Monolithic Endocrown Vs. Hybrid Intraradicular Post/Core/Crown Restorations for Endodontically Treated Teeth; Cross-sectional Study

Knowledge and Practice of Endocrown Restorations Among Dental Students and Dentists in Sirte, Libya

Background Restoring endodontically treated teeth has long posed a challenge for clinicians. The endocrown (EC) is an innovative and conservative restoration designed for teeth with severely damaged coronal structures. ECs offer performance that is equivalent to or even exceeds that of traditional post-core-crown treatments. Purpose This web-based cross-sectional survey aimed to evaluate the level of knowledge and practical experience regarding ECs as post-endodontic prostheses among dental students and practitioners in Libya. Methods A 22-item structured questionnaire was created using Google Forms and distributed to final-year students, interns, faculty at the College of Dentistry at Sirte University, and practicing dentists in Libya. The sample comprised 290 participants. The questionnaire was divided into three sections: the first assessed demographic variables such as gender, education level, country of graduation, and workplace; the second evaluated knowledge of ECs through 11 questions; and the third focused on EC practice, also comprising 11 questions. Statistical analysis was conducted using IBM SPSS Statistics for Windows, Version 21.0 (Released 2012; IBM Corp., Armonk, NY, USA). Results A total of 50.7% of participants indicated that EC restorations are suitable for molar teeth, 41.4% noted that a butt joint finish line is used for EC preparation, and 66.9% preferred all-ceramic materials for ECs. Nearly 72.8% reported that computer-aided design/computer-aided manufacturing technology is employed for EC fabrication. Additionally, 61.7% agreed that EC designs offer higher fracture resistance compared to conventional crowns. Despite this, 64.5% of participants had not cemented an EC in their clinic in recent years. Significant differences in knowledge and practice regarding ECs were observed across various factors, including gender, education level, country of graduation, and workplace. Conclusion Most participants demonstrated an acceptable level of knowledge and practical experience with EC restorations. Therefore, incorporating ECs as a major topic in the postgraduate prosthodontics curriculum is recommended.

Roughness analysis on porcelain sectional surface of porcelain fused to Co-Cr alloy endocrowns

This study aims to compare the roughness between the central and edge points on the porcelain sectional surface of porcelain fused to Co-Cr alloy endocrowns. Utilizing anatomical data from average molar dimensions, a simplified model for the endocrowns was created. Eight porcelain fused to Co-Cr alloy endocrowns were fabricated with an edge thickness of 0.3 mm. Following casting, firing, cutting, and polishing procedures, the roughness on porcelain sectional surface at both the central and edge points of the inner crown was assessed using an atomic force microscope (AFM). The roughness measurement (Sq value) for the central point on porcelain sectional surface was (10.46 ± 3.37 nm), and for the edge point, it was (10.50 ± 1.99 nm). There was no statistically significant distinction between the central and edge points in terms of roughness. Despite the uneven thickness of the inner crown in porcelain fused to Co-Cr alloy endocrowns, it was observed that this disparity had negligible impact on the internal microstructure of the porcelain. Therefore, its application in dental clinical settings could be deemed viable.

Evaluation of custom posts and cores fabricated by two digital technologies in core and post space dimensions

PURPOSE

To evaluate the adaptability between posts and post spaces and the rationality of cores fabricated by two digital custom post-and-core processes.

MATERIALS AND METHODS

Titanium post-and-cores were fabricated by digital scanning impression technology or digital scanning wax-pattern technology on tooth defect molds of incisors, premolars, and molars, with traditional lost-wax casts of these teeth as the controls. Micro-CT and a laboratory scanner were used to determine intervals between post wall and root canal wall of the root apex, middle, and cervix of each sample in cross-, sagittal, and coronal sections; intervals between the end of post and tooth; diameters of cervical, middle, and incisal part at cross-, sagittal, and coronal sections of each sample, as well as shoulder widths.

