Update on aesthetic coronoradicular reconstructions of posterior teeth

The restoration of teeth treated endodontically and having undergone significant loss of substance remains a challenge for dental surgeons. It represents one of the most frequent clinical sequences of general practice on a daily basis. This act is so common and so repetitive that the practitioner often performs it automatically, almost reflexively, applying the same mode of restoration to most clinical situations. Metal coronoradicular restorations (RCR) have long been considered the standard for restoring depulpated posterior teeth, as this type of restorations offer increased mechanical resistance to the occlusal stresses to which posterior teeth are subjected. The advent of adhesive dentistry has revolutionized the restoration of depulpated posterior teeth. It has become possible today to combine aesthetics, mechanical resistance and biocompatibility thanks to the fiber-based coronoradicular restoration of the posterior sector. In this article, we will detail the clinical protocol for an esthetic restoration of two premolars treated endodontically and severely damaged.

Adhesion to Enamel and Dentin: A Review

Bonding agents play a crucial role in the effective sealing and retention of resin-based composite restorations, which have been increasingly placed and replaced by dentists in many countries around the world. In fact, direct adhesive restoration with composite resins has become the procedure of choice for the treatment of anterior and posterior teeth. However, long-term durability of those restorations may be compromised due to progressive loss of the integrity of adhesive interfaces. This means that no adhesive strategy is free from technique sensitivity. The specificity and proportion of different constitutive molecules, the interaction between them and substrates can differ greatly from one class of adhesive system to another, which can affect bond quality. Protocol simplification has been an inevitable trend that has boosted the use of self-etching and universal systems in adhesive dentistry.

Reattachment of Crown in Anterior Fractured Tooth-A Case Report

In dentistry, traumatic injuries are most common in the anterior teeth due to its anatomic position. The various treatment modalities have been used depending on the extent of injury on teeth and supporting structures. Esthetic concerns are the most important challenges in modern dental practice. Adhesive dentistry is an excellent approach regarding esthetics, especially for fractured anterior teeth. This case report describes the successful treatment of reattachment procedure in a 17-year-old male patient presented with a fractured maxillary left central incisor.

Nanomechanical and molecular characterization of aging in dentinal collagen

Methylglyoxal (MGO) is an important molecule derived from glucose metabolism with the capacity of attaching to collagen and generating advanced glycation end-products (AGEs), which accumulate in tissues over time and are associated to aging and diseases. However, the accumulation of MGO-derived AGEs in dentin and their effect on the nanomechanical properties of dentinal collagen remain unknown. Thus, the aim of the present study was to quantify MGO-based AGEs in the organic matrix of human dentin as a function of age and associate these changes with alterations in the nanomechanical and ultrastructural properties of dentinal collagen. For this, twelve healthy teeth from <26 year-old and >50 year-old patients were collected and prepared to obtain crown and root dentin discs. Following demineralization, MGO-derived AGEs were quantified with a competitive ELISA assay. In addition, atomic force microscopy (AFM) nano-indentation was utilized to measure changes in elastic modulus in both peritubular (PT) and intertubular (IT) collagen fibrils. Finally, principal component analysis (PCA) was carried out to determine aging profiles for both crown and root dentin. Results showed increased presence of MGO AGEs in the organic matrix of dentin in the >50 year-old compared to <26 year-old samples in both crown and root. Furthermore, an overall increase in PT and IT collagen elasticity was observed in the >50 year-old group associated to ultrastructural changes in the organic matrix determined by AFM analysis. Furthermore, PCA loading plots suggested different 'aging profiles' in both crown and root dentin, which could potentially have important therapeutic implications in restorative and adhesive dentistry approaches. Overall, these results demonstrate that the organic matrix of human dentin undergoes aging-related changes due to MGO-derived AGEs with important changes in nanomechanical behavior of collagen that may impact diagnostic and restorative procedures in the elderly.

Deep Margin Elevation for Indirect Restorations: A Systematic Review

Background: The evolution of adhesive dentistry has increased the demand for improving the clinical outcomes of indirect restorations. There are several challenging factors in restoring teeth with deep interproximal lesions. Surgical crown lengthening has been the primary procedure to avoid violation of the biological width. In recent years, deep marginal elevation (DME) has been proposed as an alternative procedure for maintaining biological width in cases with subgingival defects. The aim of this review was to search for the best available evidence concerning the clinical outcomes of DME. Methodology: A comprehensive online search was performed using three different databases (using PubMed, the Cochrane Library, and the American dental association library for evidence-based dentistry). Four independent authors reviewed studies, collected data, and assessed the risk of bias. Results: The initial search revealed 1,763 studies. Duplicates were removed, and an extensive review was performed. Only six studies met the inclusion criteria and were accepted in the review. Conclusions: The systematic review advocates that DME is a reasonable, predictable, and reliable clinical procedure. There is a limitation of clinical studies in this field; therefore, more clinical studies with long-term follow-up periods are necessary.

