BACKGROUND: An optimum restoration for reconstructing endodontically treated teeth should provide excellent marginal adaptation, high fracture resistance as well as maximum tooth structure conservation. The purpose of this study was to evaluate the marginal adaptation and fatigue resistance of different coronal restorations in endodontically treated premolars.
METHODS: Thirty sound maxillary first premolars were endodontically treated and received MOD cavities. Teeth were randomly allocated into three groups (n = 10) according to the type of coronal restoration: Group R: polyethylene fibers (ribbond), fibers-reinforced composite (everX posterior) and final layer of nano-hybrid composite. Group O: indirect lithium disilicate overlay and Group C: fiber-post, resin composite restoration, and lithium disilicate crown. Marginal gap assessment was performed before and after thermocycling (5000 cycles) using stereomicroscope. Samples were subjected to stepwise-stress loading starting at 200 N, and increased by 100 N in each step until failure occurred. Statistical analysis was done by One-way ANOVA followed Tukey`s Post Hoc test for multiple comparison. Paired t test was used to compare the marginal adaptation before and after thermocycling. Survival probability was evaluated by Life table survival analysis. Failure mode analysis was performed with Chi-square test.
RESULTS: Marginal gap was significantly the lowest in group R (37.49 ± 5.05) and (42.68 ± 2.38), while being the highest in group C (59.78 ± 5.67) and (71.52 ± 5.18) in before and after thermocycling respectively (P < 0.0001). Fatigue resistance was the highest for group O (1310.8 ± 196.7), and the lowest for group R (905.4 ± 170.51) with a significant difference between groups (P < 0.0001). Crown group had the highest percentage (80%) of catastrophic failure, while, overlay group exhibited the lowest (20%).
CONCLUSIONS: Direct restoration without cuspal coverage using ribbon fibers with short FRC provided better marginal adaptation than indirect overlays and crowns, but fatigue resistance wasn\'t significantly improved. Adhesive ceramic overlays showed the best fatigue performance and the least catastrophic failure rate compared to both direct fiber-reinforced composite and indirect ceramic full coverage restorations.
CONCLUSIONS: Indirect adhesive overlays are a suitable, more conservative restorative option for endodontically treated teeth than full coverage restorations, especially when tooth structure is severely compromised.

BACKGROUND: Mesio-occluso-distal (MOD) cavity preparations are often fragile due to the amount of tooth and carious structure removed. MOD cavities can often fracture if left unsupported.
OBJECTIVE: The study investigated the maximum fracture load of mesi-occluso-distal cavities restored using direct composite resin restorations with various reinforcement techniques.
METHODS: Seventy-two freshly extracted, intact human posterior teeth were disinfected, checked, and prepared according to predetermined standards for mesio-occluso-distal cavity design (MOD). The teeth were assigned randomly into six groups. The first group was the control group restored conventionally with a nanohybrid composite resin (Group I). The other five groups were restored with a nanohybrid composite resin reinforced with different techniques: the ACTIVA BioACTIVE-Restorative and -Liner as a dentin substitute and layered with a nanohybrid composite (Group II); the everX Posterior composite resin layered with a nanohybrid composite (Group III); polyethylene fibers called \"Ribbond\" placed on both axial walls and the floor of the cavity, and layered with a nanohybrid composite (Group IV); polyethylene fibers placed on both axial walls and the floor of the cavity, and layered with the ACTIVA BioACTIVE-Restorative and -Liner as a dentin substitute and nanohybrid composite (Group V); and polyethylene fibers placed on both axial walls and the floor of the cavity and layered with the everX posterior composite resin and nanohybrid composite (Group VI). All teeth were subjected to thermocycling to simulate the oral environment. The maximum load was measured using a universal testing machine.
RESULTS: The highest maximum load was exhibited by Group III with the everX posterior composite resin, followed by Group IV, Group VI, Group I, Group II, and Group V. A statistically significant difference was demonstrated between groups (p = 0.0023). When adjusting for multiple comparisons, there were statistical differences specific to comparisons between Group III versus I, Group III versus II, Group IV versus II, and Group V versus III.
CONCLUSIONS: Within the limitations of the current study, it can be concluded that a higher maximum load resistance can be achieved (statistically significant) when reinforcing nanohybrid composite resin MOD restorations with everX Posterior.

