共查询到20条相似文献，搜索用时 31 毫秒
1.
Ersan Çiçek Neslihan Yılmaz M. Murat Koçak Baran Can Sağlam Sibel Koçak Burcu Bilgin 《Journal of endodontics》2017,43(10):1697-1700
Introduction
The aim of this study was to compare the fracture resistance of simulated immature teeth after using different thicknesses of mineral trioxide aggregate (MTA) apical plugs.Methods
Fifty-two human maxillary anterior teeth were used. Five teeth were the positive control group; they were prepared using Peeso reamers to simulate immature teeth without any access cavity preparation. Access cavities of the 47 teeth were prepared, and the canals were instrumented with Peeso reamers. Five teeth served as the negative control; they were filled with calcium hydroxide. Forty-two teeth were divided into 3 groups; in groups 1, 2, and 3, MTA was placed into canals as a 3-mm and a 6-mm apical plug and a thorough canal length, respectively. The rest of the canals in groups 1 and 2 were filled with gutta-percha and AH Plus sealer (Dentsply DeTrey, Konstanz, Germany). After the storage period, the roots were covered with a polyether impression material and were embedded into self-curing resin blocks. Each specimen was then subjected to fracture testing using a universal testing machine. Data were analyzed using 1-way analysis of variance with the Tukey post hoc test for multiple comparisons.Results
The negative group showed the lowest fracture resistance compared with the other groups. The 3-mm apical plug group showed the highest fracture resistance (P < .05). No significant differences were found between the 3-mm and 6-mm apical plug groups (P > .05).Conclusions
MTA should be used as an apical plug instead of root canal filling material to increase the fracture resistance of immature teeth. 相似文献2.
Davoud Jamshidi Hamed Homayouni Nima Moradi Majd Samaneh Shahabi Armita Arvin Baharan Ranjbar Omidi 《Journal of endodontics》2018,44(12):1878-1882
Introduction
Immature necrotic teeth are at a high risk of fracture, especially at the cervical region, after treatment. This study aimed to compare the impact and fracture strength of immature permanent teeth treated with revascularization versus a mineral trioxide aggregate (MTA) plug and fiber post.Methods
This in vitro, experimental study was conducted on 160 maxillary central incisors, which were randomly divided into 10 groups. The groups included a fracture (F) and impact (I) negative control group, F and I positive control groups, F and I MTA groups, F and I revascularizing group, and F and I revascularized groups. Fracture strength was measured using a universal testing machine with a crosshead speed of 1 mm/min. Other tooth samples were then subjected to the Charpy impact test for impact strength measurements, and the amount of energy absorbed by the teeth was determined. Data were analyzed using the Kolmogorov-Smirnov test, analysis of variance, and the Tukey test.Results
The mean load to fracture of the negative, positive, MTA, revacularizing, and revascularized groups was 1931.8, 1350.1, 1003.8, 1262.5, and 1100.2 N, respectively, and the mean impact strength was 5.04, 3.6, 3.68, 3.16, and 3.65 J, respectively. The fracture and impact strength of the negative control group was significantly higher than that of the other groups (P < .05), but the other groups were not significantly different in this respect (P > .05).Conclusions
Despite the limitations of this study, the results showed that none of the tested modalities could significantly increase the impact and fracture strength of simulated immature teeth. 相似文献3.
