Eficácia da técnica de infiltração em lesões cariosas proximais de molares decíduos: ensaio clínico controlado randomizado com 24 meses de acompanhamento / Efficacy of the infiltration technique in carious lesions proximal de molares deciduous: controlled clinical trial randomized with 24 months of follow-up

O objetivo deste ensaio clínico controlado randomizado boca-dividida foi avaliar a eficácia da técnica micro-invasiva de infiltração de cárie em lesões cariosas proximais de molares decíduos após 12 e 24 meses do tratamento, através da análise radiográfica pareada. Cinquenta crianças de 5 a 9 anos, com pelo menos 2 lesões proximais não cavitadas e extensão radiográfica atingindo 1/2 do esmalte ou 1/3 externo da dentina foram selecionadas, alocadas em grupo teste (Infiltração de resina, Icon®, DMG, Hamburgo, Alemanha) e grupo controle (dentifrício fluoretado e fio dental) e tratadas em estudo prévio. Foram elegíveis para a amostra do presente estudo os 50 pacientes que receberam a intervenção terapêutica no estudo anterior. Semestralmente os pacientes eram chamados para reforço da instrução de higiene oral e novo exame clínico odontológico e anualmente, submetidos a exame radiográfico digital. A análise radiográfica foi feita por avaliador padrão-ouro cego à alocação dos dentes (teste e controle), e aos dados clínicos dos pacientes. As diferenças entre o grupo teste e o grupo controle, em relação à progressão de lesão cariosa, foram analisadas utilizando o teste McNemar com nível de significância de 0,05. Vinte e dois pacientes compareceram à consulta de 12 meses de acompanhamento, sendo somados aos 20 pacientes já avaliados no estudo prévio, totalizando assim a amostra de 42 pacientes (42/50). Clinicamente apenas 1 lesão controle progrediu para cavitação. Radiograficamente, 11,9% das lesões teste e 33.3% das lesões controle progrediram. Em 10 pacientes apenas a lesão controle progrediu, enquanto em 1 paciente progrediu apenas a lesão teste; em 4 pacientes progrediu tanto a lesão teste como a controle (p=0,012). Outros vinte e dois pacientes (22/38), compareceram à consulta de 24 meses de acompanhamento. Clinicamente 5 lesões cavitaram (2 do grupo teste e 3 do controle). Radiograficamente, 22,7% lesões do grupo teste e 50% lesões do grupo controle e progrediram. Em 6 pacientes apenas a lesão controle progrediu, enquanto em nenhum paciente progrediu apenas a lesão teste; em 5 pacientes progrediu tanto a lesão teste como a controle (p= 0,031). O padrão de higiene bucal não mudou ao longo das revisões. O risco de cárie do paciente não influenciou no desfecho do estudo (p>0,05). A eficácia terapêutica da infiltração de resina aos 12 e 24 meses foi de 21,4% e 27,3%, respectivamente. Não foram encontrados efeitos adversos relacionados a técnica de infiltração. Pode-se concluir que a técnica de infiltração de resina é um método micro-invasivo seguro, eficaz e viável para tratamento de molares decíduos. (AU)

