Single crown vs. composite for glass fiber post-retained restorations: An 8-year randomized clinical trial.

OBJECTIVES: This study aimed to compare the success and survival rates of metal-ceramic crowns and composite resin restorations applied in root filled teeth that received a glass fiber post. METHODS: A prospective, randomized controlled trial, with equivalent parallel groups was designed. Eighty-two teeth were randomly allocated to the metal-ceramic or composite resin groups. Multivariate Cox regression analysis with shared frailty for patients and Kaplan-Meier curves were performed using success and survival rates (p<0.05). RESULTS: Seventy-five post-retained restorations (34 metal-ceramic crowns and 41 composite restorations) in 62 patients were analyzed. The median follow-up was 8.1 years [IQR 4.0-9.9]. Twenty-seven failures were observed. Twenty-two failures (81.5 %) were observed in the composite resin group, of which six (27.3 %) were not repairable. Five failures (18.5 %) were observed in the metal-ceramic crown group, of which three (66.6 %) were non-repairable. The cumulative success rate at 8 years was 85.0 % for crowns (AFR=1.31 %) and 43.2 % for composite resins (AFR=6.58 %), while the survival rate was 93.8 % for crowns (AFR=0.52 %) and 97.6 % for composite resins (AFR=0.20 %). Considering the success rates, adjusted multivariate Cox regression showed that composite resin had a Hazard Ratio of 5.07 (95 %CI, 1.99-12.89) greater than the metal-ceramic crown. No significant difference in the failure risk was observed when the survival rates were considered (HR=0.38, 95 %CI (0.10 - 1.44), p = 0.156). Co-variables did not affect the success and survival rates (p>0.05). CONCLUSIONS: Metal-ceramic crowns showed a higher success rate than composite restorations. The survival rates were similar, but composite restorations presented a higher need for repairs. CLINICAL SIGNIFICANCE: Post-retained composite restorations may need more reinterventions during the lifecycle, although more preservation of sound tooth structure is expected with a large restoration of resin post-and-core. These aspects have to be discussed with the patient for decision-making planning.

Fatigue performance of endodontically treated premolars restored with direct and indirect cuspal coverage restorations utilizing fiber-reinforced cores.

OBJECTIVES: The aim of this in vitro study was to investigate the fatigue survival and fracture behavior of endodontically treated (ET) premolars restored with different types of post-core and cuspal coverage restorations. MATERIALS AND METHODS: MOD cavities were prepared on 108 extracted maxillary premolars. During the endodontic treatment, all teeth were instrumented with rotary files (ProTaper Universal) to the same apical enlargement (F2) and were obturated with a matched single cone obturation. After the endodontic procedure, the cavities were restored with different post-core and overlay restorations (n = 12/group). Three groups (A1-A3) were restored with either conventional composite core (PFC; control) or flowable short-fiber-reinforced composite (SFRC) core with/without custom-made fiber posts and without overlays. Six groups had similar post-core foundations as described above but with either direct PFC (B1-B3) or indirect CAD/CAM (C1-C3) overlays. Fatigue survival was tested for all restorations using a cyclic loading machine until fracture occurred or 50,000 cycles were completed. Kaplan-Meyer survival analysis was conducted, followed by pairwise post hoc comparisons. RESULTS: None of the restored teeth survived all 50,000. Application of flowable SFRC as luting-core material with fiber post and CAD/CAD overlays (Group C3) showed superior performance regarding fatigue survival (p < 0.05) to all the other groups. Flowable SFRC with fiber post and direct overlay (Group B3) showed superior survival compared to all other direct techniques (p < 0.05), except for the same post-core foundation but without cuspal coverage (Group A3). CONCLUSIONS: Custom-made fiber post and SFRC as post luting core material with or without cuspal coverage performed well in terms of fatigue resistance and survival when used for the restoration of ET premolars. CLINICAL RELEVANCE: The fatigue survival of direct and indirect cuspal coverage restorations in ET MOD premolars is highly dependent on whether the core build-up is fiber-reinforced or not. The combination of short and long fibers in the form of individualized post-cores seems to offer a favorable solution in this situation.

