Interocclusal Space Research Articles

Create virtual dentoskeletal model by superimposing digital dental cast into cone-beam computed tomography scan.

Many artifacts and obstacles associated with cone-beam computed tomography (CBCT) scan can obscure or distort the details of the teeth and occlusal surface, like distorted teeth, streak artifacts, noise, and some malocclusion cases with excessive overlapping between jaws cause decrease the interocclusal space, which can impact diagnosis and treatment planning, and the 3D reconstruction accuracy. Optimizing dental precision by Integrating CBCT scans with other imaging modalities, supply more information to enhance CBCT accuracy, mainly in dental areas with limited clarity. Performing the Structure-from-Motion (SfM) photogrammetry method, using phone camera and photograph studio setup using simple hardware, to digitize the dental casts and obtain an accurate digital dental model. Using this digital dental model to enhance dental precision in the CBCT data by performing the superimposition process, using a surface-based registration method and integration process to create a virtual dentoskeletal model. Evaluate the accuracy and quality of the superimposition results using qualitative (visual inspection) and quantitative measures. The differences between the virtual dentoskeletal model and the reference CBCT model are calculating by the 3D Euclidean distance, the mean ± SD are 0.212 ± 0.169mm and 0.26 ± 0.149mm for the maxilla and mandible, respectively. The color-coded map shows that the two surfaces are similar, but the extremist values are concentrated in the dental region due to the presence of the noise in the reference model and the gingiva in the virtual dentoskeletal model. The resulting virtual dentoskeletal model can be viewed and manipulated on a computer screen, allowing for a detailed analysis of the teeth and supporting structures. The 3D model generated by the SfM photogrammetry technique did well during the superimposition process, representing a reliable method for virtual-based processing such as orthognathic surgery planning and splint design.

Overview on Restoration with Endocrown

Endocrown restorations are single prostheses that are made of reinforced ceramics and may be acid etched; they are recommended for endodontically treated molar teeth that have suffered a considerable loss of coronal structure. In order to provide a strong foundation for the restoration and strengthen the restored tooth structurally, the quality and integrity of the residual tooth structure should be carefully preserved. For this reason, Endocrown is used as a minimally invasive technique. Endocrowns are particularly recommended for molars with short, destroyed, dilacerated, or unstable roots. They may also be utilized when it is unable to achieve an acceptable thickness of the ceramic coating on the metal or ceramic substructures due to significant coronal dental tissue loss and constrained interocclusal space. Endocrowns provide a more beneficial choice than conventional and post- and core-retained restorations because of the little and simple preparation required. This favorable outcome can be attributable to a number of variables, including the preparation method, occlusal thickness, and elastic moduli. When it comes to material selection it is impossible to create what is called the material of choice since new material is constantly being introduced.

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.

Treatment of localized anterior toothwear with composite restorations at an increased occlusal vertical dimension

Patients may present with localized anterior toothwear, complaining of poor appearance or sensitivity. or both. Restoration of these teeth continues to cause problems, especially if interocclusal space has been lost. Conventional treatment to satisfy the patient's aesthetic and functional demands is time consuming and requires careful maintenance. This paper describes the use of chairside composite resin restorations in the treatment of localized anterior toothwear. lnteroccusal space is provided by placing the restorations at an increased vertical dimension of occlusion. It enables the presenting complaint to be resolved while restoring structure, function and appearance. CPD/Clinical Relevance: Localized anterior toothwear may be treated in suitable cases by placement of palatal composite restorations, with posterior tooth contact normally being re-established within 6 months. Original article reproduced in full from: Darbar UR, Hemmings KW. Treatment of localized anterior toothwear with composite restorations at an increased occlusal vertical dimension. Dent Update 1997; 24: 72–75. (Please note that the figures have been reproduced from the original printed version.)