Sevinç Aktemur Türker Emel Uzunoğlu Derya Deniz Sungur Vildan Tek 《Journal of endodontics》2018,44(5):860-863
Introduction
This study assessed the fracture resistance (FR) of teeth with simulated perforating internal resorption cavities repaired with different calcium silicate–based cements (CSCs) and backfilling materials.Methods
Ninety-six mandibular premolar teeth were used. Twelve of the teeth were assigned as negative control group. Remaining roots were instrumented with rotary files, and standardized internal resorption cavities were prepared on the middle half of roots with burs. Twelve of the samples were not further interfered and were assigned as a positive control group. The apical 4 mm of the remaining 72 root canals was obturated with single-cone technique and divided into 6 groups according to CSCs used for repairing of cavities and backfilling materials as follows: MTA + MTA, MTA + gutta-percha/sealer, Biodentine + Biodentine, Biodentine + gutta-percha/sealer, MTA Plus + MTA Plus, and MTA Plus + gutta-percha/sealer. Specimens were embedded in acrylic resin and then subjected to fracture testing. The forces when the fracture occurred were analyzed with analysis of variance and Bonferroni tests at P = .05.Results
No significant difference was found among CSCs irrespective of backfilling materials (P > .05). Groups MTA + gutta-percha/sealer, Biodentine + gutta-percha/sealer, and MTA Plus + gutta-percha/sealer showed significantly lower FR compared with groups MTA + MTA, Biodentine + Biodentine, and MTA Plus + MTA Plus, respectively (P < .05). The highest FR was observed in group Biodentine + Biodentine, and the lowest was in group MTA Plus + gutta-percha/sealer. FR of positive control group was statistically lower than groups completely filled with CSCs (P < .05), whereas FR of negative control group was statistically higher than the groups combined with gutta-percha and sealer (P < .05).Conclusions
The backfilling with CSCs may be a preferable material rather than gutta-percha/sealer combination for the roots with perforated internal resorptions. 相似文献4.
Introduction
Immature teeth (IT) can be managed by using several treatment options, depending on the vitality of the tooth. The aim of this finite element stress analysis study was to evaluate the effect of different treatment procedures on the stresses in three-dimensional IT models.Methods
Three-dimensional finite element stress analysis premolar tooth model was created as control (model 1), modified to simulate IT. Eleven models were created to simulate IT filled with (model 2) calcium hydroxide (CH), (model 3) mineral trioxide aggregate (MTA), (model 4) Biodentine (B), (models 5 and 6) MTA plug and B plug without root-filling, (models 7 and 8) MTA plug and B plug with root-filling with composite restoration, and amputation by using (model 9) CH, (model 10) MTA, and (model 11) B. Materials and structures were assumed to be homogenous and isotropic. A 300 N load was applied to the models from the functional cusps and central fossa with a 135° angle. Cosmosworks structural analysis program was used. The results were presented considering the von Mises criteria, and the scale range was limited to 0–10 + MPa.Results
CH use in comparison with temporary filling increased the stresses within the root. MTA filling showed less stresses when compared with B filling. MTA and B plug increased the stresses at apical and root; however, when the roots were filled using gutta-percha and the crowns were restored with composite resin, the stresses at the coronal side of the roots were reduced. The stresses were distributed more favorably in the models simulating CH, MTA, or B amputation. Amputation by using MTA and B showed similar stresses with natural tooth model.Conclusions
CH is not a favorable dressing material for IT when compared with MTA and B. MTA or B plug increases the stresses at apical, whereas root-filling reduces the stresses within the root. Amputation by using CH, MTA, and B in combination with composite resin restoration may save both the coronal and root structure of IT. 相似文献5.
Introduction
The purpose of this study was to evaluate the fracture resistance after thermocycling of simulated immature teeth restored with composite, a fiber post, mineral trioxide aggregate (MTA), or gutta-percha.Methods
Eighty-four primary bovine mandibular incisors were divided into 7 groups (n = 12). Negative controls received no treatment. Teeth in all other groups were prepared to an internal diameter of 1.75 mm. After placement of 4-mm apical barrier of MTA, the canals were filled with their respective test materials to the facial cementoenamel junction. For the fiber post group, a fiber post was fitted to extend from the MTA barrier to 2 mm below the incisal edge and was cemented with Build-It FR. The positive controls were left unfilled. The access openings were filled with BisFil II composite. All teeth were then thermocycled for 500 cycles at 5°C and 55°C with a 30-second dwell time and 5-second transfer time. Each root was horizontally fractured through the test material by using an Instron Universal Testing Machine, and the peak load to fracture was recorded. The data were analyzed with analysis of variance and Tukey post hoc tests (P < .05).Results and Conclusions
Thermocycled composite was not significantly stronger than gutta-percha and MTA. The only material that significantly strengthened the simulated immature teeth was the fiber-reinforced composite with a fiber post. 相似文献6.