Selection of adhesive systems in treatment of tooth root caries (literature review)

Adhesive dentistry is the foundation on the basis of which there have been global changes in the concept of adhesion of composite materials in therapeutic dentistry, protocols for fixing ceramic restorations in orthopedic dentistry. But a number of unsolved problems remained – the adhesion of composite materials to sclerosed dentin and tooth root cement, the sensitivity of the components of the adhesive systems to the wet environment of the oral cavity and spatial stability in the presence of dentinal fluid moving centrifugally in the dentinal tubules, the lack of restoration of periodontal attachment to the defect that occurs during tooth root caries. The review analyzes the results of studies on the use of self-etching adhesive systems in the treatment of root caries. The physician's ability to choose an adhesive system in a particular clinical case demonstrates his fundamental knowledge and minimizes the percentage of errors that he can make during the treatment phase.

The Next Big Thing is Really Big!! Magnification in Dentistry

BACKGROUND The advances in the magnification sector have revolutionised the endodontic treatment from tactile and radiograph based to the vision driven. Using magnification tools like loupes, microscopes, rod lens endoscopes and oroscopes in the endodontic practice enables the clinician to magnify the field of treatment further than that by naked eyes. Suitable illumination along with magnification adds to the success of any dental procedure. Dating back to 1870, surgical loupes have been used. Apotheker and Jako introduced microscope in dentistry for the first time in 1978. Carr, in 1992 highlighted the role of the surgical operating microscope in endodontics. Various applications of surgical operating microscopes include minimally invasive surgical techniques like in periodontal regenerative procedures, adhesive dentistry and various procedures in endodontics like caries detection, for hidden canals, pulp stone removal, instrument removal, surgical endodontics, retreatment, perforation seal etc. Parts of operating microscope include optical components, objective lens, binocular tubes, eyepieces, lighting unit and mounting system. Accessories include motorised / foot-controlled adjustment of focal length, mechanical optical rotating assembly (MORA) interface and beam splitter. Magnification aids assist in producing higher quality procedures due to better precision and accuracy. Using the microscope aids improved ergonomics for the operator. Using loupes or microscopes improves the clarity in treatment plan as well as its execution. The magnification aids with camera and video monitor attached, enhance the patient education and better documentation. A strong consideration should be given to adopt using the concept of magnification. This review intended to explain the use of these tools in dental procedures for better accuracy, handling and thoroughness, which will lead to fewer procedural errors. KEY WORDS Magnification, Illumination, Loupes

Reconciling Inherent Interfacial Compatibility Conflict Enhances Adhesive Infiltration and Resolves Dentin Bonding Durability

Wet bonding is a basic technique used daily in clinics for tooth-restoration fixation. However, only 50% of the bonding lasts more than 5 years and thus patients must visit the dentists repeatedly. This is attributed to the limited infiltration of adhesives into the demineralized dentin (DD) matrix during wet-bonding. Herein, we show that reconciling interfacial compatibility conflict between the DD matrix and the critical hydrophobic adhesive molecules via hydrophobizing the DD matrix enables the adhesives to thoroughly infiltrate and uniformly distribute within the DD matrix. Thus, the bonding of the hydrophobic DD matrix using commercial dentin adhesives achieves the bonding strength 2-6 times higher than that of the non-treated DD matrix. When a hydrophobic adhesive is applied on the hydrophobic DD matrix, a flawless hybrid layer is produced as observed by nanoleakage investigation. A long-term bonding strength comes up to 7.3 fold that of the control group and very importantly, with no attenuation after 12 months. This study clarifies the basic cause of poor wet-bonding durability and demonstrates a paradigm in adhesive dentistry to overcome the long-existing bonding durability problem associated with inadequate adhesive infiltration into the DD matrix. This provides a new angle of view to resolve clinical dentin bonding durability problem and will significantly promote adhesive dentistry.HighlightsInherent interfacial compatibility conflict between demineralized dentin matrix and hydrophobic molecules of dentin adhesives is the basic cause for the dentin bonding durability problem.Reconciling the interfacial compatibility conflict markedly facilitates adhesive infiltration in the demineralized dentin matrix and greatly enhances bonding effectiveness.High interfacial compatibility produces a flawless hybrid layer and ideal bonding effectiveness and durability.Graphical AbstractFor wet bonding, poor infiltration of adhesives within the DD matrix inevitably produces numerous defects throughout the hybrid layer, which always leads to the failure of restoration. Via hydrophobizing the DD matrix, reconciling interfacial compatibility conflict between the DD matrix and the hydrophobic adhesive monomers overcomes durability problems associated with the infiltration of adhesives into the DD matrix producing a flawless hybrid layer and providing ideal bonding effectiveness and durability.