Structural integrity of extracted teeth restored using three different post-and-core systems: An in vitro comparative study.

AIM: The objective of the study was to assess the in vitro fracture resistance of endodontically treated teeth restored using different post-and-core materials. MATERIALS AND METHODS: Extracted human mandibular premolars (n = 36) were extracted teeth and equally distributed into four (4) treatment groups: cast metal post-and-core, milled zirconia post-and-core, pre-fabricated post with composite resin core and control group. These samples were then each subjected to the load to fracture test using a universal testing machine. Fracture resistance data were compared among groups by analysis of variance and Fisher's exact test. RESULTS: The highest mean fracture resistance value was observed in the zirconia post-and-core treatment group (1567.26 ± 317.66 N), followed by the cast metal (1355.92 ± 621.56 N) and lastly the pre-fabricated post with composite resin core (725.67 ± 251.05 N) treatment group. Differences among groups were not statistically significantly different (P = 3.77). CONCLUSION: Endodontically treated mandibular premolars with a zirconia post-and-core system exhibited the highest robustness against structural failure based on its mean fracture resistance value. In addition, extracted teeth restored with cast post-and-core resisted a greater stress load than those restored with fiber-reinforced posts. Zirconia showed a more favorable fracture mode than the other restorations.

Evaluation of two CAD/CAM materials for Nayyar core and post-retained restorations: Three dimensional stress analysis.

OBJECTIVES: The aim of this study is to assess the stress distribution of a nanoceramic resin CAD/CAM material, Lava Ultimate (LU) and a polymer-infiltrated hybrid ceramic CAD/CAM material, Vita Enamic (VE) for enamel replacement for Nayyar core (corono-radicular dowel and core) or post-retained restoration designs of a maxillary first premolar tooth with missing palatal cusp. MATERIALS AND METHODS: A three dimensional finite element (FE) modelof maxillary first premolar with two roots was modeled. A mesial-occlusal-distal-palatal (MODP) cavity was designed with cavity floor above cemento-enamel junction and including buccal cuspal reduction. Restoration designs consisted of Nayyar core restoration (NCR) and post-retained restoration (PRR) with a glass fiber post. Vita Enamic (VE), Lava Ultimate (LU) were used for enamel and everX Posterior was used for dentin replacement. Vertical occlusal load (100 N) was applied on a spherical solid rigid material simulating the food stuff. Von Mises (VM) and maximum principle stress values were evaluated separately for the remaining enamel, remaining dentin and restorative material in megapascal (MPa). RESULTS: The analysis of both VM and maximum principle stress values revealed that the most intense stress accumulation was in the cervical region of enamel for both designs. For VM, similar stress values were observed only in dentin. Stress analysis of restorative materials showed that everX Posterior had the highest stress accumulation. CONCLUSIONS: The comparison of the two techniques showed that PRR had better stress distribution than NCR. NCR or PRR with LU or VE exhibited similar VM stress accumulation in dentin. Maximum principle stress analyses showed that PRR with LU transmitted the least stress to enamel and dentin indicating that when LU is the material of choice, post-retained restoration would be a satisfactory design. VM stress values of enamel revealed that VE absorbed the stress in itself and transferred less stress to dentin. This could point out that for the restoration of maxillary first premolar tooth with missing palatal cusp, VE may be a suitable material for NCR and PRR restoration techniques. HIGHLIGHTS: When fiber reinforced composite is used as dentin replacement in combination with VE as enamel replacement; any technique; PRR or NCR, may be preferred in the restoration of MODP cavities of endodontically treated maxillary premolars. The clinical relevance has to be further studied in-vivo.

Flexural strength of fiber reinforced posts after mechanical aging by simulated chewing forces.

