A Double-Blind Randomized Controlled Trial (RCT) of Titanium-13Zirconium versus Titanium Grade IV Small-Diameter Bone Level Implants in Edentulous Mandibles - Results from a 1-Year Observation Period

Background: The use of endosseous dental implants has become common practice for the rehabilitation of edentulous patients, and a two‐implant overdenture has been recommended as the standard of care. The use of small‐diameter implants may extend treatment options and reduce the necessity for bone augmentation. However, the mechanical strength of titanium is limited, so titanium alloys with greater tensile and fatigue strength may be preferable. Purpose: This randomized, controlled, double‐blind, multicenter study investigated in a split‐mouth model whether small‐diameter implants made from Titanium‐13Zirconium alloy (TiZr, Roxolid?) perform at least as well as Titanium Grade IV implants. Methods and Materials: Patients with an edentulous mandible received one TiZr and one Ti Grade IV small‐diameter bone level implant (3.3 mm, SLActive®) in the interforaminal region. The site distribution was randomized and double‐blinded. Outcome measures included change in radiological peri‐implant bone level from surgery to 12 months post‐insertion (primary), implant survival, success, soft tissue conditions, and safety (secondary). Results: Of 91 treated patients, 87 were available for the 12‐month follow‐up. Peri‐implant bone level change (?0.3 ± 0.5 mm vs ?0.3 ± 0.6 mm), plaque, and sulcus bleeding indices were not significantly different between TiZr and Ti Grade IV implants. Implant survival rates were 98.9 percent and 97.8 percent, success rates were 96.6 percent and 94.4 percent, respectively. Nineteen minor and no serious adverse events were related to the study devices. Conclusion: This study confirms that TiZr small‐diameter bone level implants provide at least the same outcomes after 12 months as Ti Grade IV bone level implants. The improved mechanical properties of TiZr implants may extend implant therapy to more challenging clinical situations.     

Multivariate analysis of risk factors for development of duodenal ulcer in Helicobacter pylori-infected patients

BACKGROUND: Although Helicobacter pylori is a significant etiologic factor of peptic ulcer disease, it remains unknown why ulcers develop only in the minority of infected individuals. AIM: The aim of this cross-sectional study was to evaluate the association between the presence of duodenal ulcer in H. pylori-infected patients and different risk factors. METHODS: A total of 122 H. pylori-infected patients were enrolled; 79 had duodenal ulcer and 43 gastritis. Univariate analysis was conducted using either Fisher's exact test or exact Cochrane-Armitage trend test. In multivariate analysis the logistic model was used. RESULTS: Univariate analysis indicated six factors (male sex, smoking, antral H. pylori density, CAGA presence in antrum, and VACA s1a presence in antrum and corpus). Four factors (sex, smoking-alcohol index, H. pylori density index, and CAGA index) were found to be significant in multivariate analysis. The best model predicting duodenal ulcer included male sex, smoking, presence of H. PYLORI on histopathology in antrum and CAGA presence in corpus. CONCLUSION: Although several risk factors were significantly associated with duodenal ulcer, we failed in the identification of either a single risk factor or a set of factors that can unequivocally differentiate patients with ulcer from those with gastritis.     

Kohlschütter–Tönz Syndrome: Mutations in ROGDI and Evidence of Genetic Heterogeneity

Kohlschütter–Tönz syndrome (KTS) is a rare autosomal recessive disorder characterized by amelogenesis imperfecta, psychomotor delay or regression and seizures starting early in childhood. KTS was established as a distinct clinical entity after the first report by Kohlschütter in 1974, and to date, only a total of 20 pedigrees have been reported. The genetic etiology of KTS remained elusive until recently when mutations in ROGDI were independently identified in three unrelated families and in five likely related Druze families. Herein, we report a clinical and genetic study of 10 KTS families. By using a combination of whole exome sequencing, linkage analysis, and Sanger sequencing, we identify novel homozygous or compound heterozygous ROGDI mutations in five families, all presenting with a typical KTS phenotype. The other families, mostly presenting with additional atypical features, were negative for ROGDI mutations, suggesting genetic heterogeneity of atypical forms of the disease.     

Dark chocolate reduces endothelial dysfunction after successive breath-hold dives in cool water

Objective

The aim of this study is to observe the effects of dark chocolate on endothelial function after a series of successive apnea dives in non-thermoneutral water.

