Biomedical Ti–Mo Alloys with Surface Machined and Modified by Laser Beam: Biomechanical,Histological, and Histometric Analysis in Rabbits

Purpose: In vivo bone response was assessed by removal torque, hystological and histometrical analysis on a recently developed biomedical Ti‐15Mo alloy, after surface modification by laser beam irradiation, installed in the tibia of rabbits. Materials and Methods: A total of 32 wide cylindrical Ti‐15Mo dental implants were obtained (10 mm × 3.75 mm). The implants were divided into two groups: 1) control samples (Machined surface – MS) and 2) implants with their surface modified by Laser beam‐irradiation (Test samples – LS). Six implants of each surface were used for removal torque test and 10 of each surface for histological and histometrical analysis. The implants were placed in the tibial metaphyses of rabbits. Results: Average removal torque was 51.5 Ncm to MS and >90 Ncm to LS. Bone‐to‐implant‐contact percentage was significantly higher for LS implants both in the cortical and marrow regions. Conclusions: The present study demonstrated that laser treated Ti‐15Mo alloys are promising materials for biomedical application.     

Biomechanical and Bone Histomorphological Evaluation of Two Surfaces on Tapered and Cylindrical Root Form Implants: An Experimental Study in Dogs

Purpose: The aim of this study was to evaluate the early bone response of tapered and cylindrical root form implants with two different surface treatments in fresh extraction sockets after 4 and 8 weeks. Materials and Methods: Surface treatments and implant design comprised (n = 9 each): tapered with dual acid‐etched surface; tapered with dual acid‐etched and sandblasted surface (T DAE SB); cylindrical with dual acid‐etched surface (C DAE); and cylindrical with dual acid‐etched and sandblasted surface (C DAE SB). Implants were placed in the distal sockets of mandibular premolars (₂P_2,3P_3,4P₄) of six beagle dogs, remaining in vivo for 4 and 8 weeks. After sacrifice, the implants were subjected to torque to the point of interface fracture and subsequently nondecalcified for histomorphological study. Statistical analysis was performed by a General Linear Model (GLM) analysis of variance model with a significance level of 5%. Results: Torque to interface fracture was significantly greater for the C DAE SB group than for the other groups (p < .001). Histomorphological analysis showed woven bone formation around all implant surfaces at 4 weeks and its replacement by lamellar bone at 8 weeks. Study time (4 or 8 weeks) did not affect torque measures. Conclusions: The double acid‐etched and sandblasted sample surface increased early bone biomechanical fixation of both cylindrical and tapered root form implants. The cylindrical root form implants showed higher torque to interface fracture values when compared with the tapered root form implants. The C DAE SB surface group showed the highest biomechanical fixation values (p < .001).     

A Comparison between Endodontics and Implantology: An 8‐Year Retrospective Study

Purpose: The aim of this study was to compare endodontic and implant treatments and to evaluate their predictability over an 8‐year period on the basis of an analysis of survival data and a retrospective clinical study. Materials and Methods: A group of 40 partially edentulous patients were selected for this study. Their teeth had been endodontically treated and rehabilitated using gold alloy and ceramic restorations. In these patients, 65 osseointegrated implants were restored with single gold alloy–ceramic crowns and monitored on a yearly basis for 8 years with standardized periapical radiographs, using a polivynilsiloxane occlusal key as a positioner. A total of nine patients who did not attend the yearly follow‐up were excluded from the study. The Melloning and Triplett criteria were used to evaluate the clinical results obtained in the implant sites. The clinical results of the 56 endodontically treated teeth, restored with the fixed prosthesis of 40 patients, were analyzed according to probing depth as well as an assessment of the correct apical and coronal seals. The survival rate was calculated using the Kaplan–Meier method and the statistical significance was calculated using the chi‐square test. Results: During the follow‐up of the endodontically treated elements, seven failures were detected (83.34%) and the success rate of implants inserted in the same patients was equal to 80.8%, with nine implants lost in 8 years. The survival analysis of the elements treated with both therapies was not statistically significant (p = .757) and the confidence interval was between 0.2455 and 2.777. Conclusion: In view of the superimposable results between the two therapies, it should be noted that the endodontically treated teeth could be interested by different pathologies while the restoration of the atrophic edentulous ridge with an implant support is predictable when patients comply with correct oral hygiene and when the occlusal loads are axially distributed in implant‐protected occlusion.     

Socioeconomic and psychosocial predictors of dental healthcare use among Brazilian preschool children

Background

Disparities in utilization of oral healthcare services have been attributed to socioeconomic and individual behavioral factors. Parents’ socioeconomic status, demographics, schooling, and perceptions of oral health may influence their children’s use of dental services. This cross-sectional study assessed the relationships between socioeconomic and psychosocial factors and the utilization of dental health services by children aged 1–5 years.