This study evaluated the effect of simulated chewing forces on the flexural strength of fiber reinforced posts (FRPs). Four different brands of FRPs were selected as main group for the study: RelyX Fiber Post (RX), IceLight (ICE), Unicore Posts (UC), FlouroPost (FP). Ten posts in each main group didn't receive any aging process and tested as baseline (BL), other ten posts were subjected to simulated chewing forces/mechanical aging (MA) as follows: Post spaces were prepared in acrylic with drill. Depth of preparation was adjusted to leave 4-mm coronal part of posts protruding from canals. Coronal parts were incrementally restored with resin-composite (Clearfil Majesty Posterior A2, Kuraray, Osaka, Japan). Prepared samples were subjected to chewing cycles in a chewing simulator (Chewing Simulator CS-4, Mechatronik, Germany). Flexural strengths of all groups were measured with three-point bending test. Data were analyzed by two-way ANOVA and Tukey's test (α = 0.05). After MA, flexural strengths of all posts were significantly decreased when compared with BL for all FRPs tested (p < 0.05). At BL, highest flexural strength values were obtained for ICE. After MA, similar to BL, highest flexural strength values were obtained for ICE. Only RX showed statistically significant difference when compared with ICE (p < 0.05). UC and FP showed similar flexural strength values with ICE (p > 0.05). It may be concluded that chewing forces on post-core systems may reduce the flexural strengths of FRPs.

Spectrophotometric Evaluation of Crown Fragment a Year After Reattachment Using Fiber-Reinforced Post: A Case Report.

BACKGROUND: Crown fracture is the most common type of fracture and frequently affects the anterior teeth. Crown fractures have been treated in several ways depending on the location and kind of fracture. This case emphasizes reattachment of fractured fragments using fiber-reinforced post. Also this case report underlines the related aesthetic concerns of reattaching of the fractured fragment. CASE REPORT: Intraorally, examination revealed a complicated crown-root fracture of the left maxillary central (#21) and lateral incisor (#22). Moreover, the incisal one-third of the right maxillary central incisor (#11) was fractured. Baseline color of the tooth was recorded with a spectrophotometer to compare final color of tooth treated with fiber post. The root canal of 21 and 22 was filled with a sealer and gutta-percha. Then, the fiber-reinforced post was placed into the canals, and fractured segments were bonded with self-adhesive resin cement. Direct composite resin restoration was applied to 11. A year later, a second color measurement was recorded, and color differences (ΔE) were calculated. RESULT: In 12 months' follow-up, 11, 21 and 22 were asymptomatic with satisfying aesthetics, maxillar right incisor was vital. When crown discoloration was examined, there was clinically perceptible but acceptable discoloration without periapical pathology. CONCLUSION: Fiber reinforced post empowers not only the protection and reinforcement of tooth structure but also provides esthetic restoration.

Clinical evaluation of retention strength of two different adhesive systems on glass fiber-reinforced posts / 口腔疾病防治

Objective@# To evaluate the clinical effect of two different resin cements on the glass fiber-reinforced posts.@*Methods @# One hundred and thirty-six teeth were randomly divided into two groups, with sixty-eight in each. Group A used Multilink N self-etch system and group B used RelyX Unicem self-adhesive system to bond fiber posts. Follow-up examinations took place at 6, 12 and 24 months after the placement. @*Results @#The success ratios of two groups were all 97% above and there was no significant difference between two groups (P > 0.05). @*Conclusion@#Multilink N self-etch system and RelyX Unicem self-adhesive system all have good effect on glass fiber-reinforced posts bonding.

Comparison of the effect of shear bond strength with silane and other three chemical presurface treatments of a glass fiber-reinforced post on adhesion with a resin-based luting agent: An in vitro study.

