Interproximal Contact Research Articles

Risk factors contributing to interproximal contact loss between an implant crown and a natural tooth.

Interproximal contact loss (ICL) is considered a prevalent complication for a tooth abutting an implant restoration. While numerous potential causes for ICL have been presented, there is no consensus. A review of the current literature with a focus on possible risk factors was performed. A PubMed search using keywords "implant OR dental implants OR implant supported prosthesis AND proximal contact loss OR ICL OR loss of interproximal contact OR open contact OR interproximal open contact OR adjacent natural teeth" resulted in 81 citations, 9 of which were relevant to the focus question. Additional references were culled from the reference lists in the identified articles. Systematic reviews, case series, and case reports were reviewed with a focus on causation, association, or correlation. Eight systematic reviews and 14 case series were reviewed. The prevalence of ICL has been reported to be as low as 16% and as high as 66%. ICL was more common on the mesial side of implants and when a tooth abuts a splinted implant restoration. The absence of a uniform definition to accurately describe an interproximal (IP) contact and an open IP contact is demonstrated in the literature. A lack of standardized measurement strategies that relate to a needed consensus definition further exacerbates the broad range of reported results regarding ICL. The lack of controls for almost all the ICL literature makes it difficult to draw conclusions and comparisons to unrestored, natural tooth IP contacts and the prevalence of ICL in this patient population. As a result, the available studies are inadequate to support a causal theory and the potential risk factors associated with ICL. There is a large range of reported prevalence for IP contact loss. ICL is more common when a natural tooth abutsa splinted implant restoration. ICL is more common on the mesial, as opposed to the distal, of an implant retained restoration. Consensus in the definition and measurement strategies for ICL needs to be established to provide standardized terminology and methodology. Potential risk factors such as occlusion, restorative material, and tooth contact area need to be investigated.

A novel coded healing abutment for a simplified digital workflow: A retrospective clinical study on 103 patients with a one year follow-up

ObjectivesTo present the clinical results obtained using a novel coded healing abutment (CHA). MethodsWe evaluated 103 patients with fixed implant-supported zirconia restorations (90 single crowns, 26 partial dentures, and 6 full arches) manufactured via computer-aided-design/computer-assisted-manufacturing and starting from the point of intraoral scans of novel CHAs (i-Physio®, LYRA-ETK, Sallanches, France). Patients were followed for one year. We assessed the clinical precision of the final restorations at delivery (quality, fit, and occlusal and interproximal contacts), as well as hard and soft tissues stability and patient satisfaction at the one-year follow-up. All complications were recorded. ResultsThe quality of the restorations was high, with satisfactory marginal fits (96.8% of the cases), occlusal contacts (95.1%), and interproximal contacts (94.3%). Excellent hard and soft tissues stability were found at the one-year follow-up assessment, with few complications (0.9% biological, 4.9% mechanical, and 1.6% technical) for an overall restoration success rate of 92.3% at the patient level and 91.9% at the restoration level. Patient satisfaction was high. ConclusionsWithin the limits of this study (retrospective design, short follow-up time) this novel CHA, with high prosthetic precision and esthetics, was clinically reliable and promoted hard and soft tissue stability. Further studies on a larger sample of patients and a longer follow-up period are needed to confirm these preliminary clinical outcomes. Clinical relevanceHigh prosthetic precision can be achieved when scanning CHAs. CHAs simplify digital impressions, reduce the manipulation of soft tissues, and prepare them for scanning, thereby promoting tissue healing and stability over time. Additionally, CHAs can serve as temporary abutments for immediate, nonfunctional loading.

3D-Printed Permanent Resin Crowns on Pre-Molar and Molar Teeth; Two-Year Results of a Prospective Clinical Study.

