Minimally Invasive Esthetic Reinforcement of a Fractured Anterior Tooth Using Dentapreg PINPost: A Case Report.

The reason to use post is to retain the core that holds the definitive prosthesis. The maxillary central incisor always poses a challenge during reconstruction using the post and core system. Dentapreg PINPost, a pre-cured flexible post made of fiber-reinforced composite (FRC), has many advantages over metallic posts and fiber posts. The purpose of this case report is to present an innovative technique to place both FRC posts and FRC sheets as a single assembly into the canal which gives a monoblock effect. This technique is feasible and may eradicate some of the problems associated with the failure of the post and core.

Construction of metal endocrown for a short clinical second molar crown.

This case highlights where a metal endocrown was used as a novel technique. The metal endocrown showed promising outcomes during the 5-year follow-up, utilizing a resin base to preserve tissue and act as a stress breaker. This approach was used to preserve the tooth and avoid extraction or periodontal surgery.

Clinical performance of computer-aided design/computer-aided manufacture lithium disilicate ceramic endocrown restorations: A 2-year study.

Context: Optimal restoration methods for endodontically treated teeth (ETTs) have always remained an ongoing discussion among physicians in this day and age. ETTs have a tendency to fracture when chewing, compared to initial teeth. From the perspective of biology, preserving and restoring tooth structure is critical to maintaining biomechanical, functional, and esthetic harmony. Dental bonding techniques have lessened the necessity for post-and-core restorations in ETTs with severe substance loss. A minimally invasive endodontic restoration technique called "endocrown" was initially introduced by Bindl and Mörmann in 1999. Aims: The aim of the study was to clinically evaluate all-ceramic mandibular molar endocrowns made using computer-aided design/computer-aided manufacturing (CAD/CAM) following 2 years of follow-up. Subjects and Methods: This unblinded study contains 56 patients with 56 mandibular molars, which had severe substance loss. After teeth preparation, lithium disilicate ceramic endocrowns were manufactured with the CEREC CAD/CAM system, and cementation was performed using a composite luting agent. The endocrowns were assessed using the modified United States Public Health Service criteria at baseline, 6 months, 1 year, and 2 years following placement. Patient satisfaction was evaluated using a questionnaire. Statistical Analysis Used: This study used descriptive statistics, including mean, standard deviation, and 95% confidence intervals. Data were processed using STATA version 14.0 (StataCorp LLC, USA). Results: Two endocrowns (3.6%) failed throughout the period of observation. The high clinical rating criteria (96.4%, count of 54) and the increased satisfaction percentage (94.6%, count of 53) remained practically stable during the follow-up assessments at 6 months and after 1-2 years. Conclusions: Endocrown offers a less invasive treatment option that may be a better method for endodontically treated mandibular molars. With contemporary CAD/CAM technology and new materials, time in the chair and esthetics optimally improved, bringing satisfaction to the patient.

Mechanical behavior of endodontically treated teeth: A three-dimensional finite element analysis using displacement vector.

PURPOSE: This study aimed to analyze the effects of core materials, remaining tooth structures, and interfacial bonding on stress distribution in endodontically treated teeth using finite element analysis (FEA). MATERIALS AND METHODS: Three-dimensional FEA was conducted using a reverse engineering technique based on maxillary premolars scanned by micro-computed tomography. Six models were generated with or without ferrules and with one of the following three abutment systems: metal core, resin core, or resin core with fiber posts. In each model, bonding and debonding were assumed in the dentin and surrounding structures: bonded and debonded models. The maximum principal stress values were recorded, and stress distribution of the entire restored teeth and dentin was generated. Furthermore, the distribution of the displacement vector of the debonded models was generated. RESULTS: In comparing the bonded and debonded models, the debonded models showed larger values for tensile stresses than those in bonded models for all abutment models. The models without ferrules rotated around the center of the abutment, whereas those with ferrules did not show remarkable displacement in the analysis. CONCLUSION: FEA assuming fracture of adhesive interface proved to be an effective method to clarify the significance of ferrules. It prevents stress concentration in dentin by reducing the rotation of the abutment, even when the adhesive fails.