The purpose of this randomized controlled trial split month was evaluate the efficacy of microinvasive caries infiltration technique in proximal carious lesions in primary molars after 12 and 24 months of treatment through paired radiographic analysis. Fifty children aged 5 to 9 years, with at least two non-cavitated proximal lesions and radiographic extension involving 1/2 of the enamel or outer 1/3 of dentin were included, allocated in test group (resin infltration, Icon®, DMG, Hamburg, Germany) and control group (fluoride toothpaste and dental floss) and treated in a previous study. The 50 patients who received the therapeutic intervention in the previous study were eligible for the study sample. Patients were asked twice a year to reinforce oral hygiene instruction and a new clinical dental examination and, annually, submitted to digital radiographic examination. The radiographic analysis was done by blind gold standard evaluator to the allocation of the teeth (test and control), and to the clinical data of the patients. The differences between the test group and the control group, in relation to the progression of carious lesion, were analyzed using the McNemar test with a significance level of 0.05. Twenty-two patients attended the 12-month follow-up visit, and were added to the 20 patients already evaluated in the previous study, thus totaling the sample of 42 patients (42/50). Clinically only 1 control lesion progressed to cavitation. Radiographically, 11.9% of the test lesions and 33.3% of the control lesions progressed. In 10 patients only the control lesion progressed, whereas in 1 patient only the test lesion progressed; In 4 patients progressed both the test and control lesions (p = 0.012). Another twenty-two patients (22/38) attended the 24-month follow-up visit. Clinically, 5 lesions cavitated (2 from the test group and 3 from the control group). Radiographically, 22.7% lesions of the test group and 50% lesions of the control group and progressed. In 6 patients only the control lesion progressed, whereas in no patient only the test lesion progressed; In 5 patients progressed both the test and control lesions (p = 0.031). The standard of oral hygiene did not change throughout the reviews. The caries risk of the patient did not influence the outcome of the study (p> 0.05). The therapeutic efficacy of resin infiltration at 12 and 24 months was 21.4% and 27.3%, respectively. No adverse effects were found related to the infiltration technique. It can be concluded that the resin infiltration technique is a safe, effective and viable micro-invasive method for the treatment of deciduous molars. (AU)

A comparison of the accuracy of polyether, polyvinyl siloxane, and plaster impressions for long-span implant-supported prostheses.

PURPOSE: The purpose of this study was to compare the capacity of different impression materials to accurately reproduce the positions of five implant analogs on a master model by comparing the resulting cast with the stainless steel master model. The study was motivated by the knowledge that distortions can occur during impression making and the pouring of casts and that this distortion may produce inaccuracies of subsequent restorations, especially long-span castings for implant superstructures. MATERIALS AND METHODS: The master model was a stainless steel model with five implant analogs. The impression materials used were impression plaster (Plastogum, Harry J Bosworth), a polyether (Impregum Penta, 3M ESPE), and two polyvinyl siloxane (PVS) materials (Aquasil Monophase and Aquasil putty with light-body wash, Dentsply). Five impressions were made with each impression material and cast in die stone under strictly controlled laboratory conditions. The positions of the implants on the master model, the impression copings, and the implant analogs in the subsequent casts were measured using a coordinate measuring machine that measures within 4 µm of accuracy. RESULTS: Statistical analyses indicated that distortion occurred in all of the impression materials, but inconsistently. The PVS monophase material reproduced the master model most accurately. Although there was no significant distortion between the impressions and the master model or between the impressions and their casts, there were distortions between the master model and the master casts, which highlighted the cumulative effects of the distortions. The polyether material proved to be the most reliable in terms of predictability. The impression plaster displayed cumulative distortion, and the PVS putty with light body showed the least reliability. CONCLUSIONS: Some of the distortions observed are of clinical significance and likely to contribute to a lack of passive fit of any superstructure. The inaccuracy of these analog materials and procedures suggested that greater predictability may lie in digital technology.

Clinical safety, quality and effect of resin infiltration for proximal caries.

AIM: Resin infiltration of proximal lesions is a new approach to stop caries progression. The aim of this clinical trial was to assess its safety and quality, as well as the therapeutic effect. MATERIALS AND METHODS: In 47 children, adolescents and young adults, ten dentists applied the infiltration material ICON (DMG, Germany) on initial proximal lesions according to the manufacturer's instruction. One lesion with radiographic extension into enamel or the outer third of dentin per participant was allocated for the treatment. The clinical safety and quality of resin infiltration were assessed 1 week, 6 months and 12 months after the treatment and the evaluation of the therapeutic effect was analysed by pair-wise radiographs. RESULTS: The clinical safety and quality of the infiltration were assessed in 45 individuals after 12 months. The test surfaces showed no relevant changes in clinical status, plaque accumulation or gingival status (p > 0.05). A high quality of infiltration was found for the marginal adaptation. In contrast to the improvement of colour at the one-week recall (p = 0.005), the infiltrated surfaces showed a statistically significant increase in the discoloration within the following year (p = 0.014). Out of the 43 lesions which could be assessed radiographically, only two lesions showed progression to a different score (4.7%). CONCLUSION: Resin infiltration can be considered a safe and effective treatment to reduce progression of initial proximal caries.