This in vitro study aimed to compare the fracture strength of direct non-reinforced class II composite resin restorations and polyethylene fiber-reinforced restorations, and also to investigate the influence of the locations of polyethylene fibers within the cavity on the fracture strength. Sixty freshly extracted human teeth were disinfected and prepared (class II cavity design). The teeth were assigned randomly into four groups (n = 13). Group I (control) was restored with nano-hybrid composite resin. The other three experimental groups were restored with the same composite resin material reinforced by polyethylene fibers (Ribbond) at different locations. Fibers were placed either on the axial wall (Group II), on the gingival floor (Group III), or on the axial wall and pulpal/gingival floor (Group IV) of the proximal cavity. All the teeth were subjected to thermocycling to simulate the oral environment. The fracture strength was measured using a universal testing machine. Group IV had the highest mean fracture strength at maximum load (148.74 MPa), followed by Group II (140.73 MPa), Group III (136.34 MPa), and Group I (130.08 MPa), with a statistically significant difference from the control group (p = 0.008) but not between groups II and III.

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.

OBJECTIVE: This study aims to compare the resistance to fracture in maxillary incisors which were fractured in two different oblique patterns and then were re-attached and reinforced using anatomic fiber-reinforced composite (FRC) post.
METHODS: Sixty extracted and intact human maxillary incisors were obtained and divided into two groups (A and B; n = 30). \"Labiopalatal\" and \"palatolabial\" fractures were induced in group A and group B, respectively. These two groups were further subdivided into two subgroups (n = 15). In subgroup I Ribbond fiber (Ribbond Inc., Seattle, WA, USA) and in subgroup II Everstick post (everStick Post™, GC Corporation, Tokyo, Japan) were used. Fractured fragments were re-attached using resin and tested for fracture resistance in universal testing machine. Statistical analysis was done with ANOVA one-way test and post hoc test.
RESULTS: The labiopalatal fracture pattern of group A showed significantly increased resistance to fracture than the palatolabial fracture pattern of group B in both the subgroups. Similarly, subgroup II with Everstick post exhibited significantly higher fracture resistance than subgroup I with Ribbond in both groups A and B (p value < 0.05).
CONCLUSIONS: The study simulates a clinical scenario of coronal fracture of a tooth and focuses on the techniques and materials which can be used for successful management of such cases.
UNASSIGNED: Khurana D, Prasad AB, Raisingani D, et al. Comparison of Ribbond and Everstick Post in Reinforcing the Re-attached Maxillary Incisors Having Two Oblique Fracture Patterns: An In Vitro Study. Int J Clin Pediatr Dent 2021;14(5):689-692.

OBJECTIVE: The objective of our study was to compare the fracture resistance and the mode of failure among three different post materials in primary anterior teeth.
METHODS: A total of sixty extracted primary anterior teeth were selected for the study. The samples were divided into three groups of twenty teeth each: Group I (Ribbond), Group II (Omega loop), and Group III (Glass fiber post). Pulp therapy was followed by intracanal post and crown buildup. The samples were mounted in self-cure acrylic and subjected to compressive strength test using universal testing machine (Instron). The maximum force at which the tooth fractured was recorded.
RESULTS: The values were subjected to one-way analysis of variance. The mean compressive strength values of Ribbond, omega loop, and glass fiber post were found to be 83.25 N, 61.60 N, and 75.55 N, respectively. The P value was found to be 0.220.
CONCLUSIONS: Group I (Ribbond) showed the highest fracture resistance values followed by Group III (Glass fiber post) and Group II (Omega loop). Although there is difference in mean values, they were nonsignificant.