Positional trueness of three removable die designs with different root geometries manufactured using stereolithographic 3D printing

Statement of problemThree-dimensional (3D) printed casts are a suitable alternative to dental stone casts. Contemporary dental design computer programs permit designing definitive casts with removable dies with different root geometries and retention mechanisms. Studies on the positional trueness of 3D-printed removable dies with different root geometries are lacking. PurposeThe purpose of this in vitro study was to investigate the 3D displacements of three 3D-printed removable die designs with different root geometries. Material and methodsThe digital file of a dental stone alveolar cast with root-form removable dies (MOD UJ IV Fixed Prosthetics; Ivoclar AG) was used as a reference to create 3 removable die and alveolar cast designs (Root Form, RF; Conical, CON; Cylindric, CYL) with different root geometries in 2 dental design computer programs (DentalCAD 3.1 Rijeka; exocad; GmbH; InLab CAD 22.0; Dentsply Sirona). 3 equidistant Ø1-mm spheres (C, Cervical; M, Middle; O, Occlusal) were designed on the buccal surface of the coronal portion of the removable die to evaluate their displacement. A total of 45 alveolar casts with 45 removable dies were fabricated using a stereolithographic 3D printer (Form 3; Formlabs); each die group consisted of 15 specimens. After fabrication and postprocessing, the specimens were scanned, and their digital files were analyzed in a metrology-grade computer program to evaluate the displacement of the removable dies with respect to the position of the die in the master reference file. Subsequently, the data were analyzed using a 3-way analysis of variance (ANOVA) followed by step-down Bonferroni-corrected pairwise comparisons (α=.05). ResultsTwo statistically significant 2-way interactions were detected between the independent variables, die design and direction (P<.001), and location and direction (P<.001). The post hoc analysis identified significant differences between the displacement values of RF and CYL (P<.001) and RF and the CON (P<.001) designs on the Y axis. The measured displacements were statistically different between the C and O locations on the Y axis (P=.001) and the M and O locations on the Z axis (P=.006). ConclusionsThe root geometry of a 3D-printed removable die and alveolar cast can affect seating, and variable degrees of tipping of the removable die can be seen. The seating and congruence of the removable die with the interocclusal space and relationships observed intraorally should be confirmed before adjusting indirect restorations.

Factors that influence the accuracy of maxillomandibular relationship at maximum intercuspation acquired by using intraoral scanners: A systematic review

ObjectiveTo review the factors that influence the accuracy of the maxillomandibular relationship at maximum intercuspation (MIP) acquired by using intraoral scanners (IOSs). Material and methodsA systematic search was performed using five databases: MEDLINE/PubMed, Cochrane, Embase, World of Science, and Scopus. A manual search was also completed. Studies assessing the factors that influence the MIP acquired by using IOSs were included and organized based on the analyzed factor. Studies were evaluated by applying the Joanna Briggs Institute Critical Appraisal Checklist. ResultsTwenty-nine articles were included. Seven factors have been identified: IOS system, scan extension, edentulous areas, number, location, and extension of occlusal records, occlusal force, tooth mobility, and alignment methods. Nine studies evaluated the influence of IOS system. Four studies assessed the influence of the extension of the arch scan. Three studies evaluated the effect of edentulous spaces. Four studies agreed on the impact of the number, location, and extension of the occlusal records on the MIP accuracy. One study assessed the influence of the occlusal force, showing a smaller average interocclusal space with increased occlusal force. One study evaluated the influence of tooth mobility. Seven studies analyzed the influence of the alignment method on the MIP accuracy. ConclusionsMost of the studies reported no difference on the MIP accuracy between half- and complete-arch scans. Areas with 2 or more missing teeth reduce the MIP accuracy. A bilateral and frontal record including 2 teeth or a bilateral posterior occlusal including at least 4-teeth is indicated for maximizing the MIP accuracy. Clinical implicationsWhen a complete-arch intraoral scans is obtained, a bilateral and frontal record including 2 teeth or a bilateral posterior occlusal record including at least 4-teeth is recommended for maximizing the accuracy of the MIP. When a half-arch intraoral scan is acquired, a posterior occlusal record including at least 4-teeth is indicated for optimizing the accuracy of the MIP.

Evaluation of video teaching on resident competency for all-ceramic crown tooth preparation.

