Interocclusal Relationship Research Articles

Replacing Missing Teeth with Screw-Cement Retained Implant Supported Fixed Partial Denture: A Case Report

An accurate impression with proper interocclusal relationship are the two essential criteria used for the best fit and functionality of the final prosthesis when replacing a partly edentulous arch with an implant-supported fixed partial denture. A detailed process about the open tray impression technique and registering the interocclusal relationship for implant- supported partial denture has been described in this case report.

Assessment of the Capability to Accurately Capture the Vertical Relationship by the Various Bite Registration Materials

ABSTRACT Background: This research study aimed to evaluate and compare the capability of four various bite registration materials to reproduce precise interocclusal relationships in the vertical dimension Materials and Methods: Ideal maxillary and mandibular casts were mounted on the semi-adjustable articulator in maximum intercuspation after mock tooth preparation on 46, 47, and 48. Models were scanned by the Medit T500 Dental Lab Scanner, and initial reading was noted at the predetermined points. Ten interocclusal bite registrations were made using four materials (CADbite, Jet Bite, Ramitec, and Aluwax). The mandibular model was demounted and again remounted using the interocclusal records, and the final reading was noted after scanning. Results: Ramitec showed superior results when compared to polyvinyl bite registration material and Aluwax, but the differences between Ramitec, CADbite, and Jet Bite were nonsignificant. Conclusions: Although all four materials are suitable for clinical use, elastomeric materials showed superior results. In that, polyether was found to be the best.

Trueness of 4 sectional-cast digital methods for transferring the interocclusal relationship in complete mouth rehabilitation

An accurate digital workflow for transferring the interocclusal relationship from complete arch diagnostic interim restorations to complete arch tooth preparations is essential in complete mouth rehabilitation. However, research on the accuracy of digital cross-mounting methods is lacking. The purpose of this in vitro study was to compare the trueness of 4 sectional-cast digital cross-mounting methods in transferring the interocclusal relationship for complete mouth rehabilitation. Maxillary and mandibular anatomic typodonts were used to build complete arch tooth preparations and diagnostic interim restorations for complete mouth rehabilitation in vitro. Four sectional casts were designed: an anterior cast (AR), a posterior cast (PO), a unilateral cast (UL), and a tripod cast (TR). Both extraoral scanning (EOS) and intraoral scanning (IOS) were used to obtain intermediate digital sectional casts, which were cross-registered with diagnostic interim restorations and definitive casts to transfer the interocclusal relationship. Trueness was determined by assessing tooth distance deviation and mandibular 3-dimensional (3D) deviation. Differences among the 4 sectional-cast methods were analyzed with the Kruskal-Wallis test, and differences between the 2 scanning methods were analyzed with the Mann-Whitney U test (α=.05). Significant differences in the trueness of interocclusal relationship transfer were observed among the 4 sectional-cast methods (P<.05). Regarding tooth overall distance deviation, TR-EOS found no statistically significant difference compared with PO-EOS (P>.05), but TR-EOS had half the overall distance deviation of PO-EOS. Both TR-EOS and PO-EOS had smaller deviations than the AR-EOS and UL-EOS groups (P<.05). TR-IOS had a smaller distance deviation than the AR-IOS, PO-IOS, and UL-IOS groups (P<.05). The overall distance deviation of EOS was significantly smaller than that of IOS in the TR and PO groups (P<.05). Regarding mandibular 3D deviation, TR-EOS found no statistically significant difference but had half the root mean square (RMS) of 3D deviation compared with the PO-EOS groups (P>.05). Both TR-EOS and PO-EOS groups had a smaller RMS than the AR-EOS and groups (P<.05). The TR-IOS group had a smaller RMS than the AR-IOS, PO-IOS, and UL-IOS groups (P<.05). The 3D deviation of EOS was significantly smaller than that of IOS in the PO group (P<.05). Both EOS and IOS with the tripod sectional-cast digital method accurately transferred the interocclusal relationship for complete mouth rehabilitation.