Methods

Twenty breath-hold divers were divided into two groups: a control group (8 males and 2 females) and a chocolate group (9 males and 1 female). The control group was asked to perform a series of dives to 20 m adding up to 20 min in the quiet diving pool of Conflans-Ste-Honorine (Paris, France), water temperature was 27 °C. The chocolate group performed the dives 1 h after ingestion of 30 g of dark chocolate. Flow-mediated dilatation (FMD), digital photoplethysmography, nitric oxide (NO), and peroxynitrite ONOO^?) levels were measured before and after each series of breath-hold dives.

Results

A significant decrease in FMD was observed in the control group after the dives (95.28 ± 2.9 % of pre-dive values, p < 0.001) while it was increased in the chocolate group (104.1 ± 2.9 % of pre-dive values, p < 0.01). A decrease in the NO level was observed in the control group (86.76 ± 15.57 %, p < 0.05) whereas no difference was shown in the chocolate group (98.44 ± 31.86 %, p > 0.05). No differences in digital photoplethysmography and peroxynitrites were observed between before and after the dives.

Conclusion

Antioxidants contained in dark chocolate scavenge free radicals produced during breath-hold diving. Ingestion of 30 g of dark chocolate 1 h before the dive can thus prevent endothelial dysfunction which can be observed after a series of breath-hold dives.     

The synthetic progestogen, Levonorgestrel, but not natural progesterone, affects male mate calling behavior of Xenopus laevis

Worldwide, more than 100 million women use hormonal contraceptives, which act through progestogenic modes of action. These man-made hormones can enter the aquatic environment as they are excreted via feces and urine. Xeno-progestins are able to interfere with the endocrine system of female aquatic vertebrates impairing oogenesis and reproduction. However, data on progestogenic effects on reproductive behavior of male aquatic vertebrates are lacking. To evaluate whether progestins affect the mating behavior of male Xenopus laevis, we exposed male frogs to three environmentally relevant concentrations (10(-7) M, 10(-8) M and 10(-10) M) of the synthetic progestin Levonorgestrel (LNG) and the corresponding natural steroid progesterone (PRG), respectively. LNG at all exposure concentrations increased the proportions of advertisement calling, indicating a sexually aroused state of the males. Furthermore LNG at 10(-7) M decreased the relative proportions of rasping, a call type indicating a sexually unaroused state of the male. PRG, on the other hand, did not affect any of those parameters. Temporal and spectral features of the advertisement call itself were not affected by any of the two exposure treatments. Since LNG exhibits slight androgenic activity, the results suggest that LNG effects on male mate calling behavior of X. laevis are due to its moderate androgenic but not to its progestogenic activities. However, although males' sexual arousal seems to be enhanced by LNG, the adverse effects of LNG on female reproduction presumably outweigh these enhancing effects and LNG exposure nonetheless might result in reduced reproductive success of these animals.     

Changes in oro-facial function and hand-grip strength during a 2-year observation period after stroke

Objectives

Recovery from stroke-related oro-facial impairment has rarely been investigated. In this longitudinal study chewing efficiency, maximum lip and bite force as well as masseter muscle thickness were evaluated and compared with hand-grip force.

Materials and methods

Thirty-one hospitalized stroke patients and 24 controls were recruited for this cohort study with 2-year follow-up. Chewing efficiency was evaluated with a color mixing ability test, lip forces with a traction dynamometer, bite force with a digital gauge, masseter muscle thickness using ultrasound measurements and grip strength with a hand dynamometer.

Results

During the 2-year observation period, patients were evaluated four times. A total of 21 patients dropped out of the study. Stroke patients showed significantly impaired chewing efficiency and lower lip forces than controls with no significant improvement over time. Bite forces were not different between ipsi- and contralesional sides, in contrast to contralesional hand-grip strength which was significantly impaired and did not improve during the observation period. On the first examination with a median of 40 days after stroke, masseter thickness was reduced contralesional, but did not continue to show significant side-differences during follow-up.

Conclusions

Stroke affects the upper limb and the masseter muscles differently on a functional and morphological level. Further research is needed to evaluate the predictive value of oro-facial parameters on functional outcome after stroke.

Clinical relevance

Impaired chewing efficiency and reduced lip force are quantifiable symptoms in stroke patients which seem not to improve in absence of oro-facial rehabilitation procedures.