Survey regarding the use of endodontic posts among dentists of twin cities, Rawalpindi and Islamabad, Pakistan.

The purpose of the study was to assess the knowledge, attitude, and practices of dentists of twin cities regarding the use of endodontic posts in root canal treated tooth. A questionnaire was created and distributed among dentists of Rawalpindi and Islamabad via social media platforms regarding the use of posts. The results revealed that majority (60%) of the participants used endodontic posts for teeth with adequate ferrule, and believed that the function of endodontic posts is to retain the core material (50.5%). Glass fibre posts were preferred for anterior teeth (87%), whereas metal posts were favoured in posterior teeth (63%). It was concluded that the main function of the endodontic post is to retain the core material. The commonest indication is when there is at least 2mm of ferrule present and the optimal post length is 2/3rd of the root canal.

Endocrowns: Indications, Preparation Techniques, and Material Selection.

Endodontic treatment is often necessary in the field of dentistry. As the tooth structure is lost during such treatment, the tooth may become weaker and lose some of its mechanical qualities. Endodontically treated posterior teeth require cuspal coverage because of their anatomical features. Endocrowns are regarded as a suitable choice for restoring teeth that have undergone endodontic treatment. These restorations are recommended when there is a substantial loss of tooth structure, restricted interocclusal space, or a short clinical crown. They are also contraindicated in case of severe loss of tooth structure where adhesion is not applicable. Endocrowns require a specific preparation design that is distinct from the conventional crown. They can be manufactured by two methods: heat pressing or computer-aided design/computer-aided manufacturing (CAD/CAM). Moreover, several materials have been used in fabricating endocrown restoration. Lithium disilicate glass-ceramic is the most recommended material as it possesses excellent mechanical properties and esthetic results with the ability to bond to tooth structure. In conclusion, several kinds of literature recommend using them for molars. Further research is needed to evaluate this technique for premolar and anterior teeth.

Digitally Guided Direct Composite Injection Technique with a Bi-layer Clear Mini-Index for the Management of Extensive Occlusal Caries in a Pediatric Patient: A Case Report.

PURPOSE: This case report presents a direct composite inverse injection technique using a bi-layer clear mini-index fabricated with a digital workflow to restore extensive posterior occlusal cavities in a 13-year-old patient. MATERIALS AND METHODS: After a root canal treatment in the right mandibular first molar and step-wise excavation of deep caries in the left mandibular first molar, the extensive occlusal restorations were digitally designed using CAD software, upon which digital wax-ups were 3D-printed. Bi-layer clear mini-indices consisting of a hard outer plastic layer and an elastic inner silicone layer were prepared from the 3D-printed cast. The bonding surfaces were deproteinized using a 6% sodium hypochlorite solution, and an antioxidant (Clearfil DC Activator; Kuraray Noritake) was utilized to improve the dentin bonding durability of a 2-step self-etch adhesive (Clearfil SE Bond 2; Kuraray Noritake). Subsequently, a highly filled universal-shade flowable resin composite (RC) was incrementally placed into the cavities. To create the final occlusal morphology, the same RC was inversely injected through the opening of the bi-layer indices. RESULTS: The workflow was feasible, and the occlusal cavities were efficiently restored using the injection technique. Occlusal carving and adjustments of the morphology were not necessary, leading to less chair time. At the 1-year follow-up, the clinical outcome was excellent. CONCLUSION: The injection technique with a bi-layer clear mini-index accurately translated the digital wax-ups into large, final restorations. Precise morphology and shortened chair time enhanced patient satisfaction, but at the expense of multiple visits.

Effect of Dental Glass Fiber Posts on Root Stresses and Fracture Behavior of Endodontically Treated Maxillary Central Incisors: A Finite Element Analysis Study.