A novel method for testing accuracy of bite registration using intraoral scanners.

The evidence on the accuracy of bite registration using intraoral scanners is sparse. This study aimed to develop a new method for evaluating bite registration accuracy using intraoral scanners. Two different types of models were used; 10 stone models and 10 with acrylic resin teeth. A triangular frame with cylindrical posts at each apex (one anterior and two posteriors) was digitally designed and manufactured using three-dimensional (3D) printing. Such a structure was fitted in the lingual space of each maxillary and mandibular model so that, in occlusion, the posts would contact their opposing counterparts, enforcing a small interocclusal gap between the two arches. This ensured no tooth interference and full contact between opposing posts. Bite registration accuracy was evaluated by measuring the distance between opposing posts, with small values indicating high-accuracy. Three intraoral scanners were used: Medit i500, Primescan, and Trios 4. Viewbox software was used to measure the distance between opposing posts and compute roll and pitch. The average maximum error in interocclusal registration exceeded 50 μm. Roll and pitch orientation errors ranged above 0.1 degrees, implying an additional interocclusal error of around 40 μm or more. The models with acrylic teeth exhibited higher errors. A method that avoids the need for reference hardware and the imprecision of locating reference points on tooth surfaces, and offers simplicity in the assessment of bite registration with an intraoral scanner, was developed. These results suggest that intraoral scanners may exhibit clinically significant errors in reproducing the interocclusal relationships.

Maxillary and mandibular complete-arch implant rehabilitation using a complete digital workflow: A case report.

This paper summarizes the clinical steps involved in maxillary and mandibular complete-arch implant rehabilitation using a complete digital workflow. The maxillary arch was recorded was using the double digital scan technique, and the mandibular arch using the triple digital scan technique. The digital protocol used in this case report allowed the recording of implant positions via scan bodies, soft tissues, and, most importantly, interocclusal relationship in the same visit. A new technique for mandibular digital scan was described that uses soft tissue landmarks by creating windows in the patient's provisional prostheses to superimpose the three digital scans and consequently fabricate and verify the maxillary and mandibular prototype prostheses and definitive complete-arch zirconia prostheses. This article is protected by copyright. All rights reserved.

Comparison accuracy of digital and analog method using milled occlusal splints.

This clinical trial aims to compare the accuracy of interocclusal registration in centric relation taken with polyvinyl siloxane and intraoral scanner (IOS) with the fabrication of occlusal devices. Thirty-one participants were included in the trial registered at ClinicalTrials.gov (NCT05317182) receiving two different occlusal devices from two different workflows. One workflow was performed using polyvinyl siloxane impression material and the other with IOS. Every splint was scanned before and after the occlusal adjustments to compare the volumetric changes using the Root Mean Square deviation (RMS). Furthermore, three evaluators assessed the 3D comparison using color maps in a Visual Analog Scale (VAS). The average values of RMS were higher for the analog approach (0.01 ± 0.067) than the digital approach (0.065 ± 0.035). However, the differences were not statistically significant (p < 0.063) between the two impression techniques. For the semiquantitative analysis performed by blinded evaluators, differences in VAS values between the impression for the digital (2.08 ± 2.4) and analog (3.80 ± 3.3) technique were statistically significant. The three evaluators agreed in more than 90% of the qualitative dichotomous evaluation. Digital impressions did not show inferior accuracy compared to conventional impressions when assessed using quantitative measurements. This clinical trial provided evidence on registering interocclusal relationship at increased vertical dimension with fully digital workflow for complete arch prosthesis.

Three-point sectional-cast digital method for transferring the interocclusal relationship for full-mouth rehabilitation of worn dentition.

For full-mouth rehabilitation of worn dentition, "diagnostic" interim restorations are required to reestablish the interocclusal relationship. It is important but challenging to transfer the interocclusal relationship and to map the basic form and contour of interim restorations to the final restorations. Alignment of interim restorations and working casts is difficult when using digital workflows because of a lack of consistent hard tissue reference points. The digital workflow presented in this study used a "3-point sectional-cast digital cross-mounting method" to transfer the interocclusal relationship during full-mouth rehabilitation. An intermediate cast was made with three interim restorations: one on an incisor and two on molars. The interocclusal relationship and occlusal morphologies of the diagnostic interim prostheses were transferred and aligned to working casts using the 3-point sectional casts.