This study aimed to analyze the impact of live video instruction using digital evaluation of residents' performance in full ceramic crown preparation. Digital evaluation using CEREC computer-aided design/computer-assisted manufacturing (CAD/CAM) 5.1.3 software was conducted of preparation on a typodont for all-ceramic crowns of mandibular first molars (MFMs) with a radial shoulder finish line, carried out by 30 residents. Each participant prepared two MFMs: group A prepared the right side without live video instruction, and group B prepared the left side after instruction. All prepared teeth were scanned by Dentsply Sirona chairside CAD/CAM system with Omnicom to assess the inter-occlusal space, undercut, the finish line of the preparation, and surface texture. The data were analyzed using Pearson Chi-square, Wilcoxon signed-rank test, and paired t-test. P-values less than 0.05 were considered to be statistically significant in all tests. Based on the Pearson Chi-square test, there were significant differences between the two groups in terms of inter-occlusal space on the buccal and lingual surface of the prepared tooth, in the presence of rough surfaces before and after the preparation, and difference in the type of finish line. The Wilcoxon signed-rank test revealed a significant difference in convergence angle buccolingually and the remaining height of the prepared teeth before and after the video instruction. The use of educational live video instruction can be helpful to residents in learning the principles of tooth preparation.

Http://journals.khalijedental.com.ly/index.php/ojs/article/view/55

Background and objectives. Many dental practitioners have always struggled with obtaining aesthetic restorations while preserving the remaining dental structure. The purpose of this study is to investigate the relationship between the occlusal thickness and fracture resistance of CAD/CAM monolithic zirconia restorations to determine the feasibility of reducing the occlusal thickness, particularly in the posterior area, where inter-occlusal space is typically limited and high biting forces are applied. Methods. Four experimental groups were created using thirty-two CAD-CAM monolithic zirconia crowns with different occlusal thicknesses: 2.0 mm (group 1), 1.5 mm (group 2), 1.0 mm (group 3), and 0.5 mm (group 4). Self-adhesive resin cement was used to cement the restorations to human molars. Loading the specimens until fracture occurred, and the fracture resistance and mode of failure were recorded. The data were statistically analyzed using a one-way ANOVA followed by Fisher's exact test. Results. All specimens' fracture resistance values exceeded the maximum physiological occlusal loads in molar areas, and all of the crowns had consistent microcracks. A complete fracture was only interested in one crown with a thickness of 0.5 mm. Conclusion. The occlusal thickness of CAD-CAM monolithic zirconia crowns can be decreased to 0.5 mm while still being strong enough to sustain occlusal loads.

Survival analysis of zirconia implant-supported, fixed complete dentures: A 5-year retrospective cohort study.

Existing data on the mid-term to long-term survival rates of zirconia implant-supported, fixed complete dentures (Zir-IFCDs) are lacking. The purpose of this retrospective clinical study was to assess the prosthetic survival rate in patients treated with Zir-IFCDs. The patient record system at the Dental College of Georgia (DCG), Augusta University was searched to identify all patients treated with Zir-IFCDs from 2015 through 2022 by the DCG graduate prosthodontic, general practice residency, and Advanced Education in General Dentistry (AEGD) programs. Reasons for replacement were grouped as failure of veneering porcelain, framework fracture, implant loss, patient-driven concerns, excessive occlusal wear, and other. A total of 67 arches were found that met the inclusion criteria, 46 maxillary and 21 mandibular. The median follow-up time was 8.5 months (interquartile range, 2.7 to 30.9 months). A total of 9 of the 67 arches were identified as having failed (4 maxillary, 5 mandibular), requiring replacement. Reasons for failure were as follows: 3 framework fractures, 2 implant losses, 2 patient-related concerns, 1 fracture of veneering porcelain, and 1 unknown. The combined survival rate (Kaplan-Meier, log-normal modeling) for Zir-IFCDs was 88.8% at 1 year and 72.5% at 5 years CONCLUSIONS: Based on the findings, the Zir-IFCDs investigated had a survival rate lower than that reported in similar studies, though higher than published results for metal-acrylic resin-IFCDs. The most common source of failure was fracture of the zirconia framework. Thickness of the zirconia framework, interocclusal space, cantilever length, occlusal force, and status of the opposing dentition may have been associated with framework failures and should be investigated further.