BACKGROUND: Loss of retention has been cited to be the most common cause of the failure of postretained restoration with irreversible consequences when materials with different compositions are in intimate contact at the post/adhesive interface. With this background, a study was conducted to improve the adhesion at the resin phase of fiber posts using silane and other chemical pretreatments. MATERIALS AND METHODS: Hundred glass fiber-reinforced posts were tested with 4 different protocols (n = 25) using silane as a control (Group A) and other three experimental groups, namely, Group B-20% potassium permanganate, Group C-4% hydrofluoric acid, and Group D-10% hydrogen peroxide were pretreated on the postsurface followed by silanization. These specimens were bonded with dual-polymerizing resin-based luting agent, which were then loaded at the crosshead speed of 1 mm/min to record the shear bond strength at the post/adhesive interface. The data were analyzed using one-way ANOVA test for multiple group comparisons and the post hoc Bonferroni test for pairwise comparisons (P < 0.05). RESULTS: Group B showed more influence on the shear bond strength when compared to other protocols, respectively (P < 0.001). CONCLUSION: Alone silanization as a surface treatment did not improve the bond strength. Combination of chemical presurface treatments followed by silanization significantly enhanced the bond strength at the post/adhesive interface.

Development of new radiopaque glass fiber posts.

The aim of this study was to analyze the radiopacity and filler content of three experimental glass fiber posts (EGFP) in comparison with other glass/carbon fibers and metal posts from the dental market. Three EGFP were obtained by pultrusion of glass fibers in a polymer matrix based on 2,2-bis[4-(2-hydroxy-3-methacryloyloxypropoxy)-phenyl]propane (bis-GMA) and triethyleneglycol dimethacrylate (TEGDMA) monomers. Using intraoral sensor disks 27 posts, as well as mesiodistal sections of human molar and aluminum step wedges were radiographed for evaluation of radiopacity. The percentage compositions of fillers by weight and volume were investigated by combustion analysis. Two EGFP showed radiopacity higher than enamel. The commercial endodontic posts showed radiopacity as follows: higher than enamel, between enamel and dentin, and lower than dentin. The results showed statistically significant differences (p b 0.05)when evaluatedwith one-way ANOVA statistical analysis. According to combustion analyses, the filler content of the tested posts ranges between 58.84wt.% and 86.02wt.%. The filler content of the tested EGFP ranged between 68.91 wt.% and 79.04 wt.%. EGFP could be an alternative to commercial glass fiber posts. Futureglass fiber posts are recommended to present higher radiopacity than dentin and perhaps ideally similar to or higher than that of enamel, for improved clinical detection. The posts with a lower radiopacity than dentin should be considered insufficiently radiopaque. The radiopacity of some glass fiber posts is not greatly influenced by the amount of filler.

Effect of different adhesive systems and post surface treatments on the push-out bond strengths of fiber-reinforced post / 대한치과보철학회지

PURPOSE: The purpose of this study was to evaluate the push-out bond strength of glass-fiber post cemented with different adhesive systems and surface treatments. MATERIALS AND METHODS: 160 tooth samples made from 48 human maxillary single-rooted teeth with similar root length were divided into 4 groups according to the adhesive system (no adhesive, Adper Single Bond 2, Clearfil SE Bond, Clearfil S3). Each group had 4 subgroups according to the post surface treatment methods (no treatment, sandblast, silane, sandblast and silane). Posts (Parapost Fiber White) were cemented with Rely X Unicem. The teeth were sectioned perpendicular to their long axis into 1-mm thick sections. The push-out tests was performed at a speed of 0.5 mm/min. The results were evaluated by 2-way ANOVA, 1-way ANOVA and multiple comparison procedures (Tukey test) (α=0.05). RESULTS: Tukey test showed that the adhesive system significantly influenced the push-out strength. The Clearfil SE Bond group showed the highest value. Post surface treatments showed no significant effect. CONCLUSION: Bond strength of glass-fiber post cemented with self-adhesive resin cement using Clearfil SE Bond showed significantly higher values compared to other adhesive systems.

Fracture resistance of permanent anterior incisors using fiber-reinforced composite posts.