Digital study of interocclusal contact points in patients with partial tooth loss in case of immediate and nearest implantation prosthetics

The main purpose of this study was to study the qualitative and quantitative characteristics of occlusal ratios of dentitions in patients with partial loss of teeth replaced by preliminary direct or proximal dental implantsprostheses to prevent complications on the masticatory muscles and the temporomandibular joint. The article presents a detailed analysis of the interocclusal relations of dentitions in patients with partial tooth loss before and after prosthetics, including an assessment of the interocclusal contact points, their multiplicity, uniformity and strength of masticatory pressure, the presence of premature contacts, the trajectory of the overall direction of occlusal load, occlusal balance between the left and the right sides of dentition. The assessment of interocclusal relationships in the control and main groups was carried out using an available, simple, and unbiased digital device "T-Scan III" (Tekscan, USA).

Hot water–assisted separation of mounted casts and retrieval of articulator mounting plates

Dental casts are commonly attached to dental articulators with removable mounting plates by using mounting gypsum materials such as plaster or stone.1 Some processes require that the cast be separated from their supporting media for a remount procedure.2-5 On occasion, the interocclusal relationship of the casts6,7 may have to be revised. At the completion of patient treatment, the definitive casts may be discarded, but the operator may wish to reuse the mounting plates.

Update on the parameters influencing the adjustment of the sagittal and transversal condylar inclination of dental articulators.

The literature review aimed to compile and summarize the results of research relating to the recordings of condylar displacements obtained with extraoral devices, to guide clinicians to set dental (virtual) articulator parameters. The meta-analysis was undertaken to assess the sagittal condylar inclination (SCI) and transversal condylar inclination (TCI, also known as Bennett angle) values according to horizontal reference planes, movement studied, and patient characteristics: dental status, interocclusal relationship, skeletal pattern, and signs and symptoms of temporomandibular disorders (TMD). A bibliographic search was conducted in the three following electronic databases: MEDLINE, EMBASE, and Cochrane Library and Best Evidence. The review was restricted to trials involving participants meeting the following criteria: (1) adult, (2) no previous surgery in the temporomandibular region, and (3) no serious comorbidity conditions. Descriptive statistics were calculated for all study groups and were compared by applying a one-way ANOVA. All 20 articles selected corresponded to a total of 933 subjects evaluated. The recording devices and horizontal reference planes had a significant impact on the SCI values. Age, dental status, and the presence of symptoms and signs of TMD in subjects had no influence on SCI values, unlike Angle class II, division 2, the class II sagittal pattern, or the increased vertical skeletal pattern SCI parameters (P < .05). The mean TCI value was 8 degrees and was independent of individual patient characteristics and the extraoral recording device used. For accurate kinematic simulation, the patient's personal plane of reference must be transferred to the system.

Virtual occlusal record: a literature review about the digital method

To produce prostheses through the digital flow, it is essential to transfer the correct patient’s interocclusal relationship to the digital software program, enabling the articulation of virtual models. Therefore, the aim of this study was to carry out a narrative literature review to describe and discuss aspects related to the virtual occlusal record realization, as well as its precision and accuracy in different clinical situations. Searches for scientific publications were performed in different databases and only articles in English related to the topic were selected. Different methods for the alignment of virtual models are described in the literature, the main one being the scanning of the patient in occlusion, usually in a position of maximum intercuspation. However, this technique may demonstrate disagreement with the patient's actual occlusal relationship due to several factors, and therefore studies were carried out to verify the precision and accuracy of these records. Most studies use plaster models and industrial scanner to capture the record, with few studies performed with intraoral scanner in patients. Despite the various scanner systems available and the different ways of evaluating them, in general, the studies show an adequate precision and accuracy of virtual occlusal records of dentate models. However, the absence of dental elements is related to the lower accuracy of these records, it being necessary to establish an appropriate method of scanning for these clinical situations.