Conservative Management of Extensively Damaged Endodontically Treated Tooth using Ceramic Endocrown and Deep Margin Elevation: A Clinical Report

Introduction: The restoration of endodontically treated molar continued to be a challenging issue. After endodontic treatment, generally the tooth is exposed to a higher risk of fracture. Endocrown as a minimal invasive restoration could be a wise alternative for restoring molars with large coronal destruction and limited interocclusal space. Observation: Through this work, we present a clinical case report of an endocrown-type restoration, fabricated from lithium disilicate ceramic (IPS e.Max CAD) in a maxillary first molar with extensive coronal destruction associated to cervical margin relocation. Discussion: We discuss the indication and use of endocrown to replace single crowns with intraradicular retention. The supragingival margins of the endocrown preparation simplify rubber dam isolation, and the adhesive procedure that’s why deep marginal elevation in this case was performed.

Treatment of reduced interocclusal space with a cone crown telescopic denture after increasing the vertical dimension of occlusion: A case report

Treatment of reduced interocclusal space with a cone crown telescopic denture after increasing the vertical dimension of occlusion: A case report

Surgical restoration of interocclusal space and maxillary sinus floor elevation for prosthetic purposes

Aim: To report on a surgical procedure with osteotomy in the posterior region of the maxilla and lifting of the maxillary sinus floor for the installation of implants and rehabilitation with implant-supported crowns. Case report: A 54-year-old female patient was admitted to the dental clinic, complaining that she was dissatisfied with her smile and the missing teeth. After the clinical, radiographic, and tomographic examinations, a well as a case study of a semi-adjustable articulator, multidisciplinary planning was carried out using surgical, endodontic, periodontic, orthodontic, and prosthetic approaches. A lack of interocclusal space was observed in the posterior region of the maxilla. After osteotomy in tuberosity, maxillary sinus lift using an autogenous bone graft was performed, and three implants were installed. After the osseointegration period, provisional crowns were placed, followed by definitive metal-ceramic crowns. Conclusion: The surgical techniques used in this clinical case made it possible to install implants in a single clinical session for prosthetic rehabilitation.

The advancement of adhesive dentistry with the endocrown technique and its diffusion among professionals: a literature review

Introduction: In the decades with the advancement of materials fabrication, such as restorations with the latest improvements in their dental fabrication process, or as restorations with improvements in their dental fabrication process, or as the latest restorations in their dental fabrication process, dentistry, or as the latest restorations in their restorative materials manufacturing process. Objective: This work aims to demonstrate through a literature review the use of the endocrown technique. Methods: The research was carried out from January to May 2022 and was developed based on PubMed, Scielo, and Google Scholar. Results: There were 11 a total of 13 articles on Endocrowns. In total, 47 articles were complete and 19 were included in this study. Dentistry, contributing to a better resolution of cases, presents little interocclusal space, so the indirect endocrown restoration technique becomes an excellent option, presenting a good alternative and less dental wear for making. Conclusion: It was concluded that the use of the endocrown technique has shown, for the most part, employing clinical results that it is an excellent restorative option for the restoration of molars with great coronary destruction, and its clinical survival rate was comparable to the use of intraradicular posts of fiber.

Does the available interocclusal space influence the accuracy of the maxillomandibular relationship captured with an intraoral scanner?

