Long-Term Clinical Behavior and Complications of Intentionally Tilted Dental Implants Compared with Straight Implants Supporting Fixed Restorations: A Systematic Review and Meta-Analysis.

The aim of this study was to assess the long-term clinical behavior of straight implants in comparison with intentionally tilted dental implants (ITDI) supporting fixed restorations in partial or total edentulous arches, analyzing implant survival and success rates, complications, and marginal bone loss (MBL) after >5 years of function. An electronic search was conducted in five electronic databases (MEDLINE/Pubmed, Embase, Web of Science, Scopus, and Cochrane Central Register of Controlled Trials) supplemented by a manual search. The electronic and manual search identified 1853 articles, of which 8 articles were selected for analysis. Out of a total of 3987 dental implants, 2036 were axial dental implants and 1951 tilted. Similar results were found in implant survival or overall implant success rates. Moreover, no statistically significant differences were found in MBL (p = 0.369; MD 0.116 mm (-0.137; 0.369) 95% CI) The prosthodontic/biological complications reported in the articles were very diverse and irregularly distributed. This systematic review suggests that there is no difference between tilted compared with straight dental implants in the medium-long term (>5 years). However, further research is needed to generate long-term data and confirm the present review's findings.

Adhesion to Zirconia: A Systematic Review of Surface Pretreatments and Resin Cements.

This systematic review aims to evaluate the different pretreatments of the zirconia surface and resin cement in order to determine a valid operative protocol for adhesive cementation. Methodologies conducted for this study followed the Prisma (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines. An electronic search was performed in four databases. The established focus question was: "What type of surface conditioning method is the one that obtains the best adhesion values to zirconia over time by applying a resin cement?" Forty-five relevant papers were found to qualify for final inclusion. In total, 260 different surface pretreatment methods, mainly combinations of air-abrasion protocols and adhesive promoters, were investigated. Altogether, the use of two artificial aging methods, three types of cement and four testing methods was reported. The results showed that mechanicochemical surface pretreatments offered the best adhesive results. Self-adhesive cement and those containing 10-MDP obtained the best results in adhesion to zirconia. Artificial aging reduced adhesion, so storage in water for 30 days or thermocycling for 5000 cycles is recommended. A standardized adhesive protocol has not been established due to a lack of evidence.

Early tacrolimus exposure does not impact long-term outcomes after liver transplantation.

BACKGROUND: Tacrolimus trough levels (TTL) during the first weeks after liver transplantation (LT) have been related with long-term renal function and hepatocellular carcinoma recurrence. Nevertheless, the significance of trough levels of tacrolimus during the early post-transplant period for the long-term outcome is under debate. AIM: To evaluate the effect of TTL during the first month on the long-term outcomes after LT. METHODS: One hundred fifty-five LT recipients treated de novo with once-daily tacrolimus were retrospectively studied. Patients with repeated LT or combined transplantation were excluded as well as those who presented renal dysfunction prior to transplantation and/or those who needed induction therapy. Patients were classified into 2 groups according to their mean TTL within the first month after transplantation: ≤ 10 (n = 98) and > 10 ng/mL (n = 57). Multivariate analyses were performed to assess risk factors for patient mortality. RESULTS: Mean levels within the first month post-transplant were 7.4 ± 1.7 and 12.6 ± 2.2 ng/mL in the ≤ 10 and > 10 groups, respectively. Donor age was higher in the high TTL group 62.9 ± 16.8 years vs 45.7 ± 17.5 years (P = 0.002) whilst mycophenolate-mofetil was more frequently used in the low TTL group 32.7% vs 15.8% (P = 0.02). Recipient features were generally similar across groups. After a median follow-up of 52.8 mo (range 2.8-81.1), no significant differences were observed in: Mean estimated glomerular filtration rate (P = 0.69), hepatocellular carcinoma recurrence (P = 0.44), de novo tumors (P = 0.77), new-onset diabetes (P = 0.13), or biopsy-proven acute rejection rate (12.2% and 8.8%, respectively; P = 0.50). Eighteen patients died during the follow-up and were evenly distributed across groups (P = 0.83). Five-year patient survival was 90.5% and 84.9%, respectively (P = 0.44), while 5-year graft survival was 88.2% and 80.8%, respectively (P = 0.42). Early TTL was not an independent factor for patient mortality in multivariate analyses. CONCLUSION: Differences in tacrolimus levels restricted to the first month after transplant did not result in significant differences in long-term outcomes of LT recipients.

Allergies to Titanium Dental Implants: What Do We Really Know about Them? A Scoping Review.

The purpose of this scoping review was to describe the current state of knowledge and understanding of allergies to titanium dental implants. A scoping review was conducted following the Prisma Extension for Scoping Reviews checklist. An electronic search was performed in five databases complemented by manual and grey literature searches. Fifty-two relevant papers were included for final review. Titanium particles can be released from the surfaces of dental implants in a process called tribocorrosion, which may contribute to bone loss due to inflammatory reaction. Diverse mechanisms have been described that may trigger allergy to titanium, as well as the clinical signs that manifest as the allergy develops. Allergies to titanium are uncommon but represent a real possibility that should not be overlooked in patients requiring prosthodontic rehabilitation with dental implants. Allergy can trigger a range of symptoms. Patients who have already been diagnosed with allergies to other metals will be more predisposed to suffering an allergy to titanium. Further investigation is needed in order to measure the true scope of these allergies.