The aim of this prospective clinical study was to evaluate the 12 and 24-month clinical results of overlay and one-piece endodontic crown restorations applied with additively manufactured 3D printed permanent ceramic-filled resin (PCR) according to the Modified US Public Health Service (USPHS) criteria. A total of 33 indirect restorations (16 overlay, 17 endocrown) (4 premolar, 29 molar) produced using PCR (Formlabs) were applied to 30 patients by a single dentist. The restorations were evaluated according to the modified USPHS criteria at baseline (7 days), 12 and 24 months times by two independent evaluators. The study registration number is NCT05168852. In the comparisons of the dependent criteria scores, the Related Samples Cochran Q test was used, and in post-hoc paired comparisons, the Bonferroni test. The Fisher-Freeman-Halton test was applied in the comparisons of categorical variables according to the restoration type groups (α = 0.05). No statistically significant difference was determined between the evaluation criteria scores at baseline, 12 months, and 24 months for the marginal adaptation (P=0.05), retention (P=1), interproximal contact (P=0.368), color match (P=1), surface texture (P=1), and patient satisfaction (P=1). The only score criteria that showed a statistically significant difference between baseline and 24 months (P=0.001) among all other criteria was marginal discoloration. This criteria's score change was from 100% A score to 69.7% A score. In the 2-year follow-up of indirect single-tooth restorations produced with 3D-printed PCR, all restorations showed acceptable clinical performance. (≥99.5%A+B score at 2 years).

An evaluation of occlusal changes during orthodontic retention

The problem of orthodontic relapse is of fundamental importance for clinicians. In the literature there are few studies concerning the change in position of the teeth after orthodontic treatment. This study analyzes the occlusal changes during the first six months of orthodontic retention and the effectiveness of the Hawley retainer at the upper arch and the canine-to-canine multi-stranded fixed retainer at the lower arch in maintaining the anterior tooth alignment. 48 patients were recruited. PAR index, ABO DI, ABO CRE, Irregularity Index, intercanine, interpremolar and intermolar widths were measured for each patient before (T0) and at the end (T1) of the fixed orthodontic treatment and after 1 (T2), 3 (T3) and 6 (T4) months of retention. Statistics used were paired samples t-test and Wilcoxon matched-pairs signed-ranks test. The p-value was considered statistically significant for P<0.05. During 6 months in retention there was a worsening of PAR index (mean: 1.13±1.08; P<0.001), dental alignment (median: 2.5; P=0.0001) and occlusal relationships (median: 2; P=0.0101); a statistically significant improvement of posterior occlusal contacts (median: 2.54; P=0.0004), marginal ridges (median: 0.5; P=0.0250) and interproximal contacts (median: 0.46; P=0.0305). The stability of the orthodontic results has proved to be similar for the two dental arches, as well as the effectiveness of the two retainers in maintaining the alignment of the anterior teeth. During 6 months in retention the occlusal changes were minimal and didn’t affect the stability of the orthodontic treatment in a clinically significant manner. The effectiveness of the upper Hawley retainer and the lower multi-stranded fixed retainer in maintaining the alignment of the anterior teeth was similar.

Modified OXIS Classification of Interproximal Contacts of Primary Canines and Its Prevalence in Six-to-Nine-Year-Olds in the Delhi National Capital Region: A Cross-Sectional Study.

The modified OXIS (O - open contact, X - point contact, I - straight contact, S - curved contact) classification provides a useful framework for assessing interproximal contacts in primary canines and predicting caries risk. The study aimed to assess the incidence of modified OXIS classification of canine interproximal contacts in six-to-nine-year-old children from the Delhi National Capital Region (NCR) population. A cross-sectional study was conducted to assess the interproximal contact areas between primary canine and first molar among six-to-nine-year-old children (n=400) according to the modified OXIS classification using the die stone study model. A single calibrated examiner performed a type III examination to assess a total of 1,536 contact areas from the occlusal aspect. The prevalence of each type was reported in terms of both numbers and percentages using the Chi-square test to find the prevalence, Fisher's exact test to compare the inter- and intra-arch occurrence of the different contact types, and Kruskal-Wallis test to find its correlation with age. The Chi-square test showed that the most common contact type was I at 46.55% (715), followed by S1 at 28.06% (431), X at 18.56% (285), O at 6.19% (95), and S2 at 0.65% (10). The p-value of 0.000 indicated a statistically significant difference among the groups. The Kruskal-Wallis test found no statistically significant differences in patient ages. Additionally, Fisher's exact test demonstrated a statistically significant prevalence of types O, I, and S1 when comparing them across arches. Based on the current study, the most common contact type observed was type I, followed by type S1, according to the modified OXIS criteria. The findings indicate a higher prevalence of closed-type contacts in this population, suggesting that the occurrence of such contacts increases as permanent teeth erupt. This tool may be useful for assessing caries risk in this age group.

Multidisciplinary Consideration for Managing Gingival Black Triangles in Aesthetic Dentistry: A Review

The importance of aesthetics in modern dentistry is paramount. Aesthetics has its different values and perceptions, which may be different from the eyes of the patient and those of the clinician [1]. It is dependent on the socio-economic status and the upbringing and mentality of each individual person. Open gingival embrasures or black triangle cause complex functional and aesthetic problems. Management of such problems requires careful evaluation of the underlying causes. In today’s aesthetic environment where both the dentist and the patient are aware of aesthetic value, the real challenge was to reconstruct this lost papilla and moreover to obtain stable and sustainable results. asure area, root angulations, interproximal contact position, triangular-shaped crowns and aging. Treatment of black triangles often requires an interdisciplinary approach, involving of periodontal; orthodontic and restorative treatment. In this review, the authors highlighted the important etiological factors that predispose to the occurrence of the black triangles. In addition to the common biological factors, dimensional changes of papilla during orthodontic alignment, the relevant consequences of periodontal disease treatment and iatrogenic treatment mishaps such as poor veneers and crowns are factors have also been discussed as factors that may lead to black triangles.

Prevalence of Decay and Tooth Condition Changes Adjacent to Restored Dental Implants: A Retrospective Radiographic Study.

This study examined the association between a dental implant and changes in adjacent teeth over time. Electronic health records of 1818 patients who received a dental implant were retrospectively evaluated over 14 years (2005-2019) in a university setting. The status of the adjacent tooth and vertical and horizontal distance from the implant platform to adjacent teeth were determined using digital intraoral radiographs taken at baseline and the last follow-up visit (1-14 years, median 4 years). In total, 1085 dental implants were evaluated. There were 234 instances of a change in the adjacent tooth. Decay was observed in 83 (7.6%) of adjacent teeth; the mean time to development was 4 years (range 1-14 years). Approximately 9% of adjacent teeth received direct restorations, 4.8% received indirect restorations, 1% received endodontic root canal treatment, and 5.6% were extracted. The mean horizontal distance between the implant platform and the adjacent teeth was 3.56 mm; the mean vertical distance from the contact point to the alveolar crest on the tooth side was 6.2 mm at the first time of the reported decay on X ray. These distances did not significantly influence the occurrence of caries. The prevalence of interproximal contact loss was higher on the mesial of the implant crown at 63% compared with 20% on the distal side. This large retrospective analysis identified that teeth adjacent to a dental implant were at risk of decay and changes in their condition. In addition, the implant-to-tooth distance and inadequate emergence profile may contribute as caries risk factors in addition to hygiene and a high sugar level diet. These findings appear essential for clinicians when making treatment decisions and discussing outcomes with patients.

A case report on the management of mandibular midline diastema by using laser as a treatment modality

A frenum is a fold of mucous membrane that connects the labial mucosa (lips) to the gingiva or that connects the tongue to the floor of the mouth and hence providing support to the lips and the tongue. The normal frenal attachment is at the level of mucogingival junction (mucosal) and hence maintaining a balance between the interproximal contacts of the anterior teeth of either maxilla or mandible. But if this frenal attachment is high or in other words if there is a an aberrant frenum, then this type of frenal attachment either results in spacing between the anterior teeth or in some cases can lead to the loss of gingival embrasure resulting in the creation of black triangle between the anterior teeth. Present case report is on a 38 years old female whose chief complaint was spacing between the mandibular central incisors and upon intraoral examination, it was noted that there was an aberrant frenum which has also resulted in loss of gingival embrasure between the mandibular anterior teeth and hence this aberrant frenum was treated by a process called frenectomy by using a thermal treatment modality called as Laser. Upon follow up after 1 week, there was a reduction in spacing between mandibular central incisors.

Comparative study on tribological behaviors of interproximal tooth enamel against zirconia under fretting and sliding conditions

Interproximal contact loss (ICL) between zirconia crown and adjacent natural teeth is a common complication that could lead food impaction and compromise the periodontal/peri-implant tissue health and patient’s satisfaction. Both fretting and sliding wear mode can be found in the frictional pair between zirconia crown and interproximal enamel during mastication. In this study, fretting and sliding wear behavior of interproximal enamel against zirconia in artificial silva was investigated. The wear damage of the interproximal enamel in a sliding movement was higher than in a fretting movement. In fretting mode, the running condition fretting map (RCFM) composed of partial slip regime (PSR), gross slip regime (GSR), and mixed fretting regime (MFR) was constructed depending on different normal loads and displacement amplitudes. Intact surface was observed in the PSR. Plastic deformation at contact center and microcracks at contact margin were detected in the MSR. Severe wear damage occurred in the GSR, predominated by microfracture, brittle deformation. Macroparticles generation, fatigue delamination and abrasive wear prevailed in sliding mode. In contrast, enamel debris could be transferred on zirconia surface while the material loss of the antagonist zirconia was negligible in both fretting and sliding test.

Prevalence of different types of interproximal contacts in the permanent dentition – a study cast evaluation

Background A new classification called OXIS was proposed for categorizing the interproximal contacts of primary molars, modified for the primary canines and its prevalence was established. No such information is available for the permanent dentition. Hence, the aim was to establish the variations in interproximal contacts of the permanent dentition and thereby modify the OXIS classification of primary molars and primary canines to the permanent dentition. Methods We propose a study-cast-based classification of interproximal contacts of the permanent dentition. Three hundred and forty-three pretreatment casts of patients based on an inclusion and exclusion criteria were selected. Contacts of posterior teeth were classified based on OXIS classification of interproximal contacts, and its modification was used for anterior teeth. Results Among the posterior contacts, the ‘O’ type of contact was least prevalent, while most prevalent was the ‘S’ type for second molar-first molar contact, ‘I’ type for the first molar-second premolar contact, and ‘X’ type for the second premolar-first premolar contact. Among the anterior contacts, least prevalent was ‘S1’ type for the first premolar-canine contact, and I type for the canine-lateral incisor and the lateral incisor-central incisor contacts. There was no statistical significance between right- and left-side contacts (P > 0.05) while significance was seen between maxillary and mandibular contacts (P < 0.05). Similarity of contacts ranged from 5.17% to 10.05%. Conclusion The OXIS classification is applicable to posterior permanent teeth, and its modification is representative of anterior permanent teeth.

Development of 'OXIS Classification' calibration website for dental researchers.

The variations in interproximal contact areas have been categorised open (O), point (X), straight (I), and curved contact (S). This is based on their shapes and termed as OXIS classification. The interactive OXIS calibration website was developed to assist researchers seeking appropriate knowledge, minimise the overload of material, optimise efficiency in calibration and, to provide repositories for clinicians, healthcare workers, and policymakers. The website was developed in two phases. The first phase of development included expert group discussion, Focus Group Discussion (FGD), and the implementation of FGD recommendations. The second phase emphasised registration and development of the interactive web portal on OXIS classification. The developed website was subjected to user experience testing, functional testing, performance testing, security testing, device, platform testing, and then hosted. Calibrated students and faculties evaluated it with the help of Suitability Assessment of Materials (SAM) and System Usability Scale (SUS). Finally, after amendments, the website was evaluated by non-calibrated researchers and multidisciplinary experts. The total agreement was 74% for overall SAM category. Pooled mean total score of SUS was 52.7 (SD 7.17; range 45-67.5), indicating an average score. The content of the developed website has been evaluated as "satisfactory" and its technical quality as "of higher standards".

Comparative Evaluation of Polymethyl Methacrylate and Thermoforming Crowns as Semipermanent Crowns in Primary Molars: An In Vivo Study.

The present randomized clinical trial is aimed at evaluating clinical efficiency of two different types of esthetic crowns-polymethyl methacrylate crowns and vacuum formed thermoformed crown as an alternative to full-coverage coronal restoration for deciduous molars. A total of 45 primary molars in pediatric patients were selected using randomization and split into three groups based on the technique used for preparation of crowns: group I-polymethyl methacrylate crowns; group II-thermoformed crown; and group III-stainless steel crowns (SSC). All crowns were clinically and radiographically evaluated at baseline, 1st month, and 3rd month for gingival health, retention, marginal integrity, proximal contacts, occlusion, alignment, and staining. The data was tabulated and analyzed by Statistical Package for the Social Sciences (SPSS) Version 23.0 software. The intergroup comparison was done by Kruskal-Wallis test, analysis of variance (ANOVA), and Mann-Whitney U test for continuous data. The intragroup comparison was done by Friedman test and Wilcoxon signed-rank test for categorical data. All p-values < 0.05 were considered statistically significant. With regard to the parameters of plaque score, gingival index score, occlusion, interproximal contacts, retention, alignment, and marginal adaptation, no statistical significance was noted between the three groups. However, with regard to the discoloration (staining) when the polymethyl methacrylate acrylic (PMMA) group was compared with thermoforming group, statistical significance was noted in 1st month with p-values of 0.04 and 0.03, respectively. On intragroup comparison, statistically significant values were obtained in SSC group for plaque score and thermoforming group for gingival index score. The study concluded that the PMMA and thermoforming crowns can be used as an alternative to SSC for restoring the primary molars as they showed equivalent results to that of standard SSC. Matha N, Kumar KS, Reddy BVT, et al. Comparative Evaluation of Polymethyl Methacrylate and Thermoforming Crowns as Semipermanent Crowns in Primary Molars: An In Vivo Study. Int J Clin Pediatr Dent 2024;17(S-1):S43-S54.

Clinical Effects of Interproximal Contact Loss between Teeth and Implant-Supported Prostheses: Systematic Review and Meta-Analysis

Clinical Effects of Interproximal Contact Loss between Teeth and Implant-Supported Prostheses: Systematic Review and Meta-Analysis

Evaluating the tightness of proximal contact between natural tooth and adjacent implant supported prosthesis.

The changes in interproximal contact between implant supported prosthesis (ISP) and adjacent natural tooth is of interest to dentists. Hence, we evaluated the tightness of proximal contact (PCT) between adjacent natural tooth and ISP by applying a digital force gauge spanning over a period of 1.5 year with a regular follow-up of 3, 6, and 12 months.80 patients who received ISP were included in this study. In order to measure the PCT, every patient seated in the identical upright position in the dentist chair. The digital force gauge was used to take measurements for mesial PCT and distal PCT. The mesial as well as distal interproximal contacts was more tight as in case of natural tooth adjacent to other natural tooth as compared to interproximal contacts between ISP and adjacent natural tooth. It was also observed that as the time progressed there was decrease in PCT values in both categories. After 12 month follow up 30.6% cases in category 2 while 21.2% cases in category 1 showed complete loss of interproximal contact. There is significant change in proximal contact tightness in interproximal area between implant supported prosthesis and adjacent natural tooth over a period of time and necessary measures should be taken to prevent or reduce it.

Three dimensionally printed template with an interproximal isolation design guide consecutive closure of multiple diastema with injectable resin composite.

This article describes a novel 3D-printed template armed with interproximal matrices to isolate interproximal contact areas and guide injectable resin composite for consecutive closure of multiple diastema. Among several treatment options proposed for diastema closure, direct resin composite is noninvasive and easy to repair. The "composite injection technique" has been introduced to improve time efficiency and reduce technique sensitivity for clinicians. However, in the case of multiple diastema, the overflow of excess resin materials onto the adjacent teeth during injection poses challenges for recontouring the interproximal anatomy. A 3D-printed template with special-designed gaps at interproximal areas was designed and fabricated based on a virtual diagnostic wax-up. Flowable resin composite was then consecutively injected through the template to close diastemata at multiple adjacent teeth. This technique using a 3D-printed template with interproximal isolation design contributed to an efficient and accurate operation for multiple anterior diastema closure. Efficient and accurate freehand buildups of composite restoration for multiple diastema are challenging in operative dentistry. The described noninvasive full digital workflow provides a predictable method to accurately recontour the multiple target restorations and reduce the chair-side time and technical sensitivity.