OBJECTIVE:  In this work, the influence of glass fiber posts with different designs on the root stress that had endodontic treatment was examined using the finite element method. METHOD:  Using two distinct materials (metal and glass fiber) and two different prototypes (tapered and parallel-sided), four three-dimensional (3D) finite element models of an upper central incisor were made and studied. Each 3D model received an oblique loading of 100 N. All forces were dispatched as distributed pressure to the aforementioned region. There were no considerations made for potential stresses when performing the endodontic procedure. The endodontic treatment was conducted without taking into account any potential stressors. The root stresses were then recorded. RESULTS: The largest tensile stress is often focused at the apical third of the post and post/cement contact, as well as at the coronal third of the root on both the labial and palatal sides of the root, independent of the post's design and material. Restoration of endodontically treated maxillary central incisors with glass fiber posts has been shown to have less stress concentration than titanium posts. Regardless of the post materials employed, the tapered post design generated a higher tensile stress distribution than the parallel side design. CONCLUSIONS:  Prefabricated fiber posts used in model restoration resulted in more evenly distributed stress and less concentrated stress on the root. Reduction in modulus of elasticity of post materials used generally shows less stress concentration.

Fracture strength and hybrid layer formation of endodontically-treated teeth after dental bleaching photoactivated with violet LED.

OBJECTIVE: To evaluate in vitro the effect of dental bleaching using high concentration hydrogen peroxide (HP) photoactivated with violet LED on fracture strength and hybrid layer formation. METHODS: forty endodontically-treated bovine teeth were randomized into four groups (n = 10): C - Control, HP - 35% hydrogen peroxide, HP-BL - 35% hydrogen peroxide photoactivated with blue LED, HP-VL - 35% hydrogen peroxide photoactivated with violet LED. Three bleaching sessions with an interval of 7 days between them were performed. After 10 days of the last bleaching session, the dental crowns were restored and submitted to the fracture strength test. Five specimens from each group were used to evaluate the hybrid layer formation by scanning electron microscope (SEM) images. One-way ANOVA and Kruskal-Wallis test were used for parametric and non-parametric data, respectively. Significance level of 5% was adopted to all the tests. RESULTS: No differences on fracture strength among the groups were observed (p > 0.05). HP and HP-BL showed alterations on hybrid layer formation compared to C group (p < 0.05), but not for HP-VL (p > 0.05). No differences on hybrid layer formation were observed among HP, HP-VL and HP-BL groups (p > 0.05). CONCLUSION: Dental bleaching, photoactivated or not, did not affect the fracture strength of endodontically-treated teeth. Regardless of the protocol used, hydrogen peroxide altered the hybrid layer formation at some level when the restoration was placed after 10 days of the last bleaching session.

Root-analogue implants compared to forced orthodontic extrusion: a retrospective analysis of clinical, radiological and esthetic outcomes after restoration.

OBJECTIVES: To assess clinical, radiological and esthetic outcomes of restorations supported by root-analogue implants (RAIs) or roots of severely damaged teeth after forced orthodontic extrusion (FOE). MATERIALS AND METHODS: Clinical data regarding milled one-piece (titanium/zirconia roots and zirconia abutments) RAIs (REPLICATE™ System) and FOE were recorded and retrospectively evaluated for 40 patients by two investigators. Strict inclusion and exclusion criteria were applied. Functional and esthetic outcomes were assessed for n = 20 pre-molars and n = 20 anterior teeth via comparison of radiographic and digital images applying the novel Functional Implant Prosthodontic Score (FIPS). Krippendorff's alpha coefficient was calculated to assess inter-rater reliability. Mann-Whitney-U-Test was used to compare the assessed parameters. Level of significance was set to p < 0.05. RESULTS: After a mean observation period of 18.4 ± 5.7 months for restorations supported by RAIs and 43.9 ± 16.4 months for restorations after FOE, mean FIPS scores were 9.2/8.8 ± 1.1/1.2 (RAIs) and 7.4/7.7 ± 1.3/1.5 (FOE), respectively. Krippendorff's alpha coefficients did not reveal unacceptable inter-rater reliabilities regarding the investigators and applicability of FIPS. Significant differences were documented when comparing restorations after FOE or supported by RAIs regarding bone loss (p < 0.01), presence of papillae (p < 0.05) and quality and quantity of mucosa (p < 0.02) in favor of FOE. CONCLUSIONS: Within the main limitations of sample size and the retrospective study design, both concepts seem to provide clinically acceptable results. CLINICAL RELEVANCE: Bone- and tissue-preserving characteristics regarding the concept of FOE are promising. It could be applicable for socket preservation and subsequent conventional implant placements in an adapted workflow.