Fracture resistance and failure mode of posterior fixed dental prostheses fabricated with two zirconia CAD/CAM systems.

BACKGROUND: In recent years there has been an improvement of zirconia ceramic materials to replace posterior missing teeth. To date little in vitro studies has been carried out on the fracture resistance of zirconia veneered posterior fixed dental prostheses. This study investigated the fracture resistance and the failure mode of 3-unit zirconia-based posterior fixed dental prostheses fabricated with two CAD/CAM systems. MATERIAL AND METHODS: Twenty posterior fixed dental prostheses were studied. Samples were randomly divided into two groups (n=10 each) according to the zirconia ceramic analyzed: Lava and Procera. Specimens were loaded until fracture under static load. Data were analyzed using Wilcoxon´s rank sum test and Wilcoxon´s signed-rank test (P<0.05). RESULTS: Partial fracture of the veneering porcelain occurred in 100% of the samples. Within each group, significant differences were shown between the veneering and the framework fracture resistance (P=0.002). The failure occurred in the connector cervical area in 80% of the cases. CONCLUSIONS: All fracture load values of the zirconia frameworks could be considered clinically acceptable. The connector area is the weak point of the restorations. Key words:Fixed dental prostheses, zirconium-dioxide, zirconia, fracture resistance, failure mode.

Conjunctivitis with regional lymphadenopathy in a trainee microbiologist.

We report a case of conjunctival tuberculosis in a trainee microbiologist caused by direct inoculation. The resident strain was analyzed by DNA fingerprinting, and an identical pattern was found in an isolate from sputum handled by the resident. After 6 months of treatment, the patient was cured.

Pamidronate in the prevention of bone loss after liver transplantation: a randomized controlled trial.

Rapid bone loss and high rates of fractures occur following liver transplantation. To analyze the effect of intravenous pamidronate on bone loss after liver transplantation. A randomized, double-blind, placebo-controlled study was performed. Seventy-nine patients were randomized to two groups of treatment: the pamidronate group (n = 38) was treated with 90 mg/IV of pamidronate within the first 2 weeks and at 3 months after transplantation; the placebo group (n = 41) received glucose infusions at the same time points. All patients received calcium and vitamin D. Bone mineral density (BMD) at the lumbar spine (L(2)-L(4)) and proximal femur using dual energy X-ray absorptiometry and also spinal X-rays were performed before, and at 6 and 12 months after liver transplantation. Biochemical and hormonal determinations were performed previous to transplantation, at 24 h before and after treatment, as well as at 6 and 12 months after liver transplantation. At 12 months after transplantation, there were significant differences in lumbar BMD changes (6 months: pamidronate 1.6% vs. placebo 0.8%, P = NS; 12 months: pamidronate 2.9% vs. placebo 1%, P < 0.05). Femoral neck BMD decreased in the pamidronate- and placebo groups during the first 6 months (6 months: pamidronate -3.1% vs. placebo -2.9%, P = NS; 12 months: pamidronate -3.2% vs. placebo -3.1%, P = NS). BMD at the trochanter remained stable in the pamidronate group, whilst a reduction was observed in the placebo group at 6 months (6 months: pamidronate -0.7% vs. placebo -3.7%, P < 0.05; 12 months: pamidronate -0.5% vs. placebo -1.2%, P = NS). Moreover, no significant differences in the incidence of fractures, serum parathyroid hormone and serum 25-hydroxyvitamin D values between both groups were found. Pamidronate did not increase the risk of serious adverse events. The results of this study show that 90 mg of intravenous pamidronate within the first 2 weeks and at 3 months following liver transplantation preserve lumbar bone mass during the first year, without significant adverse events. However, pamidronate does not reduce bone loss at the femoral neck and furthermore it does not reduce skeletal fractures.

Three-year clinical evaluation of In-Ceram Zirconia posterior FPDs.

PURPOSE: The purpose of this study was to evaluate the clinical performance of In-Ceram Zirconia posterior fixed partial dentures (FPD) after 3 years in service. MATERIALS AND METHODS: Eighteen In-Ceram Zirconia FPDs were fabricated in 16 patients. The FPDs were placed between January and April 1999. The CDA quality evaluation system was used for assessment of surface and color, anatomic form, and marginal integrity. Bleeding on probing was also recorded. RESULTS: One of the 18 posterior FPDs was lost because of a root fracture. All remaining FPDs were rated as either excellent or acceptable after the observation period. Bleeding was more often recorded at crowned abutments with In-Ceram Zirconia than at contralateral teeth. CONCLUSION: In-Ceram Zirconia posterior FPDs seem to be an acceptable treatment alternative in a 3-year perspective. However, more clinical long-term follow-up studies must be performed before the system can be recommended as an alternative to conventional FPDs.