Warattama Suksaphar Danuchit Banomyong Titalee Jirathanyanatt Yaowaluk Ngoenwiwatkul 《Journal of endodontics》2018,44(2):233-238
Introduction
The aim of the present study was to compare the survival rates against fracture of premolar endodontically treated teeth (ETT) restored with resin composite or crowns and to identify risk factors associated with the fracture.Methods
Data from dental records and radiographs of premolar ETT with postendodontic restorations (ie, resin composite or crowns) were collected between 2012 and 2016 and selected following selected inclusion and exclusion criteria. Tooth location, type of restoration, number of proximal contacts, and amount of tooth surface loss were recorded. The incidence and restorability of postendodontic fractures were identified. Survival rates against fracture of the 2 restoration types were calculated using Kaplan-Meier survival analysis. Any potential factors associated with fractures were identified using Cox proportional hazards models.Results
The survival rate against fracture of ETT restored with crowns (95.1%) was higher than resin composite (77.0%). ETT restored with resin composite with 1 or 2 tooth surface losses and 2 proximal contacts had a high survival rate of 88.5% that was not significantly different from ETT with crowns. A higher incidence of restorability after fracture was observed in teeth restored with resin composite than crowns. The type of restoration and number of proximal contacts were identified as potential risk factors associated with fracture incidence.Conclusions
The survival rate against fracture of ETT restored with crowns was higher than resin composite. However, ETT with 1 or 2 tooth surface losses and 2 proximal contacts and restored with resin composite showed a high survival rate that was comparable with ETT restored with crowns. 相似文献7.
Michael Naumann Guido Sterzenbach Thomas Dietrich Kerstin Bitter Roland Frankenberger Manja von Stein-Lausnitz 《Journal of endodontics》2017,43(11):1770-1775
Introduction
This is the first long-term randomized controlled trial to evaluate dentin-like glass fiber posts (GFPs) compared with rather rigid titanium posts (TPs) for post-endodontic restoration of severely damaged endodontically treated teeth with 2 or fewer remaining cavity walls.Methods
Ninety-one subjects in need of post-endodontic restorations were randomly assigned to receive either a tapered GFP (n = 45) or TP (n = 46). Posts were adhesively luted by using self-adhesive resin cement, followed by composite core build-up and preparation of 2-mm ferrule design. Primary end point was loss of restoration for any reason. Kaplan-Meier curves were constructed, and log-rank test was calculated (P < .05).Results
After a follow-up of 132 months, 17 GFP and 20 TP restorations survived, and 19 failed (12 GFP, 7 TP). Failure modes for GFP were root fracture (n = 4), core fracture (n = 1), secondary caries (n = 1), endodontic failure (n = 2), extraction because of tooth mobility grade III associated with insufficient design of removable partial denture (n = 1), tooth fracture (n = 1), and changes in treatment plan (n = 2); failure modes for TP were endodontic failure (n = 5), root fracture (n = 1), and 1 extraction for other reasons. Cumulative survival probability was 58.7% for GFP and 74.2% for TP.Conclusions
When using self-adhesively luted prefabricated posts, resin composite core build-up, and 2-mm ferrule to reconstruct severely damaged endodontically treated teeth, tooth survival is not influenced by post rigidity. Survival decreased rapidly after 8 years of observation in both groups. 相似文献8.