Effect of apical root resection, orthodontic extrusion, and surgical crown lengthening on load capability.

OBJECTIVES: This study aims to investigate the load-to-fracture of procedures changing crown-to-root ratio (RCRR) aimed to restore severely damaged upper central incisors to avoid tooth extraction compared to implant placement. There is no evidence on load capability after apical root resection (AR), orthodontic extrusion (OE), and surgical crown lengthening (SCL) in respect to RCRR, respectively. MATERIAL AND METHODS: Human maxillary central incisors were endodontically treated, decoronated, and divided into 4 groups (n = 48). The following specimen preparation was performed: (I) adhesive core-and-post build-up (control), (II) as (I) and 2 mm apical root resection (AR), (III) before adhesive core-and-post build-up teeth were shortened 2 mm coronally (OE) (IV) as (I), but specimens were embedded 4 mm instead of 2 mm below the CEJ (SCL), group (V) implant-borne restoration with individual all-ceramic abutments (n = 12; ∅4.1/l = 12 mm) (IBR). All specimens received all-ceramic crowns, thermo-mechanical (TML), and subsequent linear loading (LL) until failure. RCRR were calculated and log-rank, Kruskal-Wallis, Mann-Whitney U, ANOVA, and chi-square tests applied (p = 0.05). RESULTS: Fracture loads after subsequent LL differed significantly (p = 0.001) between groups, while implants showed the highest values. Fmax median (min/max) were as follows: (I) 252 (204/542), (II) 293 (243/443), (III) 253 (183/371), (IV) 195 (140/274), and (V) 446 (370/539). Pair-wise comparison showed significant differences (p = 0.001) between group I/IV and group V, I, and IV (p = 0.045), II and IV (p = 0.001), and III compared to IV (p = 0.033), respectively. RCRR below 1 significantly increased load capability compared to RCRR = 1. CONCLUSIONS: OE appears to preferably ensure biomechanical stability of teeth that are endodontically treated and receive core-and-post and crown placement compared to SCL. AR has no adverse biomechanical impact. RCRR < 1 is biomechanically beneficial. CLINICAL RELEVANCE: For endodontically treated and restored teeth, orthodontic extrusion should be preferred compared to surgical crown lengthening prior single-crown restoration. As orthodontic extrusion, apical root resection has no adverse effect on load capability. Single-crown implant-borne restorations are most load capable.

Stress distribution of endodontically treated mandibular molars with varying amounts of tooth structure restored with direct composite resin with or without cuspal coverage: A 3D finite element analysis.

Background: Decision-making regarding whether cuspal coverage is required or not for the restoration of root canal-treated posterior teeth is still a matter of challenge for the dentist. Methodology: Four models of endodontically treated mandibular molars with mesio-occlusal (MO) cavity were designed and simulated with direct composite resin restorations. Group 1A - cavity width <½ the intercuspal distance restored without cuspal coverage, Group 1B - same as Group 1A but with cuspal coverage, Group 2A - MO cavity width >½ but <2/3rd the intercuspal distance restored without cuspal coverage, and Group 2B - same as Group 2A but with cuspal coverage. The models received occlusal load to simulate a mastication load. Static finite element analysis (FEA) was adopted for predicting the stress distribution generated in the restored tooth by the loading condition. Results: FEA of the models have shown that the variations in stress values were significant in bulk-fill material compared to enamel and other structures. Comparing the maximum and minimum principal stress values in the overall region demonstrated that 2A was safer, whereas 2B was found to be the worst case. Conclusions: The results indicate that restoration of endodontically treated mandibular molar with loss of one marginal ridge with composite resin without cuspal coverage revealed minimal internal stress values and showed the best performance overall.

