Influence of abutment angulation on implant failure in immediately placed and restored implants in the esthetic zone: a randomized clinical trial

Background: Tooth extraction socket in the aesthetic area is a major indication for immediate implant placement greatly improving patient satisfaction and preserving the alveolar ridge. However, the effect of non-axial force on the peri-implant bone with subsequent early implant failure remains unclear. Objective:Evaluate the prognosis of tilted implants immediately placed and restored with angled abutments in comparison to straight implants restored with straight abutments in the esthetic area (anterior or premolars) using computer-aided surgical guides. Material and methods: Badly decayed non-restorable teeth in the aesthetic zone (anterior or premolars) were extracted atraumatically. Immediately after guided implant insertion, the abutments were adjusted and placed according to the allocation group (0, 15, or 25-degree angle) then a temporary crown was performed out of occlusion in centric and eccentric relation. Early implant failure was assessed at three and six months. Results:There was no statistically significant difference between the two groups (P=0.305). Straight and angled abutment groups showed 6 (14.3%) and 8 (20%) failed cases, respectively. The post-hoc subgroup analysis showed no statistically significant difference between angle 15 and angle 25 degree groups where (P=0.686) or between Anterior and Premolar groups (P=0.853). Conclusion: There was no statistically significant difference in the failure rate when comparing angled to straight immediately placed & restored implants. This applies to both anterior and premolar implants

A study comparing patient satisfaction and retention of CAD/CAM milled complete dentures and 3D printed CAD/CAM complete dentures versus conventional complete dentures: a randomized clinical trial / Um estudo comparando a satisfação do paciente e a retenção de próteses totais fresadas em CAD/CAM e próteses totais 3D impressas com tecnologia CAD/CAM versus próteses totais convencionais: um ensaio clínico randomizado

Objective: To compare the three different methods of complete denture fabrication assessing patient satisfaction and retention after insertion for six months' follow-up period. Material and Methods: The study was conducted in the Prosthodontic Department where a total of forty-eight patients were recruited from the outpatient clinics fulfilling the inclusion criteria. This study was designed as a randomized controlled clinical trial. All patients followed the steps of complete denture construction till jaw relation record. Then, all eligible patients were randomized to intervention and control groups. For intervention groups digital scanning, designing, manufacturing of complete dentures was done; 3D printing for first and milling for second intervention. For the comparator group, complete dentures were manufactured the conventional way. After 2 weeks of delivery of the dentures, patients received a patient satisfaction questionnaire, retention was measured by retention force gauge. Both readings were also recorded after 3 months and at 6 months. The mean and standard deviation values were calculated for each group in each test. The significance level was set at P≤ 0.05. Results: No statistical difference was found in terms of patient satisfaction and retention between the three groups at different time intervals. Conclusion: The manufacturing technique seemed to have no influence on patient satisfaction and retention with milled showing the least results.(AU)

Objetivo: Comparar três métodos diferentes de fabricação de prótese total avaliando a satisfação do paciente e a retenção após a inserção por um período de acompanhamento de seis meses. Material e Métodos: O estudo foi conduzido no departamento de Prótese onde um total de quarenta e oito pacientes foram recrutados das clínicas ambulatoriais atendendo os critérios de inclusão. Este estudo foi designado como um ensaio clínico randomizado controlado. Todos os pacientes seguiram as mesmas etapas de confecção de prótese total até o registro da relação maxilo-mandibular. Então, todos os pacientes qualificados foram divididos de forma aleatória nos grupos de intervenção e grupo controle. Para os grupos de intervenção foram realizados escaneamento digital, projeto e fabricação de próteses totais; Impressão 3D para o primeiro e fresagem para o segundo grupo de intervenção. Para o grupo de comparação, próteses totais foram feitas com o método convencional. Depois de 2 semanas após a entrega das próteses os pacientes receberam um questionário de satisfação e a retenção foi mensurada com um medidor de força de retenção. Ambas as leituras também foram registradas após 3 e 6 meses. Os valores de média e desvio padrão foram calculados para cada grupo em cada teste. O nível de significância foi estabelecido em P ≤ 0,05. Resultados: Nenhuma diferença estatística foi encontrada em termos de satisfação do paciente e retenção entre os três grupos em diferentes intervalos de tempo. Conclusão: A técnica de fabricação pareceu não ter influência na satisfação do paciente e retenção da prótese, com o grupo fresado apresentando o mínimo de resultados.(AU)

Effect of the mycotoxin zearalenone on the testis of mice and the protective role of vitamin E: Histological and toxicological study

