International Journal of Esthetic Dentistry (EN), 04/2009

The clinical concepts regarding the restoration of root canal treated teeth are not clear today and often based on conjecture due to a lack of sound empirical data. The diversity of published opinions is confusing and may lead to less-than-optimal treatment selections. There is also emerging debate whether or not a post is necessary. The purpose of the present article is to organize this topic in evidence-based principles and provide dental practitioners with clear guidelines about restorative therapy for premolar and molar teeth. Two clinical reports are presented, to exemplify the different clinical situations. The first case highlights a conservative restoration of an endodontically treated molar, maintaining an adequate quantity of healthy residual tissue and only covering the cusp with restoration material, which was not sustained by healthy dentin. In the second case, the fact that the premolar was so badly damaged by carious pathology meant that it was necessary to use a pin to anchor the composite material, and the cusp was covered completely. Based on the two presented clinical reports and a literature review, the concept of fiber post application is explained. Searches by hand and MEDLINE were employed to identify peer-reviewed articles on reconstruction of endodontically treated posterior teeth. A total of 70 articles published between 1967 and 2008 were reviewed.

Implant therapy success in the anterior maxilla is judged not only by osseointegration, but also by having sound and stable peri-implant tissues that appear identical to the gingiva surrounding the healthy adjacent teeth. The creation of predictable peri-implant esthetics requires proper preservation of the osseous and soft tissues surrounding the failing teeth, proper three-dimensional implant placement, and proper understanding of prosthetic management. It is now possible to place immediate implants and immediate prostheses to improve esthetics and to simplify treatment, but this technique does not seem to have a stable long-term buccal mucosa. To avoid or reduce this negative effect it appears to be important to increase the thickness of the buccal tissues, and to use appropriate implant components. The aim of the present retrospective study was to observe the dimensional alterations of the peri-implant tissues after immediate implants and single-tooth restorations with concave abutments performed on 28 patients, with a mean followup time of 20.4 months.

To enable uneventful and accelerated healing processes to occur, common techniques in plastic periodontal and implant surgery focus on stable postoperative flap positions. Flap stability is, in particular, positively influenced by an adequate suturing technique, which therefore represents one important factor with regard to the predictability of successful treatment outcomes. The following article illustrates the use of a modified suturing technique, which aims to improve wound adaptation and soft tissue stabilization after surgical treatment with tunneling flap preparation techniques. Anchored at the incisal contact points of the affected teeth, the suture is crossed through the buccal as well as through the palatal aspect. In this manner, the suture maintains the surgically established coronal displacement of the buccal flap and provides a stable and intimate contact to the underlying tissues.

An ideal all-ceramic restoration that conforms well and demonstrates enhanced biocompatibility, strength, fit, and esthetics has always been desirable in clinical dentistry. However, the inherent brittleness, low flexural strength, and fracture toughness of conventional glass and alumina ceramics have been the main obstacles for extensive use. The recent introduction of zirconia-based ceramics as a restorative dental material has generated considerable interest in the dental community, which has been expressed with extensive industrial, clinical, and research activity. Contemporary zirconia powder technology contributes to the fabrication of new biocompatible all-ceramic restorations with improved physical properties for a wide range of promising clinical applications. Especially with the development of computer-aided design (CAD)/computer-aided manufacturing (CAM) systems, highstrength zirconia frameworks can be viable for the fabrication of full and partial coverage crowns, fixed partial dentures, veneers, posts and/or cores, primary double crowns, implant abutments, and implants. Data from laboratory and clinical studies are promising regarding their performance and survival. However, clinical data are considered insufficient and the identified premature complications should guide future research. In addition, different zirconia-based dental auxiliary components (ie, cutting burs and surgical drills, extra-coronal attachments and orthodontic brackets) can also be technologically feasible. This review aims to present and discuss zirconia manufacturing methods and their potential for successful clinical application in dentistry.

The aim of the present study was to investigate the effect of gender on the degree of maxillary and mandibular anterior teeth and associated gingival display when the lips are at rest and during smiling. A total of 247 subjects (144 females [58.3%]; 103 males [41.7%]) were included in the study. All of the subjects had all natural anterior teeth present with no caries, extreme occlusal wear, restorations, extrusion, obvious deformities, or tooth mobility. Subjects with a history of congenital anomalies, lip trauma, or facial surgery were excluded. Crown length, displayed portions of anterior teeth, and associated gingivae at rest and during smiling were measured using a Fowler electronic digital caliper, which had a resolution of 0.01mm. The visible portions of the maxillary anterior teeth were measured vertically from the lower border of the upper lip to the incisal edge of the incisors, or cusp tip for the canines. The visible portions of the mandibular anterior teeth were measured vertically from the upper border of the lower lip to the incisal edges of the incisors, or cusp tip for the canines at the midpoint of the tooth. The measurements were taken by two independent clinicians and they were repeated three times and the mean value was calculated for further analysis. SPSS (V 11) software was used to analyse the data. Statistical analyses were performed by Student t test and ANOVA. The significance level was set at 5%. At rest, males displayed significantly more buccal length for maxillary lateral incisors (1.85 ± 1.27 vs 1.43 ± 1.37; P < 0.01), maxillary canines (0.94 ± 0.91 vs 0.35 ± 0.67; P < 0.0001), mandibular central incisors (1.09 ± 1.17 vs 0.82 ± 1.32; P < 0.01), mandibular lateral incisors (0.98 ± 1.07 vs 0.79 ± 1.22; P < 0.05), and mandibular canines (0.87 ± 1.23 vs 0.57 ± 0.98; P < 0.05) than females. However, no gender differences in the display of buccal length of the maxillary central incisor were recorded at rest and during smiling. During smiling, no gender differences in the display of buccal length of the anterior teeth were recorded. Gingival display during smiling presented significant differences between gender groups in the maxillary anterior region, with females displaying more gingivae of central incisors (1.85 ± 1.38 vs 1.73 ± 1.07; P < 0.05), lateral incisors (2.05 ± 0.93 vs 1.94 ± 1.23; P < 0.0001), and canines (2.37 ± 1.24 versus 2.02 ± 1.49; P < 0.05). However, no gender differences were observed in the gingival display of the mandibular anterior region. Females displayed 29% vs 25% of maxillary central incisor crown length compared to males at rest. However, during smiling, 87% of maxillary anterior teeth were displayed in females compared to less than 80% in males. Males displayed more of the maxillary lateral, canine, and mandibular anterior teeth than females at rest. During smiling, no gender differences in anterior tooth display were recorded, however, females displayed more maxillary gingivae than males.

The present study evaluated surface roughness and wear of bovine enamel following three different bleaching techniques and simulated brushing. Initial surface roughness (Ra) was evaluated and teeth were randomly divided into 4 groups (n = 10): Group 1, control; Group 2, 35% hydrogen peroxide (HP) activated by a hybrid light; Group 3, 35% HP activated by a halogen light; and Group 4, 16% carbamide peroxide. After bleaching, surface roughness was measured and teeth were subjected to 100,000 cycles of simulated brushing. After brushing, the final roughness and wear was determined. Data were statistically analyzed by ANOVA and Tukey test (P < 0.05). There were no significant differences among groups comparing initial and postbleaching roughness. After brushing, significant differences were found between the control and experimental groups. Group 4 showed a significant increase in roughness values compared with Group 2. The control group showed significantly less wear than other groups. Bleaching techniques promoted increased roughness and wear of bovine enamel, when submitted to simulated brushing. Tooth enamel after bleaching can present a larger alteration in the amount of roughness due to brushing.