Survival and success of composite resin restorations in endodontically treated maxillary incisors with minimal structure loss.

The primary aim of this study was to evaluate the clinical performance of nanofilled composite resin restorations in traumatized, endodontically treated maxillary incisors with structural loss of 40% or less. The performance of the restorations was assessed in terms of longevity (survival) and esthetics (success) over a 20-month period. The secondary objective was to employ a novel digital method to quantify preoperative tooth structure loss. Sixty-one fractured maxillary incisors in 55 patients were included in the study. The teeth were photographed with a digital single-lens reflex camera equipped with a macro ring flash. The amount of lost tooth structure was calculated with digital photography software. The teeth were restored with a nanohybrid composite resin and self-etching adhesive system bonding agent. To assess esthetics, color change in the blue-yellow axis (Δb*) of the composite resin restoration was evaluated digitally with the Commission Internationale de l'Eclairage (CIE) L*a*b color system. The Wilcoxon signed-rank test was used to assess Δb*, and a Kaplan-Meier survival analysis was used to assess the longevity of the restorations. The study findings showed a statistically significant difference between pretreatment and posttreatment b* values (P < 0.05), but the difference was too small to be clinically perceptible to the human eye. A total of 5 restorations (9.8%) failed. The remaining restorations survived for a mean (SD) period of 18.6 (4.4) months. The log-rank test did not show any significant association between the amount of residual tooth structure and success of the restoration. The results of this study showed that use of direct composite resin restorations in endodontically treated maxillary incisors resulted in acceptable survival and success rates. Trial registration: Clinical Trial Registry of India No. CTRI/2020/01/023019.

Effect of different indirect composite onlay and core materials on fracture resistance of endodontically treated maxillary premolars.

Purpose To compare and evaluate the effects of different indirect composite onlay and/or core buildup materials on the fracture resistance and fracture mode of restored endodontically treated premolars.Methods Two conventional handmade indirect composite resins (SR Nexco (NC) and Ceramage (CM)) and two core buildup materials, dual-cure composite resin (MultiCore Flow (MC)), and short fiber-reinforced composite resin (EverX Posterior (EXP)), were selected. Sixty maxillary premolars were randomly divided into six groups (n=10). Group 1 included intact teeth (INT; positive control). Mesio-occluso-distal cavity preparation and endodontic treatment was performed on the remaining premolars. Group 2 was restored with polymer-reinforced zinc oxide eugenol intermediate restorative material (IRM; negative control), whereas the experimental groups (groups 3-6) were restored with core buildup material and indirect composite onlay (MC_NC, MC_CM, EXP_NC, and EXP_CM). The specimens received compressive loading using a universal testing machine, at 45° to the long axis with a crosshead speed of 0.5 mm/min until fracture. Fracture modes were visually analyzed. Fracture resistance was measured and statistically analyzed using two-way and one-way ANOVA (α=0.05).Results Only the type of indirect composite onlay affected the fracture resistance of the experimental groups (P=0.009). The MC_CM group showed the highest fracture resistance, which was significantly higher than that of the MC_NC group (P=0.031). No statistically significant differences were found between the INT group and other experimental groups(P>0.05). All groups had a greater incidence of restorable than unrestorable failures.Conclusions The type of indirect composite onlay affected the fracture resistance of restored endodontically treated maxillary premolars.

Implant or Tooth?-A Prospective Clinical Study on Oral Health-Related Quality of Life for Patients with "Unrestorable" Teeth.