Taha Özyürek Özlem Ülker Ebru Özsezer Demiryürek Fikret Yılmaz 《Journal of endodontics》2018,44(5):800-805
Introduction
The aim of this study was to compare the fracture strengths of mandibular molar teeth prepared using traditional endodontic cavity (TEC) and conservative endodontic cavity (CEC) methods and restored using SDR (Dentsply Caulk, Milford, DE) and EverX Posterior (GC Dental, Tokyo, Japan) base composite materials.Methods
A hundred mandibular first molar teeth were randomly divided into 5 groups. In group 1 (the control group), samples were kept intact. In group 2, TECs were prepared, and the samples were restored with EverX Posterior and composite resin. In group 3, CECs were prepared, and the samples were restored with EverX Posterior and composite resin. In group 4, TECs were prepared, and the samples were restored with SDR and composite resin. In group 5, CECs were prepared, and the samples were restored with SDR and composite resin. This load was applied on the samples at 1-mm/min speed using a 6-mm round-head tip until fracture. The forces resulting in fracture were recorded in newton units. The data were analyzed using Kruskal-Wallis and Pearson correlation tests at a 5% significance level.Results
The fracture strengths of the samples in the control group were significantly higher than the experimental groups (P < .05). There was no statistically significant difference in the endodontic access cavities prepared used the TEC and CEC methods and restored using the same composite base material (P > .05).Conclusions
CEC preparation did not increase the fracture strength of teeth with class II cavities compared with TEC preparation. The fracture strength of teeth restored with the SDR bulk-fill composite was higher than that of teeth restored with EverX Posterior. 相似文献9.
Introduction
Maxillary premolars are among the teeth most susceptible to vertical root fracture (VRF) from lateral condensation of gutta-percha. These teeth are distinguished by a complex anatomy of the buccal root including a large depression in the dentin wall facing the bifurcation. It is hypothesized that tooth sectioning coupled with 2-dimensional fracture analysis is instrumental in understanding VRF in such teeth. VRF was examined by tooth sectioning following the development of a fracture mechanics analysis to predict VRF in such roots.Methods
The fracture morphology in teeth extracted from patients because of VRFs was examined from a series of horizontal cross sections. 2-dimensional fracture mechanics analysis in conjunction with the finite element technique was developed to evaluate VRF caused by canal pressure (q). As in our previous single-rooted tooth model, the apical obturation force (F) was related to q using a simple formula.Results
Fracture was mostly limited to the buccal root, exhibiting some competing modes including fracture from the depression peak to the canal surface and the canal surface to the root surface, which may occur either along straight lines or curved trajectories resembling the depression outline. The analysis predicted clinical fractures well, yielding VRF force values in the upper range used by clinicians during lateral condensation of gutta-percha.Conclusions
The main etiology for VRF is stress concentration resulting from the combined effect of wedgelike canal depression and the flexibility of periodontal ligament tissue joining the root and bone. This drawback can be alleviated by minimizing canal enlargement and apical condensation force during root canal therapy. 相似文献10.
Victor Aquino Wanderley Deborah Queiroz Freitas Francisco Haiter-Neto Matheus Lima Oliveira 《Journal of endodontics》2018,44(7):1168-1172
Introduction
The purpose of this study was to assess the influence of tooth orientation in relation to the projection plane of the x-rays on the detection of vertical root fracture (VRF) with different filling materials using cone-beam computed tomographic (CBCT) imaging.Methods
Thirty single-rooted human teeth were endodontically instrumented, and VRF was induced in half of the sample. The roots were individually placed in the dental socket of a phantom head composed of a dry human skull and mandible, and CBCT images were obtained of each root with the longitudinal axis in 2 orientations: perpendicular and parallel to the projection plane of the x-rays. Also, each root was scanned under 3 filling conditions: without filling material, with gutta-percha, and with a metal post. Radiation doses at specific anatomic regions of the phantom were obtained for the 2 orientations. Five radiologists evaluated all images and rated the fractures on a 5-point scale. The sensitivity, specificity, accuracy, and positive and negative predictive values were calculated. The area under the receiver operating characteristic curve and the dosimetric outcomes for each root orientation and filling material were compared, respectively, with 2-way and 1-way analysis of variance with the post hoc Tukey test (α = 0.05).Results
There was no significant difference (P ≥ .05) in the detection of VRF between root orientations regardless of the filling material. Az values were significantly lower (P < .05) in the presence of gutta-percha and a metal post. The root orientation varied the absorbed dose at some anatomic regions.Conclusions
The orientation of the tooth in relation to the projection plane of the x-rays does not influence the detection of VRF using CBCT imaging irrespective of the intracanal material. 相似文献11.