Interocclusal relationship transfer for full-mouth rehabilitation: step by step

Interocclusal relationship transfer for full-mouth rehabilitation: step by step

Digital Duplication and 3D Printing for Implant Overdenture Fabrication.

This technical report describes a workflow to fabricate an implant overdenture via digital duplication of an interim complete removable dental prosthesis and additive manufacturing (3D printing). An edentulous patient was provided with an interim maxillary denture after implant placement. After 4 months of healing, the existing interim denture was scanned, duplicated via 3D printing, and used to make the final impression, record the maxillomandibular interocclusal relationship, and transfer the esthetic information to the definitive implant overdenture. The framework of the implant overdenture was digitally designed and manufactured using a direct metal printing (DMP) system. This digital duplication workflow facilitated the implant overdenture fabrication with favorable clinical outcomes.

Clinical evaluation of the precision of interocclusal registration by using digital and conventional techniques

Statement of problemAlthough studies have evaluated the accuracy of data obtained by intraoral scanners (IOSs), studies on the precision of interocclusal registrations made with IOSs are lacking. PurposeThe purpose of this clinical study was to compare the precision of IOS interocclusal registration with that of conventional methods with a silicone impression material and a gypsum cast. Material and methodsEight participants with complete natural dentitions were enrolled. Images of their maxillary and mandibular quadrant arches and their interocclusal relationship were scanned with 2 IOSs: the 3M True Definition Scanner and the TRIOS Scanner 3. In the conventional method, impressions of complete-arch dentition and quadrant-arch dentition were made with a silicone impression material, and gypsum casts were fabricated, mounted on a dental articulator related with a silicone interocclusal record, and scanned with a 3D laboratory scanner. These procedures were repeated 4 times, and 4 sets of interocclusal registration data in standard tessellation language (STL) format were generated for each condition. Interocclusal registration precision was evaluated by determining the discrepancy of the STL data between repeated measurements by using the best-fit-algorithm method. ResultsThe average discrepancies for all participants were 25 ±12 μm for the True Definition, 31 ±7 μm for the TRIOS 3, 154 ±59 μm for the complete arch, and 128 ±33 μm for the quadrant arch. The Kruskal-Wallis test revealed that the effect of the impression methods on the discrepancy was statistically significant (P<.001). The Steel-Dwass test showed that both digital scan methods exhibited significantly smaller discrepancies than the 2 conventional methods (P=.005). ConclusionsThese results suggest that the intermaxillary relationship captured by the digital scan method by using IOSs had better precision than that obtained by the conventional method.

Influence of Edentulous Conditions on Intraoral Scanning Accuracy of Virtual Interocclusal Record in Quadrant Scan

Reproduction of the exact interocclusal relationship using digital workflow is crucial for precise fabrication of accurate prostheses. Intraoral scanner is known to be valid for the measurement of quadrants, however, the role of missing area in the quadrant scan on the virtual interocclusal record (VIR) is uncertain. This study aimed to evaluate the accuracy of VIR in quadrant scans using an intraoral scanner (IOS) under four different edentulous conditions. Eight scans per group were obtained using a laboratory scanner and three IOSs (Trios3, CS3600, i500). Based on trueness and precision, Trios3 had the best results, followed by CS3600 and i500. The trueness and precision were affected by edentulous conditions. The three IOSs showed deviation in the posterior region during assessment of VIR for the missing area with posterior support. CS3600 and i500 showed deviation in the short-span edentulous area without support. In extended edentulous condition without support, Trios3 showed overclosure, while i500 showed an angular deviation. In some groups scanned with Trios3 and i500, the tilting effect was observed. Based on the edentulous condition and type of IOS used, local or general deviations in occlusion were seen. The accuracy of VIR was dependent on accurate scan data. Thus, registration of the occlusal relationship in an edentulous area with more than two missing teeth using IOSs may be clinically more inaccurate than that with a laboratory scanner.