In cases of severely compromised teeth, dental practitioners are confronted with the therapeutic decision of whether to restore a tooth or replace it with an implant. Comparative scientific evidence on patient perception of both treatment approaches is scarce. The subject of this prospective clinical study was to compare oral health-related quality of life (OHRQoL) between two treatment groups: restoration of severely destroyed teeth after orthodontic extrusion (FOE) versus tooth extraction and implant-supported single crown restoration (ISC). A self-selected trial was performed with 21 patients per group. OHRQoL was assessed with the aid of the Oral Health Impact Profile (OHIP-G49) at different time intervals: before treatment (T1), after treatment (T2), after restoration (T3) and at recall (T4). Overall, OHIP scores improved from baseline to follow-up for both concepts with no significant differences between groups. There were no significant differences in subscales between FOE and ISC at T1, T3 and T4. In terms of functional limitations (p = 0.003) and physical disability (p = 0.021), patients in the FOE group temporarily exhibited lower OHRQoL at T2 in comparison to the ISC group. However, at baseline, after final restoration and at recall, the study demonstrates the same level of OHRQoL for both treatment concepts.

Comparative Evaluation of Two Different Fiber-Reinforced Composite Materials in Class 1 Post-Endodontic Restorations in Molars-A Randomized Clinical Study.

This study aimed to evaluate and compare two different fiber-reinforced composite materials in class I post-endodontic restoration in molars. A total of 50 patients were randomly assigned into two groups (n = 25 for each group); group A: everX Posterior (packable composite) with a top layer of solareX (nano-hybrid composite) and group B: everX Flow (flowable composite) with a top layer of G-aenial universal injectable (flowable composite). Patients were evaluated immediately after the procedure (baseline), at 6 months, and at 1 year time intervals based on the modified USPHS criteria. The statistical analysis using a chi-square test showed no statistically significant difference in the clinical performance of group A and group B. Clinical performance of the combination of everX Flow with overlying G-aenial universal injectable composite proved to be comparable with everX Posterior with overlying solareX composite as post-endodontic restorations in class I lesions in permanent molars.

Corono-radicular reinforcement with minimal invasion: A novel case report.

Maxillary premolar with an oval-shaped canal always poses a challenge while reconstruction using the post and core system. Fiber-post has many advantages over metallic-post and so fiber-post is becoming more popular and particularly widely used than metallic-post nowadays. Fiber-post has benefits of esthetic and strength, and its combination with flexible material, Ribbond has provided it with a high rise in the field of dentistry. The purpose of this case report was to show an innovative technique to place both glass fiber-post and Ribbond as a single assembly into the canal which gives a monoblock effect. This technique is feasible and may eradicate some of the problems associated with the cementation of ill-fitted fiber-post in an oval-shaped canal with widened canal space.

Fracture Resistance of Endodontically Restored Teeth with Two System Root Post

ABSTRACT: The objective of this study was to determinate the fracture resistance of endodontically treated teeth and restored with two root post systems: i) resin post, ii) fiber post. A total of 60 teeth were freshly extracted, endodontic ally treated and randomly divided in two groups (n= 30/each group) for standardized restoration; Group 1 (Group R): Resin post and resin restoration, Group 2 (Group FP): Fiberglass post and resin restoration. Both groups' samples were mounted in a metallic base at 135º to allow them to be stabilized and held in the universal testing machine by applying a vertical force at cross speed of 1mm/min. Data were recorded in Newtons (N) Previous to test the fracture resistance; all samples were stored in distilled water at 37 ºC for 24 hours. Data were subject to the Saphiro-Wilk test for normality distribution and Student's t test. Significance was considered at 0.05 values. The values of fiber post group showed normal distribution compared to the resin group, demonstrating less variability among the values. The group FP displayed higher fracture resistance (299.77±100 N) than group R (205.57±86.40 N), with significant differences (p= 0.00002). The greatest fracture resistance was recorded for the group having fiber post reinforced and composite cores. It is suggested that fiberglass post restoration is the first option when endodontic treatment requires core restoration.