Statement of problemThe accuracy of a maxillomandibular relationship acquired by intraoral scanners (IOSs) has been previously analyzed; however, the impact of the interocclusal space on the accuracy of the maxillomandibular relationship remains unknown. PurposeThe purpose of this in vitro investigation was to evaluate the influence of the interocclusal space (0, 1, 2, 3, or 4 degrees of incisal opening in the articulator) on the accuracy of the maxillomandibular relationship captured with an IOS. Material and methodsMarkers were attached to the first molars and canines of maxillary and mandibular diagnostic casts, which were mounted on a semi-adjustable articulator, and digital scans were acquired (TRIOS 4). Both digital scans were duplicated 100 times and distributed into 5 groups depending on the incisal pin opening in the articulator (n=20): 0 (Group 0), 1 (Group 1), 2 (Group 2), 3 (Group 3), and 4 degrees (Group 4). In Group 0 (control), the casts were maintained in maximum intercuspation (MIP) with the incisal pin of the articulator set at 0 degrees. Then, a bilateral virtual occlusal record was acquired and automatically processed by using the IOS software program. A laboratory scanner (Medit T500) was used to digitize the mounted casts. The same procedures were completed in Groups 1, 2, 3, and 4 but with the incisal pin set at 1, 2, 3, and 4 degrees respectively. The interlandmark distances were used to calculate the discrepancies between the control and groups tested. One-way analysis of variance (ANOVA) and pairwise comparison Tukey HSD tests were used to inspect the data (α=.05). ResultsThe interocclusal space available when capturing the occlusal records affected the trueness of the maxillomandibular virtual relationship measured (P<.001). Group 0 (135 μm) obtained the highest distortion, while Group 3 (73 μm) and Group 4 (71 μm) showed the lowest distortion. Additionally, the interocclusal space available (P<.001) impacted the precision of the maxillomandibular virtual relationship measured. Group 0 (111 μm) obtained the highest distortion, while Group 4 (precision mean value of 59 μm) had the lowest distortion among the groups tested. ConclusionsThe interocclusal space available when acquiring virtual bilateral occlusal records using the IOS tested impacted the accuracy of the maxillomandibular relationship. The smallest available interocclusal space tested (maximum intercuspation) showed the worst trueness and precision mean values, while the group with the largest interocclusal space available had the highest trueness and precision mean values among the groups studied.

Multidisciplinary management of an enamel–dentine crown fracture with insufficient inter-occlusal restorative space: A case report

Dental trauma occurs commonly in young patients, can be complex to treat and can have negative psychological and social impacts on patients' lives. This case report outlines a multidisciplinary team approach to restoration of a traumatized anterior tooth with delayed presentation, insufficient inter-occlusal space for restoration and history of multiple failed restorations. This case report demonstrates orthodontic and restorative techniques for the management of insufficient inter-occlusal space and the indirect restoration of a traumatized anterior tooth. CPD/Clinical Relevance: A multidisciplinary team approach can be used to reorganize a patients' occlusion to provide the inter-occlusal space required to provide restorations.

Creating space for a resin-bonded fixed partial denture retainer by using the Dahl concept

A technique is presented for creating interocclusal space for a resin-bonded fixed partial denture retainer by applying the Dahl concept. A missing mandibular first molar was replaced with a cantilevered resin-bonded fixed partial denture and had been successfully retained at the 9-year clinical review.

Life changing dentistry with Full Mouth Rehabilitation – a case report

Tooth wear is caused by a variety of reasons, many of which are unknown. Tooth wear management is difficult and complex. For effective treatment, accurate measurement of occlusal vertical dimension (OVD), interocclusal rest space, and centric relation records are required. The analysis of facial soft tissue contours is very crucial. A clinician must remember two things before treating a case with full mouth rehabilitation; severe wear does not always cause loss of OVD and it also does not eliminate all defective occlusal interferences. A systematic method may be beneficial in achieving a predictable and desirable result. This paper describes the step-by-step treatment of a 63-year-old patient who had lost occlusal vertical dimension due to parafunctional habits. Making occlusal overlay bilateral splints in acrylic resin and provisional restorations in mandibular teeth for the healing of the intermaxillary distance was the first strategy for oral rehabilitation. The ultimate rehabilitative therapy evolved into direct composite resin restorations associated with all-ceramic crowns fortified by lithium disilicate after the patient's adaption and muscle stability to the new occlusal situation. We established that all teeth had solid connections with similar intensity in centric relation, as well as anterior guiding in line with functional jaw movement. Update Dent. Coll. j: 2022; 12(1): 40-44

