Histologic and histomorphometric evaluation of new zirconia-based ceramic dental implants: A preclinical study in dogs.

OBJECTIVE: Healing of soft tissues and improvement of aesthetics have become major research objectives in implantology and renewed the interest for ceramics implants. The aim of this study was to evaluate the pre-clinical performance of screw-shaped sandblasted-etched implants processed from an innovative zirconia-based ceramic composite, in comparison to titanium. METHODS: Twenty-four ceramic and twenty-four titanium screw-shaped sandblasted-etched dental implants were tested in a split-mouth design in six Beagle dogs. Surface topographies were investigated by confocal microscopy. Local tissue effects were evaluated at 4 and 13 weeks after implantation through histology. An ANOVA statistical analysis (5% risk; p < 0.05) was performed to compare peri-implant quantitative histomorphometric parameters on buccal and lingual sides, including Bone to Implant Contact (BIC) among test groups and time-periods. RESULTS: Titanium and ceramic implants presented respectively moderate and minimal roughness. After 4 and 13 weeks, ceramic implants showed an inflammatory tissue response close to titanium implants. At both period of time there was no significant difference between the titanium and ceramic groups in terms of BIC values (mean ± SD) at the lingual or buccal sides or when combining buccal + lingual BIC values (respectively for titanium and ceramic, 68.4 ± 14.7 % and 75.0 ± 13.5 % at 4 weeks, and 92.0 ± 8.6 % and 86.1 ± 13.8 % at 13 weeks). SIGNIFICANCE: Within the limits of the present study, it can be concluded that newly developed zirconia-based ceramic composite dental implants have similar biocompatibility and osseointegration to those observed in titanium implants. These pre-clinical results corroborate the potential for the use of these new zirconia-based ceramics in oral implantology.

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.

Immediate loading of mandibular dental implants in partially edentulous patients: a prospective randomized comparative study.

While immediate loading in the edentulous mandible is a well-documented procedure, there are limited scientific data on immediate loading in the partially edentulous mandible. Two-year success rates of immediate loading and conventional delayed loading of dental implants in partially dentate mandibles were compared. Patients were randomized into three groups: group A (n = 40), immediate provisionalization with nonocclusal loading; group B (n = 40), immediate provisionalization with occlusal loading; and group C (n = 37), delayed loading with single-stage surgery. Baseline and 2-year measurements included implant stability quotient, insertion torque, and peri-implant bone crest radiography. Two hundred nine implants were immediately loaded in 80 patients. The 2-year success rates were 93.3% for group B and 100% for groups A and C. Immediate provisionalization provided success rates similar to those for delayed loading only when not loaded in occlusion.

Use of the ditramax system to communicate esthetic specifications to the laboratory.

Prosthetic restoration of the anterior teeth is a major esthetic challenge. Esthetic treatment consists of creating pleasantly proportioned teeth and integrating them harmoniously into the patient's gingiva, lips, and face. The communication of clinical data to the laboratory is critical to the success of any esthetic treatment. The purpose here is to present a straightforward, efficient, and reproducible means of communicating esthetic specifications to ceramists, allowing them to work as though the patient was actually in front of them, with access to all of the major facial esthetic criteria.