Evaluation of accuracy of casts of multiple internal connection implant prosthesis obtained from different impression materials and techniques: an in vitro study.

Movement of impression copings inside the impression material using a direct (open tray) impression technique during clinical and laboratory phases may cause inaccuracy in transferring the 3-dimensional spatial orientation of implants intraorally to the cast. Consequently, the prosthesis may require corrective procedures. This in vitro study evaluated the accuracy of 3 different impression techniques using polyether and vinyl polysiloxane (VPS) impression material to obtain a precise cast for multiple internal connection implants. A reference acrylic resin model with 4 internal connection implants was fabricated. Impressions of the reference model were made using 3 different techniques and 2 different impression materials. The study consisted of 24 specimens divided into 6 groups of 4 each. Impressions were poured with ADA type IV stone (Kalrock, Kalabhai Karson Pvt Ltd, Mumbai, India). All casts were evaluated for the positional accuracy (mm) of the implant replica heads using a profile projector. These measurements were compared to the measurements calculated on the reference resin model, which served as a control. Data were analyzed with 2-way analysis of variance (ANOVA) followed by Bonferroni multiple comparison procedures to evaluate group means. The results revealed significant difference for anterior implant distance between the 2 impression materials (P < .01) and also among the 3 different techniques (P < .05). The lowest mean variation was found with the polyether impression material and the splinted technique. For posterior implants, the results suggested no significant difference between the 2 impression materials (P ≥ .05). Although results were not statistically significant, the polyether impression material showed the lowest mean variation as compared to the VPS impression material. However, there was a significant difference among the 3 different techniques (P < .05). Among the 3 different techniques, the lowest mean variation between 2 posterior implants was found in the splinted technique. Casts obtained from impression techniques using square impression copings splinted together with autopolymerizing acrylic resin prior to the impression procedure were more accurate than casts obtained from impressions with nonmodified implant impression copings and with airborne particle-abraded, adhesive-coated copings. Casts obtained from polyether impression material were more accurate than casts obtained from vinyl polysiloxane impression material.

Accuracy of three implant impression techniques with different impression materials and stones.

The purpose of this study was to compare the accuracy of casts made using three different impression techniques to obtain an accurate definitive cast for fabrication of multiple-implant prostheses. Twelve experimental groups were formed combining the following conditions: three impression techniques, two impression materials, and two cast materials. The main effects of the three factors were analyzed by three-way analysis of variance using the full factorial general linear model between factors. The results showed that there were no significant differences in mean values for the transferred dimensions between the control and experimental groups. None of the measurements in the horizontal plane of the definitive casts demonstrated significant differences among the impression techniques with different impression and cast materials (P > .01).

On the use of Kinetex(™) -C(18) core-shell 2.6 µm stationary phase to the multiclass determination of antibiotics.

Fast and accurate analysis is a prerequisite in all analytical fields especially in food, biological, pharmaceutical, and environmental samples. The new trend of ultra performance liquid chromatography (LC) has the main drawback of expensive instrumentation, which can't be easily found in low-budget analytical laboratories. The evolution of core shell technology has contributed to this direction, since ultra high efficiency can be achieved on common LC instrument platforms. Herein the novel core shell analytical column, KINETEX (™) 2.6 µm, (150 mm × 4.6 mm) was comparatively studied against two conventional reversed-phase silica-based and one monolithic column. Eight antimicrobial agents representing two different classes: penicillins and amphenicols, were separated using a typical 400 bar high performance liquid chromatography (HPLC) equipment. Comparison of column performance was carried out by calculation of the number of theoretical plates N, the tailing factor T(f) , the relative retention time RRT, the retention factor k, the resolution factor R(s) , and the precision of the retention time and peak area. Optimal chromatographic conditions were used to validate the method. Its applicability was proven by the analysis of veterinary drug formulations. The examined antibiotics were well resolved within 17 min. Limit of quantitation values were 25.9 ng for amoxicillin, 14.1 ng for ampicillin, 41.6 ng for thiamphenicol, 9.6 ng for oxacillin, 23.5 ng for florfenicol, 26.7 for cloxacillin, 23.5 ng for chloramphenicol and 42.3 ng for dicloxacillin for 20 µL injection volume. The developed method can be easily and readily transferred to any laboratory.