Introduction
The purpose of this study was to evaluate the gap volume between dentin and root-end filling materials.Methods
Four root-end filling materials were compared in the present study: ProRoot MTA (PRM; Dentsply Tulsa Dental, Tulsa, OK), MTA Angelus (MAG; Angelus, Londrina, Brazil), EndoCem MTA (ECM; Maruchi, Wonju, Korea), and RetroMTA (RTM; BioMTA, Seoul, Korea). Forty-eight single-rooted, extracted human teeth were instrumented with nickel-titanium instruments and oburated with gutta-percha. The apical 3 mm of the root tip was resected, and root-end preparation was performed with a diamond bur. The root-end cavity was filled with the experimental filling materials for the 4 designated groups (n = 10). Then, the samples were scanned with micro–computed tomographic (micro-CT) imaging. Three-dimensional images of the samples were reconstructed, and the volume of the gap between the tooth surface (dentinal wall) and the root-end filling materials was measured. The percentage volume of the gap between the tooth structure and the root-end filling material (VG%) was calculated. Data were analyzed using the Kruskal-Wallis and Mann-Whitney U tests at a significance level of 95%.Results
The median VG% values for the PRM, MAG, ECM, and RTM groups were 0.00472, 0.00134, 0.00014, and 0.00071, respectively. The ProRoot MTA group showed the greatest gap volume percentage among the experimental groups with a significant statistical difference (P < .05).Conclusions
From the micro-CT analysis, ProRoot MTA had a greater gap volume percentage than other root-end filling materials. 相似文献12.
Lama Awawdeh Aladdin Al-Qudah Hanan Hamouri Rosalie Jean Chakra 《Journal of endodontics》2018,44(11):1603-1609
Introduction
Mineral trioxide aggregate (MTA) has been used in pulp capping of cariously exposed mature permanent teeth with promising results. The search for alternative materials that seal better and set faster than MTA and do not stain is ongoing. Biodentine (Septodont, St Maur-des-Fossés, France) exhibits these advantages but has not been tested yet for a prolonged duration in mature teeth. This study aimed to evaluate the clinical performance of Biodentine and white MTA (Angelus, Londrina, Brazil) in cariously exposed mature permanent teeth.Methods
This was a prospective longitudinal randomized controlled study of 68 vital permanent teeth with deep caries. Patients were randomly allocated into 2 study arms: Biodentine and MTA. Teeth were assessed clinically and radiographically before the procedure. Caries were excavated under local anesthesia; hemostasis was achieved after pulp exposure using sodium hypochlorite and capped with Biodentine or MTA. Clinical and radiographic follow-ups were performed by a blinded calibrated evaluator after 6 months and 1, 2, and 3 years.Results
There were no significant differences in the overall success rate between Biodentine and MTA; it was 93.3% (Biodentine = 93.1% and MTA = 93.5%) at 6 months. The overall success rate increased to 96.2% (Biodentine = 96.0% and MTA = 100%) at 1 year and to 100% at 2 years. At the 3-year follow-up, it decreased to 93.8% (Biodentine = 91.7% and MTA = 96.0%).Conclusions
Biodentine and MTA have favorable and comparable success rates when used as direct pulp capping or pulpotomy material in permanent mature teeth with carious exposure. The remaining tooth structure and durability of coronal restoration might affect significantly the long-term success of vital pulp therapy. 相似文献13.
