How do implant patients experience complications? A cross-sectional multicentre pilot study.

BACKGROUND: This cross-sectional study aimed to quantify the impact of implant-related complications on perceived pain, functional impairment, concern, quality of life (QoL) and confidence which were the study's primary outcomes. MATERIALS AND METHODS: Patients were recruited in five centres over 19 months. They completed a structured ad hoc questionnaire scoring pain, chewing ability, concern, QoL and confidence in future implant treatment. Some potential independent variables were also recorded. The data were analysed descriptively and with a multiple-stepwise regression model for correlations of the five primary variables with the other data. RESULTS: The sample consisted of 408 patients, with prosthesis mobility being the most common complication (40.7%). Most patients (79.2%) consulted because of a complication, while 20.8% were asymptomatic and consulted regularly. Pain was correlated with symptoms at consultation and in biological/mixed complications (p < .001; R2 = 44.8%). Chewing impairment with implant loss, prosthesis fracture and removable implant-supported or total prostheses (p < .001; R2 = 42.8%); patient concern was correlated with the clinical symptoms and removable implant-supported prostheses (p < .001; R2 = 36.1%); impact on QoL was correlated with implant loss, prosthesis fracture and removable implant-supported prostheses (p < .001; R2 = 41.1%). Patient confidence was relatively independent and only impact on quality of life significantly influenced it (r = 0.73). CONCLUSIONS: Implant-related complications moderately impaired patients' perceptions of pain, chewing ability, concern and QoL. Nevertheless, complications only slightly reduced their confidence in future implant treatment.

Is Inferior Alveolar Nerve Block Needed to Perform Implant Surgery in the Posterior Mandible? A Randomized Controlled Trial.

PURPOSE: There is no agreement in the literature on whether inferior alveolar nerve block (IANB) or infiltration (INF) is the anesthetic technique of choice for placing implants in the posterior mandible. This study aimed to compare the efficacy of the 2 techniques using articaine 4% with epinephrine 1:100,000. MATERIAL AND METHODS: The trial was a comparison between 2 parallel groups of patients, who received implants distal to the mental foramen, either with IANB or INF. The anesthetic technique was the predictor variable. The primary outcome was patients' perceived pain by a numerical rating scale (NRS) in incision, osteotomy and suture. The secondary outcome, patients' satisfaction, was equally recorded 12 hours after surgery. The dataset were first analyzed by descriptive statistics. Then, Mann-Whitney test, Spearman's coefficient, and regression models were used. This trial followed the recommendations of the Consort Statement for reporting randomized controlled trials (RCTs). RESULTS: Ninety-six patients (41 men, 55 women, mean age 55.76 years) were randomly assigned to either group, IANB or INF, of 48 patients each. Only 20% of patients reported pain values >0 (range 0-4 of 10). Medians were: 0 (0-0) for both groups (P = .956, .175 and .908, incision, osteotomy and suture, respectively). Mean satisfaction was high in both groups, 9.0 ± 1.0, median 10; and 8.8 ± 1.7, median 9, for IANB and INF (P = .695). Hence, the anesthetic technique did not generate statistically significant differences. Five potential influencing variables that were measured did not significantly affect pain levels or patient satisfaction in either group. CONCLUSIONS: According to the results, an IANB might not be necessary for standard implant surgery in the posterior mandible, and infiltration of articaine 4% with epinephrine 1:100,000 appears to be sufficient. Further research is needed to check if these results are extensible to other anesthetic drugs.

Effects of two low-shrinkage composites on dental stem cells (viability, cell damaged or apoptosis and mesenchymal markers expression).

To investigate the effects of new two low-shrinkage composites SDR(®) and Venus(®)Bulk Fill on the cell viability, cellular damage and expression of mesenchymal markers on dental stem cells. Specimens from two low-shrinkage composites were eluted with culture medium for 24 h. After 24 h of incubation, cytotoxicity of elutes were evaluated by MTT assay; apoptosis was determined using the DNA-specific fluorochrome Hoechst 33342 and the mesenchymal stem cells markers expression was analyzed by immunofluorescence staining. After 24 h of cell exposure to each extract media, dental stem cells expressed MSCs markers. The interaction among the material and cell line was not significantly correlated [F(1,60) = 2.251, P = 0.39], whereas statistically significant differences among cells lines were observed [F(1,60) = 9.157, P = 0.004], being dental pulp stem cells more resistant that periodontal ligament stem cells. Also, we did not find any significant effect between the tested materials [F(1,60) = 0.090, P = 0.765]. Furthermore, a very low proportion of exposed cells showed condensed or fragmented nuclei, typical of apoptotic cells at 24 h. The results suggest that SDR(®) and Venus(®) Bulk fill and should be considered when selecting an appropriate resin-based dental restorative material.

In vitro behaviour of adult mesenchymal stem cells seeded on a bioactive glass ceramic in the SiO(2)-CaO-P(2)O(5) system.