RESULTS

The three fabrication processes showed significant differences in intervals between post-and-core prostheses and root canal walls, diameters of all parts of cores, and shoulder widths. Scanning impressions showed significant advantages in the main part of post-and-cores in incisors and premolars, while the scanning wax-pattern process showed obvious inferiorities in premolars and molars. As to core spatial size, values of measured sites in the scanning impression process were closer to the standard than those of the traditional process, while differences between the measured value of the scanning wax-pattern process were much more obvious than in the traditional process.

CONCLUSIONS

The use of digital custom post-and-core scanning impressions improved the rationality and precision of post-and-core dimensions compared with two other processes.

The influence of Zircos-E® etchant, silica coating, and alumina air-particle abrasion on the debonding resistance of endocrowns with three different preparation designs

OBJECTIVES

The study aimed to evaluate the debonding resistance of three different endocrown designs on molar teeth, using three different zirconia surface pretreatments.

MATERIAL AND METHOD

Ninety human mandibular first molars were divided into three main groups: endocrowns without ferrule, with 1 mm ferrule, and with 2 mm ferrule. The subgroups were defined by their surface pretreatment method used (n = 15): 50 μm alumina air-particle abrasion, silica coating using 30 μm Cojet™ particles, and Zircos-E® etching. The endocrowns were fabricated using multilayer zirconia ceramic, cemented with self-adhesive resin cement, and subjected to 5000 thermocycles (5-55°C) before debonding. The data obtained were analyzed using a two-way ANOVA.

RESULTS

All test specimens survived the thermocyclic aging. The results indicated that both the preparation design and the surface treatment had a significant impact on the resistance to debonding of the endocrowns (p < .001). The 2 mm ferrule followed by the 1 mm ferrule designs exhibited the highest debonding resistance, both were superior to the endocrown without ferrule. Zircos-E® etching and silica coating yielded comparable debonding resistance, which were significantly higher than alumina air-particle abrasion. All endocrowns demonstrated a favorable failure mode.

CONCLUSIONS

All designs and surface treatments showed high debonding resistance for a single restoration. However, ferrule designs with Zircos-E® etching or silica coating may represent better clinical options compared to the nonferrule design or alumina airborne-particle abrasion. Nonetheless, further research, including fatigue testing and evaluations with different luting agents is recommended.

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.

Fracture resistance of endodontically treated teeth, restored with two post-core systems in different post space diameters (in vitro study)

BACKGROUND

Fracture resistance of post-core restoration depends on the design of the post, post diameter, post length, the type of adhesive cement used along with material of the core. Despite the different studies concerning the effect of post space diameter on the fracture resistance of endodontically treated teeth, more information regarding fracture resistance and the effect of different post space systems/materials and diameters is required.

AIM OF THE STUDY

This study aimed to evaluate fracture resistance of endodontically treated teeth, restored with two post-core systems in different post space diameters.

MATERIALS AND METHODS

Twenty freshly extracted maxillary central incisors were collected for this study. They were randomly divided into four groups according to intracanal post and its diameter. Group GN (glass-fiber post of 10-mm length and 1.3-mm diameter with composite core), group GW (glass-fiber post of 10-mm length and 1.75-mm diameter with composite core), group ZN (custom-made zirconia one-piece post-core of 10-mm length and 1.3-mm diameter) and group ZW(custom-made zirconia one-piece post-core of 10-mm length and 1.75-mm diameter). Fracture resistance for all samples was evaluated using the universal testing machine under a static load. The data was collected and statistically analyzed using One-Way ANOVA test. Modes of failure were assessed using stereomicroscope for each group.

RESULTS

The highest mean fracture resistance was recorded in group GW (638.7 ± 285.1 N), followed by group ZW (598.5 ± 127.6 N), then GN group (442.8 ± 65.38 N). The lowest mean fracture resistance was recorded in group ZN (435.3 ± 117.3 N). One-Way ANOVA test revealed that there was no statistically significant difference in fracture resistance values among the groups.

CONCLUSION

Post space diameter had an impact over the fracture resistance of endodontically treated teeth. Modulus of elasticity of post material had a major effect on the fracture resistance and mode of failure along with the restorability of the restored tooth. However, there was no statistically significant difference among the tested groups.

