions: Within the limitations of this study, operator experience level appears to have no effect on the lifespan of the WaveOne Primary file in preparation of moderately curved canals. Single teeth with multiple canals can be prepared safely even by a novice operator by using a single file.

Fracture resistance of upper central incisors restored with different posts and cores

Rezaei Dastjerdi, Maryam,Amirian Chaijan, Kamran,Tavanafar, Saeid The Korean Academy of Conservative Dentistry 2015 Restorative Dentistry & Endodontics Vol.40 No.3

Objectives: To determine and compare the fracture resistance of endodontically treated maxillary central incisors restored with different posts and cores. Materials and Methods: Forty-eight upper central incisors were randomly divided into four groups: cast post and core (group 1), fiber-reinforced composite (FRC) post and composite core (group 2), composite post and core (group 3), and controls (group 4). Mesio-distal and bucco-lingual dimensions at 7 and 14 mm from the apex were compared to ensure standardization among the groups. Twelve teeth were prepared for crown restoration (group 4). Teeth in other groups were endodontically treated, decoronated at 14 mm from the apex, and prepared for posts and cores. Resin-based materials were used for cementation in groups 1 and 2. In group 3, composite was used directly to fill the post space and for core build-up. All samples were restored by standard metal crowns using glass ionomer cement, mounted at $135^{\circ}$ vertical angle, subjected to thermo-mechanical aging, and then fractured using a universal testing machine. Kruskal-Wallis and Mann-Whitney U tests were used to analyze the data. Results: Fracture resistance of the groups was as follows: Control (group 4) > cast post and core (group 1) > fiber post and composite core (group 2) > composite post and core (group 3). All samples in groups 2 and 3 fractured in restorable patterns, whereas most (58%) in group 1 were non-restorable. Conclusions: Within the limitations of this study, FRC posts showed acceptable fracture resistance with favorable fracture patterns for reconstruction of upper central incisors.

Does the systemic administration of l-arginine affect dental implant stability in nicotine consumer dogs?

Movahedian Bijan,Rismanchian Mansour,Navaei Hooman,Tavanafar Saeid,Koushaei Soheil 대한악안면성형재건외과학회 2021 Maxillofacial Plastic Reconstructive Surgery Vol.43 No.-

Nicotine can have detrimental effects on dental implant osseointegration. This study aimed to evaluate the influence of systemic l -arginine supplement on the osseointegration of dental implants in nicotine consumer dogs. Twelve 1-year Labrador Retriever dogs had their right and left third and fourth mandibular premolars removed, and the sockets were left to heal for 6 months. Dogs were randomly divided into three groups ( n = 16): group 1—0.2 mg/kg nicotine was injected twice daily; group 2—0.2 mg/kg nicotine was injected twice daily in addition to 200 mg/kg l -arginine capsules taken orally; and group 3—placebo. Forty-eight dental implants were inserted into the healed sockets of the dog’s mandible and were assessed by implant stability quotient (ISQ) using resonance frequency analysis (RFA) during 4 weeks and insertion and removal torque value analysis. No implant failure occurred during the study period. The change in torque value between insertion and removal was similar in the placebo and nicotine+arginine consumer dogs ( p = 0.276), which shows a positive effect of arginine supplementation in nicotine consumers. There was a significant difference in torque value change between nicotine+arginine vs. nicotine consumers ( p = 0.049) and placebo vs. nicotine ( p = 0.003). After 4 weeks, the placebo had the most significant improvement in torque value (47.0 ± 16.9), followed by nicotine+arginine (25.1 ± 37.8), and the worst torque value was for the nicotine group (− 5.7 ± 24.0) pound per inch. The results show that except in the first week, there are significant differences in ISQ between the groups in different periods. ISQ in all of the groups has reduced at first but then increased over time. At the time of implant placement, insertion torque was significantly higher in the nicotine consumer group than the nicotine+arginine consumer group and placebo group ( p = 0.020). Arginine supplementation promotes bone healing and implant primary stability by improving dental implant osseointegration biomechanical characteristics.

The effects of orthognathic surgery on auditory function

Farhad Ghorbani,Hossein Danesteh,Afshin Khoramnia,Saeid Tavanafar 대한악안면성형재건외과학회 2021 Maxillofacial Plastic Reconstructive Surgery Vol.43 No.-

BackgroundOrthognathic surgery is widely used in treating functional and skeletal problems. Any surgical procedure could cause side effects. ObjectivesThis study aimed to evaluate the potential changes in orthognathic surgery on the hearing function of patients. Materials and methodsThirty-one orthognathic surgery candidates were recruited in this study. Patients underwent either single or double jaw surgery. Pure tone audiometry (PTA), tympanometry, and Eustachian Tube Dysfunction Test (ETFT) were performed postoperatively at 24 h, 6 weeks, and 6 months after surgery. Patients were tabulated based on the type of maxilla and mandibular surgical movements (vertical and horizontal). ResultsPTA evaluation, based on horizontal or vertical movements, did not show significant differences, although vertical movements resulted in less change in hearing threshold. In other words, no significant changes occurred in patients’ hearing threshold after surgery. No significant difference was also observed between horizontal and vertical movements in the results of tympanometry. Negative changes were found in the results of ETFT in vertical movements, which returned to pre-surgery values in the final test. ConclusionsThe risk of minor changes in hearing function is probable during the first week after orthognathic surgery, but these negative changes will either totally fade or remain negligible. Patients gave informed consent preoperatively, and reassurance postoperatively is prudent.

Analysis of hard tissue facial symmetry after unilateral mandibular reconstruction

Mohamad Saleh Khaghaninejad,Leila Khojastepour,Hanie Ahmadi,Saeid Tavanafar,Alireza Ebrahimi,Mohammad Mahjoori-Ghasrodashti 대한악안면성형재건외과학회 2021 Maxillofacial Plastic Reconstructive Surgery Vol.43 No.-

BackgroundThis study aimed to determine how successful reconstruction of the mandible can recover the symmetry. Materials and methodsAll patients who underwent surgical treatment for unilateral mandibular reconstruction in 4 years were retrospectively examined. Bilateral differences of gonion (GO) positions were measured in 3 dimensions based on immediate postoperative computed tomography. The data collected was analyzed in 3 ways: First, the comparison of bilateral differences of GO in 3 dimensions. Second, the mean Asymmetry Index in control subjects was used to divide all cases into three groups: “Symmetry,” “Asymmetry,” and “Marked asymmetry.” Third, “maximum normal asymmetry” was calculated, and all cases were categorized as below and above maximum normal asymmetry. The difference between two gonial angles was used to determine the amount of asymmetry. ResultsForty-seven patients and 47 normal adults were enrolled. The mean bilateral GO difference in the control group was higher than in the study group patients, but it was not statistically significant. The mean Asymmetry Index for the control group was not also significantly higher than the study cases. The study group was “Symmetric” in 78.7% of the cases whereas the control group in 91.4%, 19.1% of the study group and 8.5% of controls were “Asymmetric,” and 2.1% of study cases and 0% of controls were “Markedly Asymmetric.” Maximum normal asymmetry was 82.9% in the study group and 97.8% in the control group. The mean differences between the right and left gonial angles were higher in the study group, but it was not significant (P = 0.1). ConclusionsOur study’s results showed that bilateral symmetry in mandibular reconstruction patients was satisfactory and similar to the normal individuals.