This in vitro study investigated whether permanent anterior incisors that are endodontically treated with cemented fiber-reinforced composite (FRC) posts without additional canal preparation can potentially increase the resistance to fracture and thus reduce the rate of clinical failure in root canals. Extracted human permanent maxillary central incisors (n = 120) were randomly assigned to 2 experimental groups (n = 60): thermocycled (Group 1) and non-thermocycled (Group 2). These 2 groups were then further divided into 3 subgroups (n = 20). Subgroup 1.1 specimens had root canals prepared and obturated with FRC posts placed. Subgroup 1.2 specimens were prepared and obturated, but did not receive posts. Subgroup 1.3 specimens did not receive root canal preparation, and served as a control. The same processes were repeated for Subgroups 2.1, 2.2, and 2.3, respectively. Significant differences were found between the thermocycled and the non-thermocycled subgroups. Subgroup comparison within the thermocycled group (Group 1) showed significantly higher fracture resistance values for the teeth with post cementation (P < .0001).

In vitro study of microleakage of endodontically treated teeth restored with different adhesive systems and fiber-reinforced posts / 대한치과보철학회지

PURPOSE: While studies have examined microleakage in endodontically treated teeth restored with posts, microleakage among post and adhesive systems remains a concern. This study compared the sealing properties of 3 adhesively luted post systems. MATERIALS AND METHODS: Thirty-six endodontically treated permanent maxillary central incisors were divided into 3 groups: Zirconia-glass fiber, Quartz-glass fiber, Polyethylene fiber posts. Post space was prepared and each post was adhesively luted with 3 systems. The specimens were separately immersed in freshly prepared 2% methylene blue solution for 1 week. The cleaned specimens were then embedded in autopolymerizing acrylic resin. The root portion of tooth were horizontally sectioned into three pieces (apical, middle, and coronal portions). An occlusal view of each section was digitally photographed with a stereomicroscope. The methylene blue-infiltrated surface for each specimen was measured. Dye penetration was estimated as the ratio of the methylene blue-infiltrated surface to the total dentin surface. RESULTS: No significant differences were found among post types. The variables of middle section and 3-stage adhesive produced significant differences in microleakage between the following post pairs: zirconia-glass fiber versus quartz-glass fiber, zirconia-glass fiber versus polyethylene fiber, and quartz-glass fiber versus polyethylene fiber (P<.05). There were significant differences between the apical and coronal sections of each post type, and between apical versus middle sections of quarze-glass fiber and polyethylene fiber posts (P<.05). CONCLUSION: No significant differences were found among post types. The 3-stage adhesive produced significant differences in microleakage between the following post pairs.

Crown reattachment with complicated chisel-type fracture using fiber-reinforced post.

INTRODUCTION: Maxillary incisors and specifically their crowns are the most common teeth involved in dental trauma because of their exposed position in the dental arch. Traumatized anterior teeth require quick functional and esthetic repair. In the case of a complex crown fracture, with the necessity of endodontic treatment, fiber-reinforced posts (FRC) were used to create a central support stump to restore the dental morphology. CASE REPORT: A 24-year-old male patient came to the dental clinic with dental injury to the maxillary left central incisor with a chisel-type fracture that extended subgingivally with a widely open pulp chamber. The patient reported a sports injury had occurred 1 day before. Provisional reposition of the crown was completed using a composite splint and after that endodontic treatment has been performed. Two days later, a fiber-reinforced composite resin post was placed into the canal and adhesive reattachment of the fragment also completed. The tooth was prepared for a composite resin veneer in the gingival third of the vestibular surface because of a visible fracture line. CONCLUSIONS: The combined use of a fiber-reinforced composite resin post and the original crown fragment is a simple and efficient procedure for the treatment of traumatized anterior teeth that appears to offer pleasing esthetic and functional results that is less invasive than conventional prosthodontic treatment.

Influence of modification in core building procedure on fracture strength and failure patterns of premolars restored with fiber post and composite core.

