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Evaluation of the dental structure loss produced during maintenance and replacement of occlusal amalgam restorations

SARDENBERG, Fernanda; BONIFÁCIO, Clarissa Calil; BRAGA, Mariana Minatel; IMPARATO, José Carlos Pettorossi; MENDES, Fausto Medeiros
Fonte: Sociedade Brasileira de Pesquisa Odontológica Publicador: Sociedade Brasileira de Pesquisa Odontológica
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
58.428325%
The aim of this in vitro study was to evaluate four different approaches to the decision of changing or not defective amalgam restorations in first primary molar teeth concerning the loss of dental structure. Ditched amalgam restorations (n = 11) were submitted to four different treatments, as follows: Control group - polishing and finishing of the restorations were carried out; Amalgam group - the ditched amalgam restorations were replaced by new amalgam restorations; Composite resin group - the initial amalgam restorations were replaced by composite resin restorations; Flowable resin group - the ditching around the amalgam restorations was filled with flowable resin. Images of the sectioned teeth were made and the area of the cavities before and after the procedures was determined by image analysis software to assess structural loss. The data were submitted to ANOVA complemented by the Student Newman Keuls test (p < 0.05). The cavities in all the groups presented significantly greater areas after the procedures. However, the amalgam group showed more substantial dental loss. The other three groups presented no statistically significant difference in dental structure loss after the re-treatments. Thus, replacing ditched amalgam restorations by other similar restorations resulted in a significant dental structure loss while maintaining them or replacing them by resin restorations did not result in significant loss.

Longevidade de restaurações posteriores de resina composta e suas principais causas de falha; Longevity of posterior composite resin restorations and their main causes of failure

Berwanger, Carolina dos Santos
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Trabalho de Conclusão de Curso Formato: application/pdf
POR
Relevância na Pesquisa
58.63746%
O aumento do uso de resinas compostas em restaurações de dentes posteriores e o aperfeