Deep Margin Elevation: Current Concepts and Clinical Considerations: A Review

Influence of proximal box elevation on microleakage in 3Y-TZP zirconia ceramic fixed dental prostheses after thermomechanical loading: A laboratory study

STATEMENT OF PROBLEM

Deep subgingival defects at the abutment teeth for fixed dental prostheses (FDPs) are a common problem in prosthodontics. Surgical crown lengthening or orthodontic extrusion of the abutment teeth have been recommended treatment options. However, disadvantages such as extended treatment time, treatment costs, or surgical problems have to be considered. Proximal box elevation has been proposed as an alternative, but microleakage studies are lacking.

PURPOSE

The purpose of this in vitro study was to investigate the influence of proximal box elevation (PBE) and conventional foundation restoration on the microleakage of 3 mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) ceramic FDPs after thermomechanical loading (TML).

MATERIAL AND METHODS

Sixteen molars and 48 premolars were divided into 4 groups (n=8). Either fixed-to-fixed (premolar, molar) or cantilever FDPs (premolar, premolar) were fabricated. The pontic of both groups had a mesiodistal width of 7 mm. The proximal foundation restorations were placed using a self-etch adhesive system and a dual-polymerizing composite resin, and a standardized tooth preparation design was carried out. All FDPs were adhesively luted and subjected to TML (1.2 million cycles, 5/55 °C, 49 N). After TML, all specimens were placed in fuchsin and then sectioned in a sagittal direction. The sections were evaluated with respect to the penetration depth of the dye by light microscopy at 4 different interfaces: tooth and luting composite resin (TC), luting composite resin and restoration (CR), tooth and foundation restoration (TB), foundation restoration and luting composite resin (BC). As data were not normally distributed, nonparametric tests were used for statistical analysis (α=.05).

RESULTS

Statistically significant differences were observed between the PBE and the control group (P<.05). Microleakage at the TB interface was detectable in all specimens of the PBE group, while 84.4% of the specimens of the control group showed leakage at the TC and TB interfaces. Leakage was detected at the CR interface in 3.1% of all specimens. No leakage was observed at the interface BC. Additionally, statistically significant differences were found within the same study specimen between the control (conventional foundation restoration) and the study side (PBE) (P<.05).

CONCLUSIONS

Irrespective of the pretreatment (experimental PBE or conventional foundation restoration), the adhesive bond of the foundation restoration and the luting composite resin to the dentin represented a limiting factor with regard to microleakage in fixed-to-fixed and cantilever FDPs. PBE was more frequently affected by microleakage than a conventional foundation restoration.

Deep margin elevation in anterior teeth: A clinical report

Subgingival fractures in the anterior region present challenges for adhesive ceramic restorations. The deep margin elevation (DME) technique, using composite resin to elevate subgingival margins before indirect restoration preparation, has been reported to improve outcomes while maintaining esthetic and functional integrity. Developed for posterior teeth, DME aligns with minimally invasive principles and leverages adhesive material advancements. Its use in anterior teeth preserves gingival architecture, supports periodontal health, and ensures precise adhesive protocols, essential for successful rehabilitation. This report outlines DME's systematic application for managing anterior subgingival fractures.

YouTube as an information source in deep margin elevation: Reliability, accuracy and quality analysis

The objective of this research was to assess the accuracy, quality, content, and demographics of videos on YouTube concerning deep margin elevation (DME). Initially, 100 videos for each of the three keywords were analyzed. The content categories of these videos were diverse, encompassing educational materials, teaching techniques, advertisements, and other types of content. The evaluation of the videos was carried out based on the Global Quality Scale (GQS), the Journal of the American Medical Association (JAMA) benchmark, and the modified-DISCERN questionnaire (m-DISCERN). Non-distributed data were analyzed using the Kruskal Wallis test and the Spearman correlation coefficient. The JAMA score was 1 for four videos, 2-3 for 38, and 4 for 14 videos; the GQS score was 1-2 for 18 videos, 3 for 11 videos, and 4-5 for 27 videos; and the m-DISCERN score was < 3 for 39 videos, 3 for four videos, and > 3 for 13 (for a total of 56 videos). Statistically significant differences were observed only for the JAMA scores when comparing the video source groups (p = 0.001). There were significant positive correlations between the GQS and m-DISCERN and m-DISCERN and JAMA scores (p < 0.001 and p = 0.049, respectively). The findings indicated that YouTube videos related to DME generally exhibited high-quality content but only moderate accuracy and poor reliability.

Impact of Thermal Aging on Marginal Adaptation in Lithium Disilicate CAD/CAM Crowns with Deep Proximal Box Elevation

BACKGROUND This computer-aided design and computer-aided manufacturing (CAD/CAM) study aimed to evaluate the effects of thermocycling on deep margin elevation relocation of subgingival cavity outlines in 80 molar teeth using advanced lithium disilicate ceramic. MATERIAL AND METHODS Eighty mandibular molar teeth were prepared for deep margin elevation below the cementoenamel junction. The following types of restorations were subsequently applied to each group: glass ionomer filling, bulk-fill flowable resin composite, bioactive resin composite, and nanohybrid resin composite. Full-coverage crowns with standardized preparation and a shoulder finish line were prepared to receive CAD/CAM-milled advanced lithium disilicate crowns. Samples were examined at 6 equidistant points via digital microscope on each proximal surface at the restoration-tooth and crown-restoration interfaces before and after thermocycling for 15 000 cycles. Data were analyzed using one-way analysis of variance, at a level of significance of 0.05. RESULTS The vertical marginal gap was significantly higher after aging and was the highest for glass ionomer filling, 9.091 (±1.147) and 9.936 (±6.376) µm, followed by nanohybrid resin composite, 3.59 (±1.03) and 3.87 (±0.97) µm, bioactive resin composite, 3.17 (±0.81) and 2.59 (±0.21) µm, and bulk-fill flowable resin composite, 1.89 (±0.60) and 2.42 (±0.64) µm, at the cervical and apical interfaces, respectively. CONCLUSIONS Thermocycling significantly changed the marginal adaptation of all restorative materials. Highest values for marginal adaptation were recorded in the glass ionomer filling group, followed by nanohybrid composite and bioactive resin groups, whereas lowest values were recorded among the bulk-fill flowable resin composite group at cervical and apical interfaces.

Enhancing subgingival margin restoration: a comprehensive review and meta-analysis of deep margin elevation's impact on microleakage

INTRODUCTION

Restorative dentistry faces complex challenges with deep proximal surface destruction, requiring novel approaches like DME (Deep Margin Elevation). In order to achieve the best results while treating severe tooth damage, this study examines the advantages, disadvantages, and possible collaborations of different treatments.

AIMS

This systematic review investigates the efficacy of DME as an adjunctive procedure in restorative dentistry, specifically focusing on its impact on microleakage.

METHODS

The study adheres to PRISMA guidelines and employs the PICOS framework for eligibility criteria. 394 potentially qualifying studies were discovered and thorough literature search was carried out via databases. After applying inclusion criteria, 7 studies were included in the analysis. Articles were selected based on criteria that included indirect restoration and performing DME and were compared with indirect restorations without DME. Composite resin was used for DME. Other materials for DME performing, including GI and composite flow, were systematically reviewed. Data analysis was done by biostat software (α = 0.05).

RESULTS

The meta-analysis of selected studies reveals a statistically significant positive effect of DME on reduction of microleakage (p = 0.001).

CONCLUSION

The results of this study underscore the potential of DME in addressing subgingival margin challenges and provide valuable insights for restorative dentistry practices.

Deep margin elevation in restorative dentistry: A scoping review

OBJECTIVES

Deep margin elevation (DME) is a restorative approach offering the possibility of performing stepwise elevation of deep proximal cavities to create more favourable margins for direct or indirect restorations. The objectives of this scoping review were to explore what is known or unknown about DME by describing a wide ranging evidence base including peer reviewed literature and non-traditionally published information on the web.

DATA

Data were extracted from the included evidence in order to describe the following: the extent and nature of the evidence base; the situations which are appropriate for DME; the materials and techniques which are used; the outcomes which have been measured in empirical studies; the risks which have been reported; and the findings which have been reported in studies which compared DME to surgical crown lengthening.

SOURCES

This scoping review included a wide range of published evidence and extensive web searching for grey literature, including CPD, training and multimedia information.

STUDY SELECTION

The findings revealed a range of published literature as well as freely available, online information advising practitioners about DME. Most empirical evidence was based on in vitro studies, and there were few clinical studies comparing DME to crown lengthening. Online information included recent, multimedia sources.

CONCLUSIONS

DME is a technique that can be used with motivated patients with good oral hygiene if rubber dam isolation is achieved, if there is no invasion of the connective tissue space, and if a strict restorative protocol is adhered to.

CLINICAL SIGNIFICANCE

With phasing out of amalgam and adhesive dentistry increasing in popularity, DME addresses multiple clinical problems associated with sub-gingival margins prior to restoration.

Soft Tissue Retraction Maneuver in Cone Beam Computed Tomography Prior to Crown-Lengthening Procedure-A Technical Note

Background: An accurate determination of the biological width and the relationship of the cemento-enamel junction with the border of the alveolar bone is crucial during a clinical crown-lengthening (CCL) procedure. The aim of this study was to present a technical note about the retraction techniques in cone beam computed tomography (CBCT) prior to CCL, highlighting the significant enhancement in procedural accuracy and predictability that these techniques offer. Methods: Clinical and radiological examinations should be performed before a CCL procedure. It is necessary to determine the length of the tooth crowns, the periodontal pockets' depth, and the phenotype of the gingiva. The ideal CBCT examination should be performed with soft tissue retraction. This can be achieved using retractors or cotton rolls. Results: Retraction of the lips, cheeks, and tongue allows one to assess the marginal gingiva, the cemento-enamel junction, and the alveolar bone. A detailed plan of the CCL procedure, which involves retraction, ensures both the aesthetic appeal and the achievement of a newly defined gingival zenith, enhancing the overall visual harmony. Conclusions: Compared with conventional radiographic imaging, the soft tissue retraction maneuver in CBCT prior to CCL surgery offers an effective approach to the evaluation and diagnosis of soft and hard tissue. This is because of the detailed planning of the aesthetic CCL procedure. Such an approach leads to superior aesthetic outcomes in dentistry, contributing to the advancement of aesthetic dentistry through a harmonious blend of art and science.

Polishing methods for composites restoration: the influence on human gingival fibroblasts behaviour

BACKGROUND

Carious/Non-carious cervical lesions with gingival recessions may require both dental and periodontal reconstructive therapy, where flaps/grafts may be placed in contact with a dental filling material. Human Gingival Fibroblasts (HGF-1) response during the early phase of healing could vary according to the procedures employed to cure the dental composite. Moreover, oxygen diffusion into dental composite inhibits the polymerization reaction, creating an oxygen-inhibited layer (OIL) that presents residual unreacted monomers. The aim of this study was to assess the effect of different polishing techniques and OIL on HGF-1.

METHODS

Composite discs polished with different techniques (diamond rubber, abrasive discs and tungsten carbide burr) were used. An additional not polished smooth group obtained with and without OIL was used as control. Samples were physically characterized through the analysis of their hydrophilicity and surface topography through contact angle measurement and SEM, respectively; afterwards the biologic response of HGF-1 when cultured on the different substrates was analyzed in terms of cytotoxicity and gene expression.

RESULTS

The finishing systems caused alterations to the wettability, even if without a proportional relation towards the results of the proliferation essay, from which emerges a greater proliferation on surfaces polished with one-step diamond rubber and with abrasive discs as well as a direct effect of the glycerin layer, confirming that surface roughness can heavily influence the biological response of HGF-1.

CONCLUSIONS

Surfaces wettability as well as cellular behavior seem to be affected by the selection of the finishing system used to lastly shape the restoration. Especially, the presence of OIL act as a negative factor in the regards of human gingival fibroblasts. The present study may provide the first clinical instruction regarding the best polishing system of composite material when the restoration is placed directly in contact with soft tissue cells. Understanding HGF-1 behavior can help identifying the polishing treatment for direct restoration of carious/non-carious cervical lesions associated with gingival recessions.

Identification, Evaluation, and Correction of Supracrestal Tissue Attachment (Previously Biologic Width) Violation: A Case Presentation With Literature Review

The supracrestal tissue attachment (SCTA) is the new terminology for biologic width. SCTA is defined as the physiologic dimension of a solitary functional unit composed of junctional epithelium and connective tissue attachment. Its preservation is critical for the well-being of periodontal health. SCTA has been widely studied and scientific literature is indicative of its significance during the placement of restoration, including prosthetic crowns. This should be taken care of in cases of anterior teeth within the smile zone, where dental crowns are regularly placed subgingivally for aesthetic reasons. In addition, any violation of SCTA while restoring the dentition will present as gingival inflammation and pain, consequently, leading to failure of the clinical procedure.

Structurally compromised teeth. Part I: Clinical considerations and novel classification proposal

OBJECTIVE

A comprehensive classification of structurally compromised teeth (SCT) was introduced.

CLINICAL CONSIDERATIONS

Dental injuries or operative mismanagement undermine the structural integrity of the tooth abutment, reducing its biomechanical strength and rendering restorative procedures challenging. To standardize the overall pre-operative evaluations and determine the biological and mechanical features, a classification of the coronal and cervical tooth defects, as well as an attentive analysis of the most apical location of the residual cervical tooth structure along the whole perimeter and the most coronal location of the bucco/lingual residual structure was presented. Considering the residual cervical structure, five possible clinical scenarios were individuated with respect to the gingival margin, gingival sulcus, supracrestal tissue attachment and bone crest (BC). The latter prevents the isolation procedures rendering the adhesive restorations unfeasible. Instead, the location of the most apical portion of residual cervical structure within subgingival/intrasulcular depth (>1.5 mm above BC) can be considered restorable.

CONCLUSIONS

This classification is threefold: to enclose all the possible clinically encountered tooth defects, to identify the apical problems of SCT to appropriately manage the perio-restorative interfaces, and to evaluate the tooth resistance capacity of SCT, as to plan and perform the most adequate biomechanical restorative approach.

CLINICAL SIGNIFICANCE

The present classification is proposed to provide a complete perspective of structurally compromised teeth to standardize the biologic and biomechanical evaluations during planning of restorative procedures.

Relationship between Deep Marginal Elevation and Periodontal Parameters: A Systematic Review

Background and Objectives: This review focuses on reviewing studies from the literature regarding the effects of deep margin elevation on the surrounding periodontium. Materials and Methods: A review of the literature was carried out using the following online databases: Embase, The Cochrane Library, MEDLINE-PubMed and Google Scholar. Our search was limited to articles from 2010 to 2023. The search terms consisted of keywords and MeSH terms, which were 'deep margin elevation', 'coronal margin relocation', 'periodontium' and 'periodontal tissues'. The literature was searched thoroughly by two reviewers. Initially, the titles of the articles were extracted. After removing irrelevant and duplicate articles, abstracts were assessed for relevant articles. Finally, the reviewers analyzed full-text articles. Results: A total of twelve articles, including one randomized clinical trial, three systematic reviews, two prospective cohort, three case series, one a clinical study, one pilot study and one a retrospective study, were selected and analyzed. Conclusions: The review suggests potential benefits of Deep Margin Elevation (DME) over surgical crown lengthening due to reduced invasiveness, yet conclusive effects on periodontal tissue remain unclear, warranting further studies on clinical parameters and inflammatory biomarkers.