PURPOSE: The influence of the modified process in the fiber-reinforced post and resin core foundation treatment on the fracture resistance and failure pattern of premolar was tested in this study. MATERIALS AND METHODS: Thirty-six human mandibular premolars were divided into 4 groups (n = 9). In group DCT, the quartz fibre post (D.T. Light-post) was cemented with resin cement (DUO-LINK) and a core foundation was formed with composite resin (LIGHT-CORE). In group DMO and DMT, resin cement (DUO-LINK) was used for post (D.T. Light-post) cementation and core foundation; in group DMO, these procedures were performed simultaneously in one step, while DMT group was accomplished in separated two steps. In group LCT, the glass fiber post (LuxaPost) cementation and core foundation was accomplished with composite resin (LuxaCore-Dual) in separated procedures. Tooth were prepared with 2 mm ferrule and restored with nickel-chromium crowns. A static loading test was carried out and loads were applied to the buccal surface of the buccal cusp at a 45 degree inclination to the long axis of the tooth until failure occurred. The data were analyzed with MANOVA (α = .05). The failure pattern was observed and classified as either favorable (allowing repair) or unfavorable (not allowing repair). RESULTS: The mean fracture strength was highest in group DCT followed in descending order by groups DMO, DMT, and LCT. However, there were no significant differences in fracture strength between the groups. A higher prevalence of favorable fractures was detected in group DMT but there were no significant differences between the groups. CONCLUSION: The change of post or core foundation method does not appear to influence the fracture strength and failure patterns.

Bond strength between fiber posts and composite resin core: influence of temperature on silane coupling agents

This study evaluated the effect of air drying temperature and different silane coupling agents on the bond strength between glass fiber posts and composite resin core. The post surface was cleaned with alcohol and treated with different silane coupling agents, being three prehydrolyzed silanes [Silano (Angelus), Prosil (FGM), RelyX Ceramic Primer (3M ESPE)] and one two-component silane [Silane Coupling Agent (Dentsply)]. Two post-silanization air drying temperatures, 23ºC and 60ºC, were applied. A cylindrical plastic matrix was placed around the silanized post and filled with composite resin. Each bonded post provided 7 slices for push-out testing. Each slice was loaded to failure under compression at a cross-head speed of 0.5 mm/min. Data were analyzed by two-way ANOVA and Scott-Knott tests (α=0.05). Dunnett's test was used to compare the mean of the control group with that of each experimental group. Scanning electron microscopy (SEM) was used to evaluate the interface of the fractured slices. For the 23ºC air drying temperature, the use of RelyX Ceramic Primer resulted in significantly lower bond strength than the other silane coupling agents, while the bond strength with Silane Coupling Agent was the highest of all groups. Only with Silane Coupling Agent, the bond strength for the 23ºC air drying temperature was significantly higher than that for 60ºC air drying. In conclusion, the use of warm air drying after silane application produced no increase in the bond strength between the fiber-reinforced composite post and the composite core. The two-component silane produced higher bond strength than all prehydrolyzed silanes when it was used with air drying at room temperature.

Este estudo avaliou o efeito da temperatura do ar e diferentes silanos na resistência de união entre pino de fibra e resina composta. Os pinos foram limpos com álcool e tratados com diferentes silanos: três pré-hidrolizados [Silano (Angelus), Prosil (FGM), RelyX Ceramic Primer (3M ESPE)] e um de dois componentes [Silane Coupling Agent (Dentsply)]. Duas temperaturas (23ºC e 60ºC) para secagem do silano foram aplicadas. Matriz plástica cilíndrica foi posicionada em torno do pino já silanizado, e preenchida com resina composta simulando núcleo de preenchimento. Cada cilindro obtido pela união pino/preenchimento foi seccionado, gerando 7 fatias para ensaio mecânico de push-out. Aplicou-se sobre cada fatia carregamento de compressão, com velocidade de 0,5 mm/min, até a falha da amostra. Os dados foram analisados pela ANOVA e teste Scott-Knott (α=0,05). Utilizou-se teste de Dunnett para comparação do grupo controle com cada um dos outros grupos experimentais. Após ensaio mecânico, observaram-se as amostras em microscópio eletrônico de varredura. Para 23ºC, RelyX Ceramic Primer apresentou os menores valores de resistência de união, enquanto o Silane Coupling Agent (Dentsply) obteve os maiores valores. Para o Silane Coupling Agent (Dentsply), os valores de resistência de união foram maiores para temperatura de 23ºC do que 60ºC. Em conclusão, o uso de ar quente após aplicação do silano não gerou aumento nos valores de resistência de união entre pino de fibra e material de preenchimento de resina composta. O silano de dois componentes apresentou maior resistência de união do que todos os silanos pré-hidrolizados quando usados na temperatura ambiente.