Methods

Data were collected through clinical exams and a structured questionnaire administered during the National Day of Children’s Vaccination. A Poisson regression model was used to estimate prevalence ratios and 95% confidence intervals.

Results

Data were collected from a total of 478 children. Only 112 (23.68%) were found to have visited a dentist; 67.77% of those had seen the dentist for preventive care. Most (63.11%) used public rather than private services. The use of dental services varied according to parental socioeconomic status; children from low socioeconomic backgrounds and those whose parents rated their oral health as “poor” used dental services less frequently. The reason for visiting the dentist also varied with socioeconomic status, in that children of parents with poor socioeconomic status and who reported their child’s oral health as “fair/poor” were less likely to have visited the dentist for preventive care.

Conclusion

This study demonstrated that psychosocial and socioeconomic factors are important predictors of the utilization of dental care services.

     

High HIF-1α expression genotypes in oral lichen planus

Objective

The aim of this study is to assess whether C1772T and G1790A hypoxia-inducible factor-1 (HIF-1)α polymorphisms are associated with risk of oral lichen planus (OLP).

Material and methods

Restriction fragment length polymorphism analysis was used to investigate HIF-1α C1779T and G1790A polymorphisms in 32 OLP and 88 individuals without OLP.

Results

The frequency of the CC, TT, GA, and AA genotypes was higher in patients with OLP. Notably, individuals carrying the C and A, and T and A haplotypes showed a significant association OLP risk.

Conclusions

Our study demonstrated that the C1772T and G1790A polymorphisms of HIF-1α gene increased the risk of OLP. C1772T and G1790A polymorphisms of HIF-1α gene had differing patterns of allelic imbalance in the normal samples and subsequent chronic lesions. Further studies are necessary to elucidate the HIF-1α pathway in OLP, which would facilitate the development of novel therapeutic strategies for the prevention and treatment of OLP.

Clinical relevance

These results, in conjunction with previous studies, suggest that HIF-1α may play important roles in the chronicity of oral mucosa lesions of OLP patients. Taken together, we suggest that HIF-1α polymorphisms enhance its target genes, thereby altering the microenvironment and supporting sequential release of inflammatory mediators or cellular events in OLP. It appears unlikely that inhibition of a single proinflammatory mediator will prove useful in clinical practice, but several ways to reprogram mediators engaged in a wide array of roles simultaneously are encouraging.     

In vitro antimicrobial activity of auxiliary chemical substances and natural extracts on Candida albicans and Enterococcus faecalis in root canals

Objective:

The aim of this study was to evaluate the antimicrobial activity of auxiliary chemical substances and natural extracts on Candida albicans and Enterococcus faecalis inoculated in root canals.

Material and Methods:

Seventy-two human tooth roots were contaminated with C. albicans and E. faecalis for 21 days. The groups were divided according to the auxiliary chemical substance into: G1) 2.5% sodium hypochlorite (NaOCl), G2) 2% chlorhexidine gel (CHX), G3) castor oil, G4) glycolic Aloe vera extract, G5) glycolic ginger extract, and G6) sterile saline (control). The samples of the root canal were collected at different intervals: confirmation collection, at 21 days after contamination; 1^st collection, after instrumentation; and 2^nd collection, seven days after instrumentation. Microbiological samples were grown in culture medium and incubated at 37º C for 48 hours.

Results:

The results were submitted to the Kruskal-Wallis and Dunn (5%) statistical tests. NaOCl and CHX completely eliminated the microorganisms of the root canals. Castor oil and ginger significantly reduced the number of CFU of the tested bacteria. Reduction of CFU/mL at the 1^st and 2^nd collections for groups G1, G2, G3 and G4 was greater in comparison to groups G5 and G6.

Conclusion:

It was concluded that 2.5% sodium hypochlorite and 2% chlorhexidine gel were more effective in eliminating C. albicans and E. faecalis, followed by the castor oil and glycolic ginger extract. The Aloe vera extract showed no antimicrobial activity.     

Evaluation of adjunctive perampanel in patients with refractory partial‐onset seizures: Results of randomized global phase III study 305