This work describes the evaluation of a glass ceramic (55S41C4P-1300) as a potential substrate for bone tissue engineering. For that purpose, the capacity of mesenchymal stem cells (MSCs), isolated from rabbit bone marrow, to adhere, proliferate and differentiate into osteoblast (OBs) with or without 55S41C4P-1300 was investigated. Two types of culture medium, i.e. growth medium (GM) and osteogenic medium (OM), were evaluated. The bioactive 55S41C4P-1300, containing pseudowollastonite, wollastonite, tricalcium phosphate and crystoballite as crystalline phases, was obtained by heat treatment of a sol-gel glass (55SiO(2), 41CaO, 4P(2)O(5) (mol.%)) at 1300 degrees C. The results showed that the MSCs adhered, spread, proliferated and produced mineralized extracellular matrix on 55S41C4P-1300 regardless of the culture medium used. As the same time, they showed an osteoblastic phenotype, and this phenomenon was accompanied by the gradual diminution of the marker CD90 expression. The 55S41C4P-1300 was able to induce the differentiation of MSCs into OBs in the same way as OM without glass ceramic. This effect increased with the combination of 55S41C4P-1300 with OM. The glass ceramic evaluated in this work is bioactive, cytocompatible and capable of promoting the differentiation of MSCs into OBs. For that reason, it could be regarded as a suitable matrix in tissue engineering for bone tissue regeneration.

Cinética de crecimiento in vitro de osteoblastos humanos sobre cerámica porosa de hidroxiapatita / In vitro growth kinematics of human osteoblasts on porous hydroxyapatite ceramics

Objetivo. Estudio de la respuesta in vitro de osteoblastos humanos frente a una cerámica porosa de hidroxiapatita para su consideración como matriz en ingeniería tisular. Material y método. Se han aislado caracterizado y cultivado osteoblastos humanos. Se sembraron sobre discos del material y sobre plástico (control) y se ha estudiado mediante técnica de reducción de la sal de tetrazolio su adherencia, extensión y proliferación. Se comprobó sus características funcionales, determinando la producción de fosfatasas alcalinas, osteocalcina, colágeno I y mineralización in vitro. Resultados. Las células se adhirieron y crecieron sobre la superficie del material, y en el interior de los poros. A las 24 horas se adhirieron el 20% de las células sembradas, mientras que en el control lo hicieron el 95%, además, se observó un crecimiento más lento. La producción de fosfatasas alcalinas, osteocalcina y colágeno I por las células que crecieron sobre la cerámica fue positiva y en similar rango que los controles. Conclusiones. Los osteoblastos colonizaron la cerámica de forma más lenta que el control, mantuvieron su fenotipo y produjeron matriz extracelular. El ensayo de reducción de las sales de tetrazolio (XTT) fue satisfactorio para cuantificar la proliferación de osteoblastos sobre la cerámica. El modelo utilizado permite cuantificar y observar la funcionalidad in vitro de osteoblastos en respuesta a cerámicas de hidroxiapatita. En función de los resultados obtenidos el material utilizado en el estudio puede ser considerado, en el campo de la ingeniería tisular, como una matriz adecuada para soportar el crecimiento de osteoblastos humanos

Purpose. To study the in vitro response of human osteoblasts when in contact with porous hydroxyapatite ceramics, with a view to considering them a matrix for tissue engineering. Materials and methods. Human osteoblasts were isolated, characterized and cultured. They were seeded onto discs made of HA and onto a plastic material (control) and their adhesiveness, extension and proliferation were studied by means of a tetrazolium salt reduction test. Their functional characteristics were examined in order to determine the production of alkaline phosphatases, osteocalcin, collagen I as well as in vitro mineralization. Results. The cells adhered to and grew onto the material's surface and inside its pores. Within 24 hours, 20% of seeded cells had adhered; in the control group this percentage was 95% and the growth was slower. The cells growing onto the ceramics were found to produce alkaline phosphatases, osteocalcin and collagen in amounts similar to those in the control group. Conclusions. Osteoblasts colonized the ceramics at a lower pace than plastic; they also retained their phenotype and generated extracellular matrix. The tetrazolium salt reduction test served the purpose of validating the proliferation of osteoblasts on the ceramics. The model used makes it possible to quantify and observe the in vitro functionality of osteoblasts in their response to hydroxyapatite ceramics. On the basis of the results obtained, the material used in the study can be considered, in the field of tissue engineering, a suitable matrix to support the growth of human osteoblasts

Effects of various antineoplastic agents on an established human melanoma cell line (G-361).

An established human melanoma cell line was treated with several concentrations of three antineoplastic drugs: melphalan (0.016, 0.032, 0.16 microns), CCNU (1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea) (0.04, 0.21, 0.42 microM), and 4-OHA (4-hydroxyanisole) (4.01 x 10(-4), 1.20 x 10(-3), 2.4 x 10(-3) microM), and the effects on cell growth and viability were compared. 24 hours after treatment, 4-OHA (ID50 = 2.4 x 10(-3) microM) was more cytotoxic than melphalan (ID50 = 0.016 microM) and CCNU (ID50 = 0.21 microM). However, after 96 hours exposure, the most effective drug was CCNU (growth rate = -1.277), which caused the death of the culture. This was followed by melphalan (growth rate = -1.024) and finally 4-OHA (growth rate = -0.69). Similar ultrastructural cell injuries were observed after the use of the three drugs: the dilation of endoplasmic reticulum vesicles and the nuclear membrane; mitochondria swelling; and the existence of lamellar structures and cytoplasmic vacuoles.