Immediately loaded interim complete-arch implant-supported fixed dental prostheses fabricated with a completely digital workflow: A clinical technique

A digital method for delivering an immediately loaded interim complete-arch implant-supported prosthesis is described. Reference pins were used to accurately superimpose a postoperative scan with the scan bodies in place on a preoperative scan with the framework design, including the interocclusal relationship and the occlusal scheme. A prefabricated auxiliary device was used after surgery to record the position of the implants and after scanning to obtain an accurate transfer of the implant positions by means of a free software program, allowing an excellent fit of the fabricated prosthesis. This technique can help in the fabrication of an interim prosthesis with better fit and comfort and reduced chair time than conventional techniques.

Selection of test bites records as part of a forensic bite mark analysis protocol

BackgroundTest bites have been recommended for collecting evidence of suspected dentition in bite mark analysis. However, these recommendations only suggest recording the interocclusal relationship without establishing number of records or characteristics to obtain proper records. This fails to consider not only the possibility that the recording material did not respond properly, but also that the evaluator has not detected simulations, habits or parafunctions that may affect the tests.MethodsThis research establishes differences between three wax test bites taken from the same subjects to determine if the first bite offered the best quality.ResultsNo significant statistical association was found between the number of test bites recorded and respective quality. The interrater agreement produced almost perfect and substantial agreements.ConclusionThere is no significant evidence that a first and only test bite is the highest quality test bite. Therefore, it is recommended to take more than a single bite test in controlled situations.

Integration of digital dental casts in cone beam computed tomography scans\u2014a clinical validation study

ObjectivesImages derived from cone beam computed tomography (CBCT) scans lack detailed information on the dentition and interocclusal relationships needed for proper surgical planning and production of surgical splints. To get a proper representation of the dentition, integration of a digital dental model into the CBCT scan is necessary. The aim of this study was to validate a simplified protocol to integrate digital dental models into CBCT scans using only one scan.Materials and methodsConventional protocol A used one combined upper and lower impression and two CBCT scans. The new protocol B included placement of ten markers on the gingiva, one CBCT scan, and two separate impressions of the upper and lower dentition. Twenty consecutive patients, scheduled for mandibular advancement surgery, were included. To validate protocol B, 3-dimensional reconstructions were made, which were compared by calculating the mean intersurface distances obtained with both protocols.ResultsThe mean distance for all patients for the upper jaw is 0.39 mm and for the lower jaw is 0.30 mm. For ten out of 20 patients, all distances were less than 1 mm. For the other ten patients, all distances were less than 2 mm.ConclusionsMean distances of 0.39 and 0.30 mm are clinically acceptable and comparable to other studies; therefore, this new protocol is clinically accurate.Clinical relevanceThis new protocol seems to be clinically accurate. It is less time consuming, gives less radiation exposure for the patient, and has a lower risk for positional errors of the impressions compared to other integration protocols.

Interocclusal registration for diagnosis and treatment planning for implant restorations

This paper describes a new technique to record the interocclusal relationship of an implant case where multiple posterior teeth are missing and need to be replaced by implant restorations. In the case presented, an appliance was designed to be supported only by hard immovable tissues; teeth that provide a precise fit of records. The well-fitting appliance can be used to accurately mount implant cases with inadequate posterior support for diagnosis and treatment planning. This technique of interocclusal registration has the advantages of accurate mounting, preservation of materials and financial expenses, and reduction of chair-side time. This appliance may also be used in all cases of multiple missing posterior teeth requiring prosthodontic treatment. Keywords: Interocclusal Records, Diagnosis and Treatment Plan, Implant Restorations

The use of a customized mounting guide for Implant-Prosthetic Restoration of the Fully Edentulous Arch

Reconstruction of fully edentulous arches with implant-retained dentures requires thorough planning and precise registration of the interocclusal relationship, to achieve a successful treatment outcome.