[Destruction of the solid-cast rubber tyres by microscopic fungi].

Resistance to the action of standard test-cultures of fungi (in accordance with GOST 9.049-91 of the former U.S.S.R.) and species, isolated from rubber substrates of two types of the poured rubber tyres, which contained natural and synthetic plasticizer, have been investigated. It has been shown that the strains, isolated from rubber materials have an ability to deteriorate rubber tyres of two types, in contrast to standard species, which caused deterioration only to the tyres, containing the synthetic plasticizer. It has been described in our investigations that fungal resistance of studied tyres decrease with time (on the 28th and 365th day, accordingly), that is shown in full overgrowing of tyre samples, in destruction of their surfaces and in changing of their hardness. Such changes are accompanied by processes of oxidation of rubber, degradation of plasticizer, and by deleaching of such inorganic components of rubber as calcium carbonate, kaolin and zeolite. This information is presented on IR-spectrograms of investigated samples as the absence or presence of absorption frequencies of different intensity that corresponded to aromatic, hydroxyl, ester, alcohol, nitrile and inorganic groups. The paper is presented in Ukrainian.

[Contamination of solid-cast rubber tires by microscopic fungi].

The main peculiarities of fungal resistance of two types of unit cast rubber tires of domestic manufacture have been investigated. Rubber tires which contained synthetic plasticizer were non-resistant to fungal contamination in contrast to ones with natural plasticizer. Using the method of confocal laser-scanning microscopy, it was shown that inner layers of two types of rubber tires were contaminated with fungal mycelium. Our findings indicate that the investigation of microscopic fungi resistance of new materials is necessary for general mechanical rubber goods, especially exported to tropical climate countries.

Effect of storage in artificial saliva and thermal cycling on Knoop hardness of resin denture teeth.

PURPOSE: This study aimed to evaluate the effect of different storage periods in artificial saliva and thermal cycling on Knoop hardness of 8 commercial brands of resin denture teeth. METHODS: Eigth different brands of resin denture teeth were evaluated (Artplus group, Biolux group, Biotone IPN group, Myerson group, SR Orthosit group, Trilux group, Trubyte Biotone group, and Vipi Dent Plus group). Twenty-four teeth of each brand had their occlusal surfaces ground flat and were embedded in autopolymerized acrylic resin. After polishing, the teeth were submitted to different conditions: (1) immersion in distilled water at 37+/-2 degrees C for 48+/-2h (control); (2) storage in artificial saliva at 37+/-2 degrees C for 15, 30 and 60 days, and (3) thermal cycling between 5 and 55 degrees C with 30-s dwell times for 5000 cycles. Knoop hardness test was performed after each condition. Data were analyzed with two-way ANOVA and Tukey's test (alpha=.05). RESULTS: In general, SR Orthosit group presented the highest statistically significant Knoop hardness value while Myerson group exhibited the smallest statistically significant mean (P<.05) in the control period, after thermal cycling, and after all storage periods. The Knoop hardness means obtained before thermal cycling procedure (20.34+/-4.45 KHN) were statistically higher than those reached after thermal cycling (19.77+/-4.13 KHN). All brands of resin denture teeth were significantly softened after storage period in artificial saliva. CONCLUSION: Storage in saliva and thermal cycling significantly reduced the Knoop hardness of the resin denture teeth. SR Orthosit denture teeth showed the highest Knoop hardness values regardless the condition tested.

Water sorption and diffusion coefficient through an experimental dental resin.

Polymeric composites have been widely used as dental restorative materials. A fundamental knowledge and understanding of the behavior of these materials in the oral cavity is essential to improve their properties and performance. In this paper we computed the data set of water absorption through an experimental dental resin blend using specimen discs of different thicknesses to estimate the diffusion coefficient. The resins were produced using Bisphenol A glycol dimethacrylate, Bisphenol A ethoxylated dimethacrylate and Triethylene glycol dimethacrylate monomers. The water sorption test method was based on International Standard ISO 4049 "Dentistry-Polymer-based filling materials". Results show a diffusion coefficient around 6.38 x 10(-8) cm(2)/s, within a variance of 0.01%, which is in good agreement with the values reported in the literature and represents a very suitable value.