Influence of modification in core building procedure on fracture strength and failure patterns of premolars restored with fiber post and composite core

PURPOSE: The influence of the modified process in the fiber-reinforced post and resin core foundation treatment on the fracture resistance and failure pattern of premolar was tested in this study. MATERIALS AND METHODS: Thirty-six human mandibular premolars were divided into 4 groups (n = 9). In group DCT, the quartz fibre post (D.T. Light-post) was cemented with resin cement (DUO-LINK) and a core foundation was formed with composite resin (LIGHT-CORE). In group DMO and DMT, resin cement (DUO-LINK) was used for post (D.T. Light-post) cementation and core foundation; in group DMO, these procedures were performed simultaneously in one step, while DMT group was accomplished in separated two steps. In group LCT, the glass fiber post (LuxaPost) cementation and core foundation was accomplished with composite resin (LuxaCore-Dual) in separated procedures. Tooth were prepared with 2 mm ferrule and restored with nickel-chromium crowns. A static loading test was carried out and loads were applied to the buccal surface of the buccal cusp at a 45 degree inclination to the long axis of the tooth until failure occurred. The data were analyzed with MANOVA (alpha = .05). The failure pattern was observed and classified as either favorable (allowing repair) or unfavorable (not allowing repair). RESULTS: The mean fracture strength was highest in group DCT followed in descending order by groups DMO, DMT, and LCT. However, there were no significant differences in fracture strength between the groups. A higher prevalence of favorable fractures was detected in group DMT but there were no significant differences between the groups. CONCLUSION: The change of post or core foundation method does not appear to influence the fracture strength and failure patterns.

Influence of modification in core building procedure on fracture strength and failure patterns of premolars restored with fiber post and composite core

PURPOSE: The influence of the modified process in the fiber-reinforced post and resin core foundation treatment on the fracture resistance and failure pattern of premolar was tested in this study. MATERIALS AND METHODS: Thirty-six human mandibular premolars were divided into 4 groups (n = 9). In group DCT, the quartz fibre post (D.T. Light-post) was cemented with resin cement (DUO-LINK) and a core foundation was formed with composite resin (LIGHT-CORE). In group DMO and DMT, resin cement (DUO-LINK) was used for post (D.T. Light-post) cementation and core foundation; in group DMO, these procedures were performed simultaneously in one step, while DMT group was accomplished in separated two steps. In group LCT, the glass fiber post (LuxaPost) cementation and core foundation was accomplished with composite resin (LuxaCore-Dual) in separated procedures. Tooth were prepared with 2 mm ferrule and restored with nickel-chromium crowns. A static loading test was carried out and loads were applied to the buccal surface of the buccal cusp at a 45 degree inclination to the long axis of the tooth until failure occurred. The data were analyzed with MANOVA (alpha = .05). The failure pattern was observed and classified as either favorable (allowing repair) or unfavorable (not allowing repair). RESULTS: The mean fracture strength was highest in group DCT followed in descending order by groups DMO, DMT, and LCT. However, there were no significant differences in fracture strength between the groups. A higher prevalence of favorable fractures was detected in group DMT but there were no significant differences between the groups. CONCLUSION: The change of post or core foundation method does not appear to influence the fracture strength and failure patterns.