3D-printed short-span hybrid composite implant-supported restorations fabricated through tilting stereolithography: A retrospective clinical study on 85 patients with 1 year of follow-up

PurposeTo report the clinical results obtained with fixed short-span (single crowns [SCs] and fixed partial prostheses [FPPs]) implant-supported hybrid composite restorations fabricated through tilting stereolithography (TSLA). MethodsThis retrospective clinical study included 85 patients who had been restored with 95 fixed short-span implant-supported hybrid composite (Irix Max®, DWS Systems) restorations (70 SCs and 25 FPPs up to three units) fabricated with TSLA. The full-digital model-free workflow was based on intraoral implant scanning, computer-assisted design (CAD) and 3D printing using TSLA (Dfab®, DWS Systems). The primary outcomes were the marginal adaptation, the quality of the occlusal and interproximal contact points, and the chromatic integration of the restorations, assessed independently by two experienced operators (a prosthodontist and a periodontist). A score from 1 to 5 (with 5 as the highest value, 4 for satisfactory quality, 3 for acceptable quality, and 2 and 1 as the lowest values, expressing unsatisfactory quality) was assigned by each operator to each restoration at delivery. The secondary outcomes were the survival and success of the restorations at the 1-year follow-up. The restoration was defined as successful in the absence of any complications throughout the follow-up period. A statistical analysis was conducted. ResultsFor the quality of the marginal closure and occlusal and interproximal contact points, the 3D-printed hybrid composite restorations scored highly; the aesthetic integration was satisfactory. One year after placement, all restorations survived, with a low incidence (4.2 % overall, 5.7 % SCs) of complications (two abutment screw loosenings, two decementation of the restorations, and one upper portion of the hybrid abutment decemented from the titanium base), for a success rate of 95.8 %. ConclusionsWithin the limits of this study (retrospective design, follow-up limited to 1 year from the delivery, and only cemented restorations included) fixed short-span implant-supported hybrid composite crowns and bridges fabricated through TSLA were clinically precise, presenting a low incidence of complications at 1 year. Statement of clinical relevanceThe use of TSLA printing technology can open new perspectives for the treatment of small edentulous gaps with definitive implant-supported prosthetic restorations.

Digital workflow for prosthetic management of malpositioned implant in an adolescent patient: A 20-year follow-up.

Dental implants placed in adolescent patients pose a challenge to restore and maintain an esthetic outcome over longer period of follow-up. Maxillomandibular changes throughout adulthood may lead to complications such as implant infraocclusion and interproximal contact loss. This case report describes an alternate prosthetic treatment strategy for maxillary single implant placed in an adolescent patient in the esthetic zone with inappropriate implant axis and screw hole placement. With temporary restorations, the gingiva and soft tissues were shaped to imitate the emerging profile of the contralateral side. A zirconia screw-retained abutment was customized as a copy-mirror from the contralateral prepared tooth to mimic the exact shape and to avoid labiolingual over contour by computer-aided design/computer-assisted manufacture (CAD/CAM). The porcelain laminate veneer was bonded to the zirconia abutment. Porcelain adhesive approach was used instead of traditional principles of retention and resistance form of the abutment. A functional and esthetic outcome was achieved and maintained, while a minimally invasive procedure was implemented to use the malplaced implant instead of explanting it. The present report illustrates the prosthetic management of a malpositioned dental implant placed 20 years ago, utilizing a minimally invasive digital protocol.

Variation of OXIS contact areas in primary molars among 3-6-year-old children with intraoral digital scanning.