Ten-year outcome of crowns placed within the General Dental Services in England and Wales.

AIM: It is the aim of this paper to consider the factors associated with the need for re-intervention on a crown, and the times to re-intervention. METHODS: A data set was established consisting of patients, 18 years or older, whose birthdays were included within a set of a randomly selected dates, one of which was chosen in each possible year of birth and whose restoration records contained the placement of one or more indirect restorations on courses of treatment with last date on the claim form after 31st December 1990, and with date of acceptance after September 1990 and before January 2002. For each tooth treated with a crown, the subsequent history of intervention on that tooth was consulted, and the next date of intervention, if any could be found in the extended data set, was obtained. Thus, a data set was created of crowns which have been placed, with their dates of placement and their dates, if any, of re-intervention. RESULTS: Data for over 80,000 different adult patients were analysed, of whom 46% were male and 54% female. A total of 47,474 crown restoration occasions were obtained from the data over a period of 11 years. Metal crowns were found to have the longest survival-68% at 10 years, and all-porcelain crowns the shortest-48% at 10 years. Factors which were found to influence outcome of crowns included type of crown, age of patient, patient payment exemption status, patient attendance pattern and placement of a root filling in the same course of treatment as a crown. CONCLUSIONS: Full-coverage all-metal crowns have longer survival times before re-intervention than metal-ceramic crowns and all-ceramic crowns. Root fillings are associated with reduced survival time of the crowns examined in this study.

Analysis of an administrative database of indirect restorations over 11 years.

AIM: This paper describes the database used to assess the survival of indirect restorations and presents general data on survival of these restorations. METHODS: Data, based on the complete attendance and treatment history, over the 11 years from 1991 to 2001, of a statistically representative sample of 23,165 General Dental Services' (GDS) patients in England and Wales, all of whom received at least one indirect restoration during the observation period, have been analysed. The patients on the database received a total of 36,397 courses of treatment, and there were 52,481 indirect restorations placed. The method of analysis involved the estimation of the probability that the patient will eventually return, given an interval without attending, by analysing the observed patterns of re-attendance. This estimated probability of re-attendance was then used to modify the standard Kaplan-Meier procedure to produce realistic estimates of the hazard of re-intervention. RESULTS: Overall, 75% of indirect restorations remained without re-intervention after 5 years, and 61% after 10. Crowns outperformed other types of indirect restoration. Multi-surface metal inlays, by contrast, had a median interval to re-intervention of less than 8 years. CONCLUSIONS: The times to re-intervention for different types of indirect restoration have been successfully estimated and crowns shown to outperform veneers and inlays.

Polyimide tubing: dispelling the myths.

The capabilities and potential of polyimide and polyimide tubing are gaining popularity in the medical design market place as a result of the increasing need for minimally invasive surgical devices. This article looks at the myths surrounding the tubing to better understand its advantages for medical applications.

[Research advances of macroporous resin].

We surveyed the literatures domestic and abroad, and summarized the physical and chemical characterizations as well as preparation and applications of macroporous resin. The research of physical parameter and chemical parameter includes the measurement of the organic residue, the application research includes the separation and purification methods of the phytochemical ingredients. Macroporous resin show its advantages in the field of phytochemical studies, traditional Chinese medicine development and production, but there exist some disadvantages in its performance and application. It's necessary to establish the quality standard and the technical specifications to promote the standardization of the research and the application of the macroporous resin.

Polystyrene derivatives as candidates for extracorporeal adsorption of Factor VIII antibodies in the management of haemophiliac patients.