Clinical evaluation of carbon fiber reinforced carbon endodontic post, glass fiber reinforced post with cast post and core: A one year comparative clinical study.

AIM: Restoring endodontically treated teeth is one of the major treatments provided by the dental practitioner. Selection and proper use of restorative materials continues to be a source of frustration for many clinicians. There is controversy surrounding the most suitable choice of restorative material and the placement method that will result in the highest probability of successful treatment. This clinical study compares two different varieties of fiber posts and one cast post and core in terms of mobility of crown margin under finger pressure, recurrent caries detected at the crown margin, fracture of the restoration, fracture of the root and periapical and periodontal pathology requiring crown removal over the period of 12months as evaluated by clinical and radiographical examination. MATERIALS AND METHODS: 30 root canal treated, single rooted maxillary anterior teeth of 25 patients in the age range of 18-60 years where a post retained crown was indicated were selected for the study between January 2007 and August 2007; and prepared in a standard clinical manner. It was divided into 3 groups of 10 teeth in each group. After post space preparation, the Carbon fiber and Glass fiber reinforced posts were cemented with Scotch bond multipurpose plus bonding agent and RelyX adhesive resin cement in the first and second groups respectively. The Cast post and cores were cemented with Zinc Phosphate cement in the third group. Following post- cementation, the preparation was further refined and a rubber base impression was taken for metal-ceramic crowns which was cemented with Zinc Phosphate cement. A baseline periapical radiograph was taken once each crown was cemented. All patients were evaluated after one week (baseline), 3 months, 6 months and one year for following characteristics mobility of crown margin under finger pressure, recurrent caries detected at the crown margin, fracture of the restoration, fracture of the root and periapical and periodontal pathology. RESULTS: Results after 12 months showed that none of the restorations among groups of cast post and core, carbon fiber reinforced post and glass fiber reinforced post with composite core restorations failed in terms of recurrent caries detected at the crown margin, fracture of the restoration, fracture of the root and periapical and periodontal pathology. One case of cast post and core and one case of carbon fiber reinforced post with composite core restorations showed slight mobility of crown margin under finger pressure at 12(th) month recall but all the cases of glass fiber post with composite core restorations did not show any signs of mobility of crown margin under finger pressure at all the recall periods on clinical and radiographical examination. CONCLUSION: From this 12 months clinical evaluation of all the cases in the 3 groups comprising of cast post and core; carbon fiber reinforced post with composite core and glass fiber reinforced post with composite core restored with porcelain fused to metal crowns, it is concluded that glass fiber reinforced post with composite core when used in single rooted upper anterior teeth are associated with a higher success rate in restoration of endodontically treated teeth.

Reattachment of coronal fragment using fiber-reinforced post: a case report.

Coronal fractures of permanent dentition are the most frequent type of dental injury. If the original tooth fragment is retained following fracture, the natural tooth structures can be reattached using adhesive protocols. The development and use of fiber-reinforced composite root canal posts make possible of the reattachment of the crown esthetically. This case report presents a clinical technique to reattachment maxillary lateral incisor tooth after trauma using direct fiber-reinforced post systems. At the 1-year follow-up, a slightly marginal discoloration, but no recurrent decay or composite clefts were detected and the resultant appearance was acceptable to the patient.

An evaluation of glass fiber-reinforced composite resin post core for severe defect restoration of front teeth / 实用口腔医学杂志

In order to explore the clinical effect of the glass fiber-reinforced composite resin post core for severe defect restoration of front teeth,sixty-two teeth were restored for forty-one patients with severe defect restoration of front teeth by glass fiber-reinforced composite resin post core plus alumina all-ceramic crown.Through 0.6-2.0 years follow up,all the prosthesis worked very well without breaking or falling off,no gum coloring except two posts fell off after the restoration at sixth month.The patients satisfied with the restoration.