Jiacheng Lin Qian Zeng Xi Wei Wei Zhao Minyi Cui Jing Gu Jiaxuan Lu Maobin Yang Junqi Ling 《Journal of endodontics》2017,43(11):1821-1827
Introduction
The aim of the study was to compare the outcomes of regenerative endodontic treatment (RET) and apexification on immature permanent teeth with pulp necrosis and apical periodontitis.Methods
A total of 118 patients (118 teeth) were recruited and randomly assigned to either RET or apexification treatment. Each treatment group was divided into 2 subgroups according to the etiology: dens evaginatus or trauma. Clinical symptoms and complications were recorded, and cone-beam computed tomographic imaging with a limited field of view was used to measure the change of root length, root thickness, and apical foramen size at the 12-month follow-up. The t test/rank sum test and Fisher exact test were applied to compare the change of root morphology between RET and apexification.Results
One hundred three of 118 cases were completed at the 12-month follow-up. The survival rate was 100% for both treatment groups. All cases were asymptomatic with apical healing. The RET group showed a significant increase in root length and root thickness compared with the apexification group (P < .05). In the RET group, the cases caused by dens evaginatus achieved increased root length and root thickness compared with those caused by trauma (P < .05).Conclusions
RET and apexification achieved a comparable outcome in regard to the resolution of symptoms and apical healing. RET showed a better outcome than apexification regarding increased root thickness and root length. The etiology had an impact on the outcome of RET. Dens evaginatus cases showed better prognoses than trauma cases after RET. 相似文献14.
Wei Zhou Qinghua Zheng Xuelian Tan Dongzhe Song Lan Zhang Dingming Huang 《Journal of endodontics》2017,43(1):1-6
Introduction
This prospective randomized controlled study evaluated the clinical and radiographic outcome of endodontic microsurgery when using iRoot BP Plus Root Repair Material (BP-RRM; Innovative BioCeramix Inc, Vancouver, BC, Canada) or mineral trioxide aggregate (MTA) as the retrograde filling material and analyzed the relationship between some potential prognostic factors and the outcome of the surgery.Methods
By using strict inclusion and exclusion criteria, 240 teeth were successfully enrolled and randomly and equally allocated to either the MTA or BP-RRM treatment group. A standardized surgical procedure was performed by a single operator. The patients were followed up at 1 week, 3 months, 6 months, and 12 months; follow-up included clinical and radiographic examination. Clinical and radiographic evaluations acquired at the 12-month follow-up were taken as the primary outcome. For the identification of prognostic factors, the dichotomous outcome (success vs failure) was taken as the dependent variable.Results
A total of 158 teeth were analyzed at the 12-month follow-up, including 87 teeth in the MTA group and 71 teeth in the BP-RRM group. The success rate in the MTA and BP-RRM groups was 93.1% (81/87 teeth) and 94.4% (67/71 teeth), respectively (P > .05). Three significant outcome predictors were identified: quality of root filling (P < .05), tooth type (P < .05), and size of the lesion (P < .05)Conclusions
These results suggest that BP-RRM is comparable with MTA in clinical outcome when used as root-end filling materials in endodontic microsurgery. 相似文献15.
Priscilla Cardoso Lazari Marco Aurélio de Carvalho Altair A. Del Bel Cury Pascal Magne 《The Journal of prosthetic dentistry》2018,119(5):769-776
Statement of problem
Which post-and-core combination will best improve the performance of extensively damaged endodontically treated incisors without a ferrule is still unclear.Purpose
The purpose of this in vitro study was to investigate the restoration of extensively damaged endodontically treated incisors without a ferrule using glass-ceramic crowns bonded to various composite resin foundation restorations and 2 types of posts.Material and methods