To determine the variation of OXIS contact areas in primary molars using digital impressions generated from an intraoral scanner (IOS). A cross-sectional study was carried out on 214 caries-free posterior quadrants of 80 children (38 males and 42 females) aged 3-6years. Calibration of taking digital impressions with the IOS procedure was performed initially through scanning of ten quadrants of children to provide a learning environment to the examiner. The digital impressions were then exported, and the type of interproximal contact areas present between the distal surface of the primary first molar and the mesial surface of the primary second molar were identified according to the OXIS classification. The prevalence of the types of OXIS contact areas was expressed in the form of numbers and percentages. The chi-square test was applied to investigate the variability among the arches and to understand the association of OXIS contact areas across age, gender, and arches. The most common contact area type observed was I-type (59.8%), followed by S-type (15.4%), X-type (12.6%), and O-type (12.2%). The I-type contact area was most frequently seen in both males (51.6%) and females (65.5%), while the S-type contact area in males (14.7%) and X-type contact area in females (8.4% each) were the least frequent with no statistical significance between genders (p > 0.05). All three age groups studied showed the highest prevalence of the I-type contact area, which increased with an increase in age (p < 0.05). The inter-arch comparison showed a significant result in terms of the X-type contact area on the right side, and O-type, X-type, and I-type contact areas on the left side, while no statistical difference was seen in the intra-arch comparison for all contact types. I-type contact areas were the most prevalent across the arches, age groups and genders.

Near-infrared imaging in orthodontic intraoral scanners for early interproximal caries detection

Intraoral scanners commonly used in orthodontic offices now offer near-infrared imaging (NIRI) technology, advertised as a screening tool to identify interproximal caries. This study aimed to evaluate the reliability and validity of NIRI detection of interproximal carious lesions in a common intraoral scanner (iTero Element 5D; Align Technology, San Jose, Calif) with and without bitewing radiograph complement, compared with a microcomputed tomography (micro-CT) reference standard. Extracted human posterior teeth (premolars and molars) were selected for early (noncavitated) interproximal carious lesions (n= 39) and sound control surfaces (n= 47). The teeth were scanned via micro-CT for evaluation by 2 blinded evaluators using consensus scoring. The teeth were mounted to simulate anatomic interproximal contacts and underwent a NIRI scan using iTero Element 5D and bitewing radiographs. Two trained, calibrated examiners independently evaluated (1) near-infrared images alone with clinical photograph, (2) bitewing radiograph alone with clinical photograph, and (3) near-infrared images with bitewing radiograph and clinical photograph in combination, after at least a 10-day washout period between each evaluation. Interrater reliability was highest for NIRI alone (k= 0.533) compared with bitewing radiograph alone (k= 0.176) or in combination (k= 0.256). NIRI alone showed high specificity (0.83-0.96) and moderate sensitivity (0.42-0.63) compared with a micro-CT reference standard. Dentin lesions were significantly more reliably detected than enamel lesions. After rigorous training and calibration, NIRI can be used with moderate reliability, high specificity, and moderate sensitivity to detect noncavitated interproximal carious lesions.

Three-dimensional evaluation of interproximal contacts of permanent dentition: a cone beam computed tomography study.

To assess the various patterns of the inter-proximal contact areas of the permanent dentition using the available cone beam computed tomography (CBCT) images. A retrospective cross-sectional study was performed on existing CBCT images from a University hospital and teaching department. Three thousand two hundred and fifty inter-proximal contacts were assessed from 125 existing CBCT scans of patients (age range: 14years 3months-29years 9months) who had matched the eligibility criteria. The types of inter-proximal contacts of the permanent dentition were scored at occlusal, middle, and cervical thirds, according to the OXIS inter-proximal contacts classification. Chi-square test was used to assess the contacts and gender/arches. The most prevalent contact was type I for the posterior teeth contacts, and types S1 and S2 for the anterior teeth contacts. Statistical significance was not observed between the contacts on the left and right sides (P > 0.05), while statistical significance was observed between the inter-proximal contacts of the maxilla and mandible (P < 0.05). The CBCT-based three-dimensional assessment of the inter-proximal contact areas of the permanent dentition is representative of the OXIS classification. The occlusal level contact was predominantly representative of the overall type of the contact.