The study evaluated the adaptation and push-out bond force of two different lined fibre dowels in oval canals. Dowel spaces were prepared in 30 obturated mandibular premolars with oval roots. The samples were divided into three groups (n = 10). The first group received non-lined fibre dowels (NL). The fibre dowels in the second group were lined with a resin composite (PL). The fibre dowels in third group were lined with resin composite reinforced with polyethylene fibre ribbon (PFL). The proportion of surface area (PSA) occupied by the dowel and push-out bond force were analysed. The data were statistically analysed using two-way anova with post-hoc Holm-Sidak and Tukey tests. The PSA was higher in lined dowels. Highest push-out bond forces were recorded in PFL. Fibre reinforced composite lining improves the adaptation and push-out bond force of fibre dowel in oval canals.

The myriads of technological advancements in dentistry in last two decades have led to a dramatic shift from conventional invasive procedures to more conservative biomimetic therapies. In this series, management of traumatic dental injuries has taken a big leap in that now it is possible to conserve many of these teeth which were otherwise doomed to extraction. Depending on the extent of injury, esthetic and functional requirements, traumatic dental injuries can be managed by a variety of clinical procedures including composite resin restorations, reattachment of fractured fragment, endodontic therapy with or without post and core or lastly extraction. Reattaching natural tooth structure offers an advantage over the others in that it is instant, provides superior esthetics, preserves the natural tooth structure and is best accepted by the patient. This paper describes the comprehensive management of traumatized maxillary central incisor involving pulp exposure while maintaining pulp vitality and natural appearance of a tooth.

OBJECTIVE: To compare the fracture resistance of maxillary central incisor fragments having two different fracture patterns and re-attached using two different posts - fibre post and Ribbond.
METHODS: Sixty extracted human maxillary central incisors were randomly divided into two groups of thirty samples each. Group A consisted of samples with \'labio-palatal\' fracture pattern and Group B with a \'palato-labial\' fracture pattern. The crowns of all the samples were sectioned using safe-sided diamond discs. Following cleaning and shaping and sectional obturation, the samples were randomly subdivided into two subgroups of 15 samples each. Prefabricated fibre post (Reforpost, Angelus, Londrina, PR, Brazil) was placed in all samples of Subgroup I, and Ribbond (Ribbond Inc., Seattle, WA, USA) was placed in all samples of Subgroup II. The fragments were re-attached, fracture resistance was tested using Instron Universal Testing Machine, and the failure modes were assessed using a stereomicroscope.
RESULTS: Group A with a labio-palatal fracture pattern exhibited higher fracture resistance as compared to Group B (palato-labial) in both subgroups. The fibre post (Subgroup I) exhibited higher fracture resistance as compared to Ribbond (Subgroup II). The Ribbond group exhibited significantly more number of repairable failures as compared to fibre post group.
CONCLUSIONS: The labio-palatal pattern of fracture is a favourable type of fracture on palatal load application. The fragments re-attached using the fibre post (Reforpost) had a higher resistance to fracture. However, teeth restored with Ribbond posts exhibited 100% repairable failures upon load application. The fracture pattern had no influence on the failure modes.

Fractured teeth are always a challenge to the dentist. The root canal therapy today can retain even very badly broken teeth. One of the most accepted techniques involve restoration of extensively carious or badly fractured teeth by the fabrication of a post and core while utilizing the root canal space for anchorage. So far, the only materials that are available to the dentist for this procedure have been a variety of metallic alloys. These materials are hard and need to be cast precisely so that they can fit the canals. Today materials are available which usually eliminates all the intermediate steps which are done in laboratories and the total control is rendered in the hands of the dentist, to fabricate on the chair, a resilient, aesthetic and bonded post and core. One such material is discussed here in a pediatric permanent anterior tooth.