RESUMEN: El objetivo del estudio fue determinar la resistencia a la fractura de dientes tratados endodónticamente y restaurados con dos sistemas de endopostes radiculares: I) poste de resina, II) poste de fibra. Un total de 60 dientes recién extraídos fueron tratados endodónticamente y divididos al azar en dos grupos (n= 30/ cada grupo) para la restauración estandarizada; Grupo 1 (Grupo R): Pilares de resina y restauración, Grupo 2 (Grupo FP): Pilares de fibra de vidrio y restauración de resina. Las muestras de ambos grupos se montaron en una base metálica a 135º para permitir su estabilización y sujeción en la máquina universal de ensayos aplicando una fuerza vertical a velocidad transversal de 1 mm/min. Los datos se registraron en Newtons (N), para probar la resistencia a la fractura; todas las muestras se almacenaron en agua destilada a 37 ºC durante 24 horas. Los datos se sometieron a la prueba de normalidad de Saphiro-Wilk y la pruebas t de Student. La significancia se consideró con un valor de 0,05. Los valores del grupo de postes de fibra mostraron una distribución normal en comparación con el grupo de resinas, demostrando menor variabilidad entre los valores. El grupo FP mostró mayor resistencia a la fractura (299,77±100 N) que el grupo R (205,57±86,40 N) que el grupo con diferencias significativas (p= 0,00002). La mayor resistencia a la fractura se registró para el grupo que tenía núcleos compuestos y reforzados con postes de fibra. Se sugiere que la restauración posterior de fibra de vidrio es la primera opción cuando el tratamiento de endodoncia requiere una restauración del núcleo.

Long-term Survival of Adhesively Luted Post-endodontic Restorations.

INTRODUCTION: The objective of this prospective clinical study was to investigate survival for endodontically treated teeth restored with adhesively luted prefabricated dentinlike or rigid posts. METHODS: Data were recorded for glass-fiber posts (GFPs) and compared with historical controls evaluating glass-fiber (GFP I) and titanium posts (TPs) for 128 patients. Three groups were defined based on the type of post system used: group 1, GFP I (n = 41); group 2, GFP II (n = 41); and group 3, TP (n = 46). Posts were adhesively luted with self-adhesive resin, adhesive composite core buildups were performed, and all teeth were restored with full-coverage restorations. The primary end point was restoration survival at recall. Outcome was assessed after 6, 12, 24 and up to 178 months clinically and radiographically. Data were analyzed by the Kaplan-Meier log-rank test and Cox regression analysis. RESULTS: After up to 178 months of observation, 26 restorations failed (GFP I: 10, GFP II: 9, and TP: 7) and 49 (GFP I: 18, GFP II: 12, and TP: 19) were in situ. Cumulative survival probabilities were 57.1% for the GFP I, 56.5% for the GFP II, and 71.8% for the TP groups. In bivariate Cox regression, the factors tooth type and grade of abrasion were significantly assfociated with failure. In multivariate Cox regression, none of the investigated factors were significantly associated with failure. The post system had no significant impact on tooth survival (P > .05). CONCLUSIONS: Comparing GFPs and TPs, the post system had no impact on tooth survival up to 15 years. This study indicates that the effect size of post material on survival is low.

Influence of one-wall remaining coronal tooth with resin abutment and fiber post on static and dynamic fracture resistance.

The objective of this study was to determine the influence of height and thickness of the one wall remaining coronal tooth structure on the fracture resistance of an endodontically treated root with resin abutment build-up using resin composite and fiber-reinforced resin composite post. Static and dynamic fracture tests were performed by placing the remaining tooth wall on the tensile side and applying loads at an angle of 30° from the tooth axis. Superior static fracture resistance was observed when the wall remaining on the tooth had a height and thickness greater than 1.0 mm. The dynamic fatigue test showed high loading capacity or fracture resistance in specimens with large height and thickness. The dynamic fatigue test showed the influence of the remaining tooth structure on fracture resistance clearly. In conclusion, the static and dynamic fracture resistances increased with the height and thickness of the one wall remaining tooth structure.