Zearalenone [ZEN] is a non steroidal mycotoxin produced by several species of Fusarium fungi. It is frequently detected in cereals used for human food stuffs and animal feeds such as wheat, maize and rice. Zearalenone and its metabolites constitute an important class of endocrine disruptors which causes estrogenic effects and can alter reproduction. The aim of the present work was to evaluate the histological and biochemical toxic effects of Zearalenone on the testicular tissue of mice and the possible role of vitamin E in preventing such effects. The study was carried out on forty adult male mice classified into three groups; a control group which comprised three subgroups; [negative control that received no treatment and two positive controls receiving intraperitoneal injection of either olive oil or vitamin E], ZEN-treated group where zearalenone intoxication was induced by daily intraperitoneal injection in a dose of 20 mg/kg b.wt for 3 days, while the protected group received vitamin E by intraperitoneal injection in a dose of 100 mg/kg b.wt daily for 3 days, simultaneously with zearalenone in a similar dose to that of ZEN-treated group. By the end of the experimental period, blood samples were collected for estimation of serum testosterone level. The mice were then sacrificed and fresh specimens were taken from the testis and processed for light and electron microscopic examinations. Biochemical analysis of serum testosterone demonstrated significant decrease in the hormonal level in the ZEN-treated group compared to the control group, while vitamin E-protected group revealed nearly normal levels with no significant difference from the control subgroups. Light microscopic examination of ZEN- treated group revealed loss of normal architecture of the testicular tissue as several seminiferous tubules showed disorganization of the spermatogenic cells and dissolution of the intercellular connections. Ultrastructural examination of the same group revealed many degenerated cells with electron dense cytoplasm and dense irregular nuclei, multiple apoptotic spermatogenic cells, spermatids with various degrees of degeneration and failure of acrosomal cap formation together with multiple abnormal spermatozoa with irregular heads. Extensive exfoliation of spermatids together with other degenerated cells were frequently depicted in the lumen. Many Leydig cells appeared degenerated with irregular nuclei. On the other hand, vitamin E-protected group showed amelioration of most of the degenerative changes depicted in the ZEN treated group. Exposure to the mycoloxin zearalenone demonstrated a considerable risk on the testicular structure and function of mice. Simultaneous administration of vitamin E was efficient in preventing most of such toxic effects. Therefore, mycological analysis should be regular for food stuffs especially cereals. Whereas, vitamin E can be recommended for protecion against zearalenone intoxication

comparative histological and toxicological study on the protective effect of casein versus retinol on N-Butyl Benzene sulphonamide-induced toxicity in adrenal cortex of albino rats

N-butyl benzene sulphonamide [NBBS] is a plasticizer used in production of plastic resins and as a starting agent in the synthesis of agricultural fungicides. Workers engaged in these industries and consumers of their products are at an increased risk of neurodegenerative intoxication. Nevertheless, other possible toxic effects of NBBS have not yet been studied. The aim of the study was to evaluate the possible toxic effect of NBBS on adrenal cortex of albino rats and the protective role of dietary casein versus retinol [vitamin A]. The study was conducted on forty two adult male albino rats, divided into four groups: a control group [further subdivided into; a negative subgroup receiving no treatment and three positive controls given olive oil, retinol or casein], NBBS-treated group and two protected groups receiving NBBS with either retinol or casein for 28 days. Blood samples were collected for estimation of serum corticosterone level and specimens from the adrenal cortex were processed and subjected to light and ultrastructural microscopic examination. Significant reduction of serum corticosterone level was noticed in NBBS-intoxicated group, while rats protected with casein or vitamin A showed restoration of serum corticosterone to nearly normal control values. On the other hand, light and ultrastructural examination revealed marked affection of the adrenal cortex of NBBS-intoxicated rats, with thickened connective tissue capsule and more affection of zona glomerulosa and fasiculata than zona reticularis. The pronounced feature of zona glomerulosa was hyperplasia and disorganized archades together with multiple lipid droplets and microvillous projections in some cells. Zona fasiculata showed disorganized columns. Some cells revealed excessive lipid droplets and myelin figures, while others showed nuclear pyknosis. Numerous bizarre mitochondria were demonstrated in some cells. Few cells showed disturbed mitochondrial cristae and rough endoplasmic reticulunt dilatation. Most of zona reticularis cells appeared normal, however, few cells revealed irregular nuclei and mitochondrial pleomorphism. Protection with vitamin A and casein was successful in ameliorating the biochemical and histological changes induced by NBBS, where increased serum corticosterone level was recorded approaching control values, with restoration of nearly normal histological structure of all three zones of the adrenal cortex, however casein was more effective in reversing NBBS toxic effects. The plasticizer NBBS showed significant adreno-cortical toxicity. The use of antioxidants especially casein was efficient against NBBS toxic effects. Restriction of the use of plastic packaging for foods, pharmaceuticals and other biological products is recommended to avoid leaching of plasticizers resulting in toxic exposure

Comparative histological study of the effect of static and alternating magnetic fields on the testicular tissue of albino rats

Twenty-five adult male albino rats were used in this study and divided into three groups. Group I [five rats] was used as a control and groups II and III [ten rats each] were exposed to static [direct] and alternating [time varying] EM fields [10 mT, 2 hours/day for 30 days, respectively]. At the end of the experiment, the rats were sacrificed by decapitation and specimens from the testis were taken and processed for light [H and E and trichrome stains] and electron microscopic study. The results indicated that the testis of animals of group II revealed the degeneration of peripheral seminiferous tubules affecting spermatocytes, spermatids and spermatozoa. They showed pyknotic nuclei and vacuolated cytoplasm. Leydig cells were also affected. Interstitial hyalinization and vacuolation were noticed. These changes were confirmed by ultrastructural examination, which revealed various degenerative changes in the nuclei, cytoplasm and organelles of the spermatogenic layers and Leydig cells. Fibrosis was an obvious finding seen by using trichrome stain. In group III, the same changes were observed, but in a more severe and extensive manner. A complete lysis of spermatogenic cells was observed in some tubules, which were lined only by spermatogonia and sertoli cells