Sixty decoronated endodontically treated bovine incisors without a ferrule were divided into 4 groups and restored with various post-and-core foundation restorations. NfPfB=no-ferrule (Nf) with glass-fiber post (Pf) and bulk-fill resin foundation restoration (B); NfPfP=no-ferrule (Nf) with glass-fiber post (Pf) and dual-polymerized composite resin core foundation restoration (P); NfPt=no-ferrule (Nf) with titanium post (Pt) and resin core foundation restoration; and NfPtB=no-ferrule (Nf) with titanium post (Pt) and bulk-fill resin core foundation restoration (B). Two additional groups from previously published data from the same authors (FPf=2mm of ferrule (F) and glass-fiber post (Pf) and composite resin core foundation restoration; and NfPf=no-ferrule (Nf) with glass-fiber post (Pf) and composite resin core foundation restoration), which were tested concomitantly and using the same experimental arrangement, were included for comparison. All teeth were prepared to receive bonded glass-ceramic crowns luted with dual-polymerized resin cement and were subjected to accelerated fatigue testing under submerged conditions at room temperature. Cyclic isometric loading was applied to the incisal edge at an angle of 30 degrees with a frequency of 5 Hz, beginning with a load of 100 N (5000 cycles). A 100-N load increase was applied every 15 000 cycles. The specimens were loaded until failure or to a maximum of 1000 N (140 000 cycles). The 6 groups (4 groups from the present study and 2 groups from the previously published study) were compared using the Kaplan-Meier survival analysis (log-rank post hoc test at α=.05 for pairwise comparisons).Results
None of the tested specimen withstood all 140?000 cycles. All specimens without a ferrule were affected by an initial failure phenomenon (wide gap at the lingual margin between the core foundation restoration/crown assembly and the root). NfPfP, NfPt, and NfPtB had similar survival (29 649 to 30 987 mean cycles until initial failure). NfPfB outperformed NfPt and NfPtB. None of the post-and-core foundation restoration materials were able to match the performance of the ferrule group FPf (72 667 cycles). In all groups, 100% of failures were catastrophic.Conclusions
The survival of extensively damaged endodontically treated incisors without a ferrule was slightly improved by the use of a fiber post with a bulk-fill composite resin core foundation restoration. However, none of the post-and-core techniques was able to compensate for the absence of a ferrule. The presence of the posts always adversely affected the failure mode. 相似文献16.
Eduardo A. Caceres Camila S. Sampaio Pablo J. Atria Helora Moura Marcelo Giannini Paulo G. Coelho Ronaldo Hirata 《The Journal of prosthetic dentistry》2018,119(1):103-107
Statement of problem
Few studies have investigated the voids and gaps produced during the cementation of fiber posts using different techniques.Purpose
The purpose of this study was to evaluate and quantify void and gap area formations of different fiber post cementation techniques using microcomputed tomography (μCT).Material and methods
Standardized endodontically treated acrylic resin roots (N=24) were divided into 4 groups (n=6) according to different fiber posts cemented with the resin cement (FB); fiber posts relined with composite resin followed by cementation (FBR); fiber posts cemented using an ultrasonic device (FBU); and fiber posts relined with composite resin and cemented using an ultrasonic device (FBRU). Each specimen was scanned twice using micro-computed tomography (μCT; empty root, followed by after fiber post cementation). Digital imaging and communications in medicine (DICOM) files were transferred into 3-dimensional (3D) reconstruction software for analysis. Void volume in the cementation system and gap area formation were evaluated; quantitative and qualitative analyses were performed. The data were analyzed using 2-way ANOVA and the Tukey honest significant difference post hoc test (α=.05).Results
FBR showed a lower percentage of voids than obtained for FB (P<.05). Groups FB, FBU, and FBRU did not show significant difference in void formation (P>.05). No significant differences were found in gap area formations among the experimental groups (P>.05).Conclusions
The use of a composite resin to reline the fiber post significantly decreased the void formation in the cementation procedure when no ultrasonic device was used. The use of an ultrasonic device did not decrease the percentage of void or gap formation for any technique evaluated. 相似文献17.
