BPR: Bonded Porcelain Restorations
"The great potential of bonded porcelain restorations can be understood with respect to the scientific and clinically relevant parameters related to biology, function, and mechanics. Ceramic veneers also provide the operator w ith a powerful moda lity for esthetics. Even when esthetics is not the primary objeclive, it still requires special consideration. Modification of form, position, and color of anterior teeth generates significant effects on the smile, which in turn can enhance the patient's personality and social life. "
Deep Margin Elevation
Deep Margin Elevation is a useful tool when sub gingival interdental margins are encountered in indirect adhesive restorations. Subgingival margins, of coarse, can complicate the use of adhesives and composites due to the inability to maintain the proper environment. Isolation, impression taking, and delivery are subsequently hindered, leading to a poor prognosis of the restoration.The margins on these restorations also have poor durability and their relationship with the periodontal tissues can lead to increased inflammation and possible bone loss. This article proposes a technique involving placement of a modified Tofflemire matrix followed by immediate dentin sealing and coronal elevation of the deep margin to a supragingival position using a direct bonded composite resin base. The deep margin elevation technique may be a useful noninvasive alternative to surgical crown lengthening. Dr. Magne outlines the procedure and Dr Matt Nejad performs a clinical case which can be found in those links. They are both a very interesting read and are worth your time.
How to be Biometically Responsible with Severe Dental Erosion
Making a suggestion for treatment for severe dental erosion, that allows for a good prognosis, can be a tough decision. There are many factors that come into play. The options normally include full coverage crowns with inlays being a good secondary choice. Ultra thin bonded posterior occlusal veneers represent a biomimetic alternative for these severe erosive lesions. Composite resins, Paradigm MZ100 or XR, are recommended as these had a 60% and 100% survival rate in a fatigue test. Empress Cad and e.max CAD initially failed at early stress levels. CAD/CAM composites may provide better fracture resistance for non retentive ultra thin occlusal veneers in posterior teeth with high load requirements. If porcelain is needed, e.max CAD for only normal occlusal conditions.
The progressive reduction of enamel thickness is a normal biological process. Accelerated conditions, due to GERD or GERD type related conditions, can lead to destructive consequences. Initial treatment should be to address the etiology of the condition to prevent further complications. Some potential treatment options are clinical follow ups, noninvasive dentin sealing with a filled dentin bonding agent, or even a conservative direct composite resin restorations. Some things to consider when restoring these types of cases are: maintaining occlusal vertical dimension, restoring proper shape and anatomy of the dentition, reducing sound dental tissues, as well as the patients desires and awareness of esthetics and tissue conservation. If the patient has already lost a great deal of tooth structure, treatments that require additional reduction may be contraindicated for a restoration. Only bonded ceramics and composite resins address the biomimetic principles of tissue conservation and esthetics. The developments of ceramics that are stronger (lithium disilicate glass ceramic), etchable, an machinable has extended the indications for bonded ceramic restorations.
Composite resins have also improved greatly, through a superior bond between the different phases. There is a greater amount of stress distribution due to the post-polymerization process. Some of the key characteristics are the low abrasiveness to antagonistic teeth (enamel preservation) and low elastic modulus that allows for more absorption of functional stresses through deformation. Thick CAD/CAM milled composite resin overlays have exceeded that of porcelain ones recently. Ultra thin composite restorations have also become indicated based on the same biomechanics of the composite. Enamel and dentin are unique tissues with highly specialized function. Using extremely thin “enamel-like” restorations, the bonding strategy becomes yet more important. When restoring a tooth, according to biomimetic principles, one should consider both the restorative materials that best emulates enamel and dentin, but also consider the simulation of the DEJ through the interfacial restoration-dentin bond, which can be considered a true composite structure. CAD/CAM composite resins can be recommended for fabricating ultra-thin occlusal veneers in posterior teeth even in patients with high load requirements. Composite should be the material of choice when restoring difficult dental erosion cases.
Luis Schlichting et al, wrote a beautiful article regarding these concepts and to which all material for this post was taken from. It is welt worth the read.