BACKGROUND AND OBJECTIVES: This article presents a new approach for removing the Factor VIII inhibitors (anti-FVIII) in haemophiliac patients by immunoadsorption using an affinity matrix. MATERIALS AND METHODS: Ten blood samples from haemophiliac patients with anti-FVIII were assayed for antibodies, total immunoglobulins, procoagulant proteins and complement C3 protein after circulation over one or two columns filled with the polymers under investigation. RESULTS: These new synthetic sorbents are able to remove in vitro 90% of anti-FVIII from haemophiliac plasma with inhibitors (up to 540 Bethesda Units/ml). Neither coagulation factor adsorption nor effects on complement system activation were observed. CONCLUSIONS: The data presented clearly show that these polymers allow a rapid and efficient reduction of inhibitor titre. In view of the parameters studied, these polymers fulfil the requirements for use in a blood purification process to decrease high inhibitor titres without losing essential proteins.

Optimization of reaction conditions for REM resin-bound quaternization reactions.

A study into the effect of reaction variables on the quaternization of REM resin-bound tertiary amines was undertaken. The influence of resin matrix, solvent, reaction time, temperature, and amount of quaternization agent on the outcome of reaction was evaluated by reaction monitoring using (19)F NMR. The highest yields of tertiary amine products were seen when DMSO was used as reaction solvent in conjunction with a reaction time of 18 h at room temperature. The use of heating for extended reaction times tended to depress yields, indicating product cleavage during quaternization. Quaternization on PS-DVB resin was found to be more robust than reaction on PS-PEG matrices where yields were generally considerably lower than the observed conversions. DMSO was the most efficient reaction solvent for both resins despite poor swelling of the quaternization starting material.

Comparative resin kinetics using in situ fluorescence measurements.

The aminolysis of a novel activated ester resin was utilized for kinetic study via continuous in situ fluorescence measurements. A variety of resin compositions (polystyrene, JandaJel, ArgoPore, TentaGel, NovaGel, and PEGA) and solvents (dimethylformamide, acetonitrile, tetrahydrofuran, 1,2-dichlorethane, and toluene) were tested to compare their effects on the reaction rate. A linear relationship between the reaction rate and (solvent polarity x swelling of resin) was elucidated for the aminolysis reaction.

Influence of dimensional stability of impression materials on the probability of acceptance of a prosthetic restoration.

The accuracy of rubber impression materials was evaluated by taking impressions of a steel model, pouring it with stone and comparing certain measurements between steel and stone models. It is assumed that acceptance is achieved when the difference in measurements is within permissible limits, defined by clinical criteria. A mathematical formulation of these criteria will lead to the concept of probability of acceptance. The probability is affected when the limits are changed. The particular case of satisfying two acceptance criteria that contain variables which are not statistically independent is considered, leading to the application of the bivariate normal distribution in the evaluation of acceptance probability.

[Toxicological and hygienic studies of a new polymer glue to be used in shoe-making industry]. / Toksikologo-gigienicheskie issledovanniia novogo polimernogo kleia, predlagaemogo dlia primeneniia v obuvnoi promyshlennosti.

Toxico-hygienic studies have been carried out of a new polymeric glue to be used in the shoe-making industry. As a result of studies the use of the glue is recommended in the shoe-making industry, conditions of its safe use and the way to maintain current sanitary supervision have been suggested.

Quality evaluation of anterior restorations in private practice.

As part of a series of postgraduate courses in Cariology for dentists, a section designed to stimulate the interest in quality evaluation of fillings was included. Thus, 75 private practitioners were asked to evaluate a number of anterior restorations on their own patients. The method used was a modification of the California Dental Association (CDA) quality evaluation system. By use of a four-graded scale the following five properties were evaluated: (1) color of the filling, (2) color of the margin, (3) surface structure and anatomic form, (4) marginal integrity, and (5) caries. The criteria were related to practical-clinical measurements. Altogether 1147 fillings were assessed, most of them 2-4 years old (n = 949). The results showed that 25 different brands had been used, of which 4 composites constituted 68% of all fillings. With the exception for one composite material, no obvious difference in the quality evaluation between the materials was observed. Of the 2-4 year old fillings, approximately every fourth was rated as "not acceptable", i.e. with need for clinical treatment "soon" or "within reasonable time". Our impression was that the system used in this study is suitable for an assessment of the quality of anterior fillings in a private practice and that it should stimulate dentists to a quality thinking in dentistry in general.