Occlusal Metal Onlays in Complete Dentures

Flabby tissues and enlarged maxillary tuberosities in completely edentulous patients arise as a consequence of combination syndrome which affects complete denture treatment planning. A completely edentulous 70-year-old male denture wearer is presented in this article with flabby tissues and enlarged maxillary tuberosities. Flabby tissues need to be recorded in an undisplaced state to avoid overcompression due to realeff effect. Wear of acrylic teeth and perforation of denture base in the posterior region of his existing denture denotes a lack of interocclusal space. This is due to downward displacement of maxillary tuberosities which affects the posterior interocclusal space and requires special consideration. This article describes the prosthodontic management of the presented challenges with regard to the impression technique used to record flabby tissue and the need to maintain the occlusal vertical dimension to prevent denture base wear using occlusal metal onlays.

Evaluation of intraoral optical scanning accuracy for fine structure reconstruction and occlusal records of inlay/onlay preparations.

The present study aimed to determine the impact of different degrees of salivary contamination and variations in occlusal force during intraoral scanning of inlay/onlay cavities on the accuracy of fine structure reconstruction and occlusal records. Digital data of inlay/onlay models, collected using an intraoral scanner, were divided into 40 groups according to the restoration type (onlay or inlay), salivary contamination level (none, completely dry; mild, moist but not visually completely apparent; moderate, half-filled cavity; severe, filled-up cavity), and simulated occlusal force (0, 2, 4, 6 or 8 kg). The acquired 120 datasets were used to measure the average interocclusal space and cavity buccolingual internal angle. Salivary contamination and occlusal force did affect the occlusal contact (P < 0.001), but restoration type did not (P > 0.05). An interaction was found between inlay type and salivary contamination (P < 0.001), but not between occlusal force and salivary contamination (P > 0.05). Salivary contamination also affected the accuracy of fine structure reconstruction (P < 0.001), but restoration type did not (P > 0.05), and no interaction was found between the two factors (P > 0.05). The difference in the measured internal angle increased with the increase in salivary contamination. Intraoral optical scanning of inlay/onlay preparations was reliable for recording occlusal contact but showed uncertainty in cavity fine structure reconstruction when moderate or severe salivary contamination was present in the cavity. Nevertheless, a moist cavity surface with no visually apparent salivary contamination is acceptable. (Int J Comput Dent 2022;25(3):257-265; doi: 10.3290/j.ijcd.b2599691).

USE OF TEMPORARY ANCHORAGE DEVICES IN INTRUSION OF SUPRAERUPTED MOLARS-CASE REPORTS

Early loss of mandibular permanent molars with supraeruption of maxillary permanent molars is a common clinical finding causing functional posterior occlusion problems. Rehabilitation of the stomatognathic system often requires preprosthodontic intervention with molar intrusion which is one of the most difficult movements in orthodontic mechanics requiring efficient anchorage to achieve success. The aim of this article was to present two case reports, with orthodontic mini-implants used for molar intrusion as preprosthetic treatment, reducing the need for prosthetic crown reduction in patients with edentulous space discrepancy. With the aid of chain elastics, the force of intrusion passing through the center of resistance of the tooth, supraerupted maxillary molars were intruded approximately 0.5mm per month. The intrusive tooth movement maintained the vitality of the intruded teeth and was not aggressive to the periodontal structures, did not cause root resorption and no change of the pulp flow was detected. In contrast to traditional orthodontics, mini-implants were demonstrated to be clinically efficient in providing sufficient anchorage against orthodontic forces. With these devices using well-controlled magnitude and direction of the force, we reestablished successfully the functional posterior occlusion. Through this case reports, we emphasize the versatility of orthodontic mini-implants as a form of temporary anchorage devices (TADs) in the biomechanics of molar intrusion attempted to create interocclusal space for adequate prosthodontic restoration with osseointegrated implants and prosthesis. Keywords: Temporary anchorage devices (TADs), Mini-implants, Molar intrusion, Edentulous space discrepancy, Preprosthodontic therapy.