Purpose: To assess the efficacy and safety of once‐daily doses of perampanel 8 and 12 mg when added to 1–3 concomitantly administered, approved antiepileptic drugs (AEDs) in patients with uncontrolled partial‐onset seizures. Methods: Study 305 was a multicenter, double‐blind, placebo‐controlled trial in patients aged 12 years and older with ongoing seizures despite prior therapy with at least two AEDs, and currently receiving 1–3 AEDs. Equal randomization to once‐daily oral perampanel 8 or 12 mg, or placebo was performed. Patients entered a 19‐week double‐blind treatment phase comprising a 6‐week titration period, with weekly 2‐mg dose increments, followed by a 13‐week maintenance period. Primary efficacy end points were the responder rate (proportion of patients who had a ≥50% reduction in seizure frequency during treatment per 28 days relative to baseline), and the percent change in seizure frequency per 28 days relative to pre‐perampanel baseline. A secondary end point was percent change in the frequency of complex partial plus secondarily generalized seizures. Adverse events (AEs) were monitored throughout the study. Key Findings: Three hundred eighty‐six patients were randomized and treated with study medication. Of these, 321 patients completed the study. The 50% responder rates (intent‐to‐treat analysis) were 14.7%, 33.3%, and 33.9%, respectively, for placebo, perampanel 8 mg, and perampanel 12 mg, with significant improvements over placebo for both perampanel 8 mg (p = 0.002) and 12 mg (p < 0.001). The median percent change from baseline in seizure frequency per 28 days (intent‐to‐treat analysis) was ?9.7%, ?30.5%, and ?17.6% for placebo, 8 mg, and 12 mg, respectively, with significant reductions compared with placebo for both 8 mg (p < 0.001) and 12 mg (p = 0.011). For complex partial seizures plus partial seizures that secondarily generalized, the median percent change in frequency was ?32.7% (8 mg), ?21.9 (12 mg), and ?8.1% (placebo), with significant reductions for both 8 mg (p < 0.001) and 12 mg (p = 0.005). The most frequent (occurring in ≥10% of patients in any treatment group) treatment‐emergent AEs were dizziness, somnolence, fatigue, and headache, with an apparent dose effect suggested for all except headache. Significance: This phase III trial demonstrated that adjunctive treatment with once‐daily perampanel at 8 mg and 12 mg was effective in improving seizure control in patients 12 years and older with refractory partial‐onset seizures. These study results also demonstrated that once‐daily doses of 8 mg and 12 mg were safe and acceptably tolerated in this study. Perampanel demonstrated a favorable risk/benefit ratio in this population.     

Perampanel,a selective,noncompetitive α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid receptor antagonist,as adjunctive therapy for refractory partial‐onset seizures: Interim results from phase III,extension study 307

Purpose: To evaluate safety, tolerability, and seizure outcome data during long‐term treatment with once‐daily adjunctive perampanel (up to 12 mg/day) in patients with refractory partial‐onset seizures. Methods: Study 307 was an extension study for patients completing the double‐blind phase of three pivotal phase III trials (studies 304, 305, and 306). The study consisted of two phases: an open‐label treatment phase (including a 16‐week blinded conversion period and a planned 256‐week maintenance period) and a 4‐week follow‐up phase. Patients were blindly titrated during the conversion period to their individual maximum tolerated dose (maximum 12 mg/day). Adverse events (AEs) were monitored throughout the study and seizure frequency recorded. The interim data cutoff date for analyses was December 1, 2010. Key Findings: In total, 1,218 patients were enrolled in the study. At the interim cutoff date, 1,186 patients were in the safety analysis set; 1,089 (91.8%) patients had >16 weeks of exposure to perampanel, 580 (48.9%) patients had >1 year of exposure, and 19 (1.6%) patients had >2 years of exposure. At the interim analysis, 840 (70.8%) patients remained on perampanel treatment. The large majority of patients (n = 1,084 [91%]) were titrated to 10 mg or 12 mg/day. Median (range) duration of exposure was 51.4 (1.1–128.1) weeks. Treatment‐emergent AEs were reported in 87.4% of patients. The most frequent were dizziness (43.9%), somnolence (20.2%), headache (16.7%), and fatigue (12.1%). Serious AEs were reported in 13.2% of patients. In the intent‐to‐treat analysis set (n = 1,207), the frequency of all seizures decreased over the first 26 weeks of perampanel treatment in patients with at least 26 weeks of exposure to perampanel (n = 1,006 [83.3%]); this reduction was maintained in patients with at least 1 year of exposure (n = 588 [48.7%]). The overall median percent changes in seizure frequency in patients included in each 13‐week interval of perampanel treatment were ?39.2% for weeks 14–26 (n = 1,114), ?46.5% for weeks 40–52 (n = 731), and ?58.1% for weeks 92–104 (n = 59). Overall responder rates in patients included in each 13‐week interval of perampanel treatment were 41.4% for weeks 14–26 (n = 1,114), 46.9% for weeks 40–52 (n = 731), and 62.7% for weeks 92–104 (n = 59). During the blinded conversion period, the reduction in seizure frequency in patients previously randomized to placebo (?42.4%, n = 369) was similar to that in patients previously randomized to perampanel (?41.5%, n = 817). Significance: Consistent with pivotal phase III trials, these interim results demonstrated that perampanel had a favorable tolerability profile in patients with refractory partial‐onset seizures over the longer term. The decrease in seizure frequency was consistent and maintained in those patients over at least 1 year of perampanel exposure.