Domingo Santos Pantaleón Brian R. Morrow David R. Cagna Cornelis H. Pameijer Franklin Garcia-Godoy 《The Journal of prosthetic dentistry》2018,119(3):390-396
Statement of problem
Limited information is available on the effect of an incomplete ferrule because of the varying residual axial wall heights and the volume of residual tooth structure on the fracture resistance of endodontically treated and restored maxillary incisors.Purpose
The purpose of this in vitro investigation was to examine the effect of varying residual axial wall heights, residual coronal tooth structure, and the absence of 1 proximal axial wall on the fracture resistance and failure mode of endodontically treated teeth restored with metal posts.Material and methods
Sixty intact human maxillary central incisors were divided into 6 groups (n=10): no ferrule (NF), 2-mm complete ferrule (CF2), 2-mm (IF2), 3-mm (IF3), and 4-mm (IF4) incomplete ferrules missing a single interproximal wall, and a control group that had a 6-mm incomplete ferrule (IF6). Cast metal post-and-cores were placed in all experimental specimens except for controls. Control specimens received 1 interproximal cavity preparation extending to the root canal access and a composite resin restoration. Complete metal crowns were then cemented on all specimens. Completed specimens were subjected to thermocycling (6000 cycles, 5°C/55°C) followed by the immediate testing of fracture resistance. Failed specimens were sectioned buccolingually and evaluated to identify the failure mode. The data were analyzed with an analysis of variance (ANOVA) and the Student-Newman-Keuls multiple comparison test (α=.05).Results
An incomplete ferrule (IF2) with 1 interproximal wall missing had significantly reduced fracture resistance (697 N) compared with a complete ferrule (932 N). An increase of 3 to 4 mm of remaining wall height improved fracture resistance, from 844 N (IF3) to 853 N (IF4). Partial decementation was noticed in 8 NF and 5 IF2 specimens. IF3 and IF4 had no decementations. Radicular fractures and cracks (catastrophic failure) were observed in all IF2, IF3, and IF4, 9 CF2, and 6 NF specimens. In 7 specimens without posts (IF6, control), composite resin foundation and/or coronal dentin fracture were observed and the failure was considered repairable.Conclusions
The results of this in vitro study indicated that specimens with a 2-mm ferrule of uniform height were more resistant to fracture than specimens with a 2-mm ferrule and 1 missing interproximal wall. An increased wall height of 3 or 4 mm was associated with a significant increase in fracture resistance and can compensate for the missing interproximal wall. 相似文献18.
Nuttaporn Parinyaprom Areerat Nirunsittirat Patchanee Chuveera Sakarat Na Lampang Tanida Srisuwan Thanapat Sastraruji Puangporn Bua-on Sophon Simprasert Issaraporn Khoipanich Thitida Sutharaphan Suthida Theppimarn Narumol Ue-srichai Waritorn Tangtrakooljaroen Papimon Chompu-inwai 《Journal of endodontics》2018,44(3):341-348
Introduction
This study aimed to compare the success rates of direct pulp capping (DPC) by using either ProRoot Mineral Trioxide Aggregate (MTA) or Biodentine in the cariously exposed permanent teeth of 6- to 18-year-old patients. Gray discoloration was also evaluated.Methods
Fifty-nine cariously exposed permanent teeth, including teeth with diagnosis of normal pulp, reversible pulpitis, or irreversible pulpitis, early periapical involvement, and exposure size of up to 2.5 mm, were included. Each patient with only 1 cariously exposed tooth was randomly allocated to DPC with either ProRoot MTA (n = 30) or Biodentine (n = 29). Patients were recalled every 6 months. Clinical and radiographic examinations were used to determine success.Results
Fifty-five patients (mean age, 10 ± 2 years), 27 treated with ProRoot MTA and 28 with Biodentine, were included in the analysis. At mean follow-up of 18.9 ± 12.9 months, the success rate was 92.6% with ProRoot MTA and 96.4% with Biodentine (P > .05; difference, 4%; 95% confidence interval [CI], –8% to 16%). Biodentine was non-inferior to ProRoot MTA. Failures were distributed equally in all categories of pulpal diagnosis and occurred in teeth with no periapical involvement and small exposures (0.5 mm). The survival probabilities of DPC with ProRoot MTA and Biodentine were 0.92 (95% CI, 0.73–0.98) and 0.96 (95% CI, 0.80–0.99). No significant difference was observed between them (P > .05). Gray discoloration was observed only with ProRoot MTA (55%).Conclusions
Biodentine was non-inferior to ProRoot MTA when used as a DPC material for cariously exposed permanent teeth of 6- to 18-year-old patients. However, Biodentine did not cause any gray discoloration in this study. 相似文献19.