A systematic review of the survival and complication rates of zirconia-ceramic and metal-ceramic single crowns.

OBJECTIVES: The aim of the present systematic review was to analyze the survival and complication rates of zirconia-based and metal-ceramic implant-supported single crowns (SCs). MATERIALS AND METHODS: An electronic MEDLINE search complemented by manual searching was conducted to identify randomized controlled clinical trials, prospective cohort and retrospective case series on implant-supported SCs with a mean follow-up time of at least 3 years. Patients had to have been clinically examined at the follow-up visit. Assessment of the identified studies and data extraction was performed independently by two reviewers. Failure and complication rates were analyzed using robust Poisson's regression models to obtain summary estimates of 5-year proportions. RESULTS: The search provided 5,263 titles and 455 abstracts, full-text analysis was performed for 240 articles, resulting in 35 included studies on implant-supported crowns. Meta-analysis revealed an estimated 5-year survival rate of 98.3% (95% CI: 96.8-99.1) for metal-ceramic implant supported SCs (n = 4,363) compared to 97.6% (95% CI: 94.3-99.0) for zirconia implant supported SCs (n = 912). About 86.7% (95% CI: 80.7-91.0) of the metal-ceramic SCs (n = 1,300) experienced no biological/technical complications over the entire observation period. The corresponding rate for zirconia SCs (n = 76) was 83.8% (95% CI: 61.6-93.8). The biologic outcomes of the two types of crowns were similar; yet, zirconia SCs exhibited less aesthetic complications than metal-ceramics. The 5-year incidence of chipping of the veneering ceramic was similar between the material groups (2.9% metal-ceramic, 2.8% zirconia-ceramic). Significantly (p = 0.001), more zirconia-ceramic implant SCs failed due to material fractures (2.1% vs. 0.2% metal-ceramic implant SCs). No studies on newer types of monolithic zirconia SCs fulfilled the simple inclusion criteria of 3 years follow-up time and clinical examination of the present systematic review. CONCLUSION: Zirconia-ceramic implant-supported SCs are a valid treatment alternative to metal-ceramic SCs, with similar incidence of biological complications and less aesthetic problems. The amount of ceramic chipping was similar between the material groups; yet, significantly more zirconia crowns failed due to material fractures.

Predatory publishing in dentistry: an analysis of its impact and potential risks.

The aim of this study was to make a quantitative assessment of the impact that predatory publishing has on a single author over a year, analyzing the number of invitations, the subject areas of the inviting journals and their characteristics. An analysis of all invitations to publication, received during 12 months, was carried out in order to analyze their number, the area of specialization, the presence in reputable databases, publication criteria and presence in the Beall's list. A total of 864 invitations had been received at the end of the 12 months, all with open access policies. Ninety-nine were from journals not on Beall's list. Eight were indexed on reputable databases. The thematic areas were distributed as follows: 370 dental, 346 medical, 122 unspecified subject, 26 non-medical. Predatory publishing is spreading in dentistry. Poor-quality articles and, at the same time, loss of potentially valuable research could seriously pollute the scientific evidence that founds dental clinical practice.

Standard vs customized healing abutments with simultaneous bone grafting for tissue changes around immediate implants. 1-year outcomes from a randomized clinical trial.

BACKGROUND: Immediate implants have shown risks of esthetic complications. The hypothesis was that a customized healing abutment could improve the peri-implant tissue healing. PURPOSE: To evaluate and compare the soft and hard tissue healing around immediate implants that received bone grafting and a customized vs a standard healing abutment. MATERIALS AND METHODS: Patients, who required tooth extraction and who received an immediate implant (with an alloplastic graft material) were randomly assigned to a customized or a standard healing abutment group. Clinical and radiographic examinations were taken at baseline, at 4 and 12 months. RESULTS: Twenty-five patients out of 61 were excluded from the study because unsuitable for immediate implantation. In total, 36 patients were randomized in the two groups. There were 17 females and 19 males (age range 23-77). No prosthetic or implant failure was registered during the study period. The Papilla Index was significantly higher in the customized than in the standard group at 4 and 12 months (P = .0002). The bone loss at mesial sites was significantly higher in the control than in the test group (P = .0014). CONCLUSION: The customized healing abutment group showed the most favorable outcomes (in terms of PI and MBL) in case of immediate implant that received a peri-implant bone grafting procedure.