Biomechanics of anterior endocrowns with different designs and depths: Study of finite elements

Background

To date, there is no clear consensus in the literature on which endocrown design and depth is the most effective treatment option for restoring endodontically treated maxillary central incisors. Aim: To determine the stress distribution of the anterior endocrowns by means of finite element analysis.

Material and Methods

Nine 3D finite element models (groups A - I) were made, each one representing a restoration system of endodontically treated upper central incisors. The models were endocrowns with and without ferrules at 0, 1, 3, and 5 mm depth and a post-core stump control group. A static load of 100N of force was applied to the palatal face at 45º from the long axis of the tooth. The Von Mise values and the maximum stress in the crown, dentin and resin cementum were evaluated separately.

Results

The maximum stress distribution was C < B < A < D < H < F < E < G < I and the Von Mises stresses were in the upper 1/3 of the retainer of endocrowns A, B, C and D. ; in the vestibular neck in endocrowns E and F; in the final 1/3 of the retainer in the endocrown G; in the middle 1/3 of the retainer in the H endocrown; and at the level of the vestibular neck of the crown in model I.

Conclusions

The smallest distribution of maximum and Von Mises stresses was observed in model C. Key words:Finite element analysis, Biomechanics, upper central incisor, endodontically treated teeth, dental restoration.

Knowledge and Awareness of Dental Practitioners About the Utilization of Endocrown in Post-endodontic Management

BACKGROUND

The objective of this study was to evaluate the knowledge, and awareness of dentists in Ha'il, Kingdom of Saudi Arabia, regarding the use of endocrown as post-endodontic restorations, utilizing an online questionnaire.

METHODS

A cross-sectional study was carried out among dental practitioners working in Ha'il, Kingdom of Saudi Arabia. Dentists who practice in the Ha'il were included in the current study. The survey study involved a sample size of 245 participants. The researchers employed the snowball sampling technique in this investigation. The validated, closed-ended questionnaires were disseminated to the entire sample of selected dental practitioners using electronic mail. The initial section of the survey encompassed inquiries pertaining to the demographic characteristics of the participants, encompassing variables such as gender, years of professional experience, and workplace. The subsequent section of the survey focused on assessing the participants' knowledge and opinions regarding the endocrown technique. The Chi-square test was employed to assess the associations between categorical variables.

RESULTS

The most of participants 228 (93.1%) had knowledge about endocrown and 94 (38.4%) of them received information from their educational institutions. Among the responses of the participants, 232 (94.7%) expressed their preference for utilizing endocrown restorations specifically for molar teeth. Moreover, 183 (74.7%) of respondents indicated that the endocrown is preferred when there is a restricted amount of inter-arch space available. A majority of respondents 152 (62.0%) indicated that the ferrule does not exert any influence on the endocrown. A majority of participants 135 (55.1%) expressed a preference for utilizing lithium disilicate ceramic in the fabrication of endocrown. The most of participants 209 (85.3%) opted to use resin cement for the purpose of cementation. The characteristics of gender, experience, and working place were found to have a significant relationship with the knowledge of the participants about endocrown (p <0.05).

CONCLUSIONS

The study participants need to enhance their knowledge and awareness pertaining to the utilization of endocrowns as a post-endodontic treatment.

Pre-Treatment and Post-Treatment Dental Anxiety in Patients Visiting Intern Dental Clinic

Background and Objectives: This study aimed to assess the dental anxiety of patients using the modified dental anxiety scale (MDAS) questionnaire along with examining the possible relationship between dental anxiety and sociodemographic factors. Materials and Methods: The MDAS questionnaire was used to assess the anxiety level of the patients which included a total of five questions and five options to respond to each question. MDAS questionnaire was filled out by all the patients before the dental treatment. After finishing the treatment, all the patients were given a post-treatment questionnaire to assess their anxiety levels after treatment. Descriptive statistics were performed for measuring the frequency of responses. Mann-Whitney U test was used to compare the anxiety between the gender. The chi-square test was used to identify the distribution of pre-treatment with gender and post-treatment questionnaire with gender and treatment modalities. Linear regression was used to identify the association between clinical variables and different levels of anxiety. Results: A total of 115 patients including 59 males and 56 females with a mean age of 35 ± 11.34 years were included in the current study. Female patients were significantly more anxious about dental treatment compared to male patients. Linear regression showed that age and gender have a significant association with the pre-treatment anxiety level; however, types of treatment is not associated with the MDAS. Anxiety levels decreased for the majority of the patients after the treatment and types of treatment did not show any differences with the post-treatment anxiety level. Conclusions: Age and gender play an important role in dental anxiety; however, types of treatment are not associated with pre-treatment and post-treatment dental anxiety.

