Determination of Facial References for Esthetic Restorative Treatment.

Although it is generally accepted that a prosthetic restoration must take into account the gingiva, smile, and patient's face, it is often difficult to determine precisely what facial references must be considered. The purpose of this study was to determine the correct vertical and horizontal facial reference planes in esthetic prosthetic treatment. Using photographic analysis of 160 individuals, the different facial reference planes (interpupillary, intermeatic, intercommissural, and incisal edge lines; facial midline; and Camper and Frankfort planes) were compared to the ideal prosthetic reconstruction axis. Additional measurements, including the human eye's ability to perceive parallelism, were recorded. Most participants (64%) exhibited facial asymmetry. Asymmetry was horizontal (difference between widths of the right and left sides; 52.4%), vertical (difference between heights of the right and left sides; 6.9%), or mixed (4.7%). The interpupillary line is the main horizontal reference in 88.4% of situations, with the intercommissural line the second most important. In the profile view, the horizontal plane was on average 6.5 degrees above the Camper plane and 9 degrees below the Frankfort plane. The human eye's ability to perceive parallelism between two lines was found to be limited to differences of approximately 1 degree. During anterior tooth reconstruction, it is necessary to take into account the right horizontal and vertical esthetic references. Knowledge of the biometric facial parameters in natural dentition is necessary to define the right reconstruction axes based on the facial symmetry or asymmetry.

A Simplified Approach for Restoration of Worn Dentition Using the Full Mock-up Concept: Clinical Case Reports.

Treatment of tooth wear has increased over the last two decades. However, the treatments involved have not been satisfactory to most patients, nor have they achieved the expected goal on some worn teeth. New approaches have emerged to reconstruct full arches in a minimally invasive way that take advantage of developments in the field of adhesive dentistry. These new concepts constitute a revolution in dentistry and their application requires adapted techniques and training. The purpose of this article is to suggest a precise and reproducible method that simplifies the treatment of worn dentition. A wax-up and a mock-up are primarily used to design the esthetic outcome and then used as a guide for the preparation of anterior teeth or the occlusal surfaces of posterior teeth. This not only provides the exact new vertical dimension of occlusion but serves as a guide for precisely controlling occlusal preparation simultaneously with buccal preparation. The classical cavity design for a partial bonded restoration on posterior worn dentition is also reviewed. The authors believe that during the preparation of the occlusal surfaces of the posterior teeth surfaces, the marginal ridges must be preserved to reduce the biologic cost and mechanical stress leading to fracture. A new type of thin and reduced restoration called tabletop is presented.

Effect of dual cure composite as dentin substitute on the marginal integrity of Class II open-sandwich restorations.

This study compared the marginal adaptation of Class II open-sandwich restorations with an RMGIC versus a dual-cure composite as dentin substitute. Class II cavities were prepared on 50 extracted human third molars. The teeth were randomly assigned to two groups of 25 teeth to compare one dual cure composite (Multicore Flow) with one resin-modified glass-ionomer cement (Fuji II LC) in open-sandwich restorations covered with a light cure composite. The teeth were thermomechanically cycled (2000 cycles, 5 degrees C to 55 degrees C; 100,000 cycles, 50 N/cm2). The specimens were then sealed with a 1 mm window around the cervical margin interface. Samples were immersed in a 50% w/v ammoniacal silver nitrate solution for two hours and exposed to a photodeveloping solution for six hours. The specimens were sectioned longitudinally and silver penetration was directly measured using a light microscope. The results were expressed as a score ranging from 0 to 3. The data were analyzed with a non-parametric Kruskall and Wallis test. The degree of leakage significantly increased with Multicore Flow (median = 2) compared to Fuji II LC (median = 1). The resin-modified glassionomer cements remain the best intermediate materials when open-sandwich restorations are indicated. A comparison of the degradation of these materials over time remains a topic to be investigated by future studies.

Effect of dual cure composite as dentin substitute on marginal integrity of class II open-sandwich restorations.

The current study compared the marginal adaptation of Class II open-sandwich restorations with a RMGIC versus a dual-cure composite as dentin substitute. Class II cavities were prepared on 50 extracted human third molars. The teeth were randomly assigned to two groups of 25 teeth to compare one dual cure composite (MultiCore Flow) with one resin-modified glass-ionomer cement (Fuji II LC) in open-sandwich restorations recovered with a light cure composite. The teeth were thermomechanocycled (2000 cycles, 5 degrees C to 55 degrees C; 100,000 cycles, 50 N/cm2). The specimens were then sealed with a 1 mm window around the cervical margin interface. Samples were immersed in a 50% w/v ammoniacal silver nitrate solution for two hours and exposed to a photo-developing solution for six hours. The specimens were sectioned longitudinally and silver penetration was directly measured using a light microscope. The results were expressed as a score from 0 to 3. The data were analyzed with a non-parametric Kruskal and Wallis test. The degree of leakage significantly increased with MultiCore Flow (median 2) compared to Fuji II LC (median 1). Resin-modified glassionomer cements remain the best intermediate material when open-sandwich restorations are indicated. A comparison of the degradation of these materials over time remains a topic to be investigated by future studies.