Unlocking Endocrown Restoration Expertise Among Dentists: Insights from a Multi-Center Cross-Sectional Study

BACKGROUND This study, employing an online questionnaire, aimed to assess and contrast the awareness, knowledge, and perceptions of dentists in Saudi Arabia (SA) regarding endocrowns (EC) as post-endodontic restorations with those of dentists educated in various other countries. MATERIAL AND METHODS We conducted a cross-sectional survey among dental interns and practicing dentists in government facilities, private dental centers, and dental colleges in SA, including participants of diverse nationalities. We disseminated validated, closed-ended questionnaires through WhatsApp via Google Forms. The Chi-square test was applied to assess associations between categorical variables, with a P-value of ≤0.05 indicating statistical significance. RESULTS The majority of participants (61.2%) indicated that EC restorations are best suited for molar teeth. Furthermore, 69.6% asserted that the primary objective of employing EC is to accomplish minimally invasive preparations while preserving the existing tooth structure. Among the responses, 68.3% pinpointed debonding of ECs as a significant cause of failure. Notably, substantial differences were observed in responses concerning the knowledge or practice of EC across various factors such as gender, educational attainment, country of graduation, and workplace. CONCLUSIONS The findings reveal a comparatively low adoption of ECs among the participants, irrespective of experience or country of education. This underscores the need for incorporating ECs into dental curricula through theoretical and clinical discussions or considering them as a subject for post-graduate continuing education programs.

Comparison of the measurement error of optical impressions obtained with four intraoral and one extra-oral dental scanners of post and core preparations

Statement of problem

Innovations in intraoral scanner (IOS) technology are opening up ever more indications for computer-aided design and manufacturing (CAD-CAM). The manufacturers claim that the latest generations of scanners allow the digitizing of root canal preparations. However, there is a lack of studies evaluating the quality of the optical impressions made for this type of treatment.

Purpose

The purpose of this study was to evaluate the measurement error of 4 IOSs and a laboratory scanner used for the digitizing of root canal preparations and to highlight the effect of the presence or absence of adjacent teeth on the quality of the digital model.

Material and methods

Two models: one presenting adjacent teeth, one without adjacent teeth, both presenting a 10 mm deep nominal conical pit mimicking a root canal preparation were fabricated. Each model was scanned 10 times with a laboratory scanner (E3) and 4 intraoral scanners (Primescan, Omnicam, TRIOS 4, and Medit i700). The digital models were then exported as standard tessellation language (STL) files and analyzed to evaluate the mean measurement error of the digitizing of the root preparation at three different depths: 0-3 mm, 3-6 mm, and 6-9 mm. Significant differences were assessed with a 1-way ANOVA test and the pairwise comparison between scanners was done by Tukey's multiple comparison test.

Results

Statistical differences were found between scanners (P < 0.05). The mean measurement error ranged from 9.8 ± 0.5 μm with the Medit i700 to 28.2 ± 10 μm with the E3. The E3 and Omnicam scanners were in some cases incapable of digitizing the conical preparation in its entirety. The group Primescan, TRIOS 4, and Medit i700 showed minimally significant differences. The presence of adjacent teeth had a negative effect on the model quality for some scanners, mainly because of the obstruction of the IOS's head.

Conclusions

Significant differences were found among the dental scanners used for digitizing root canal preparations. Optical impressions with modern intraoral scanners seem to be an adapted method of registration of root canal preparation for post-and-copings of post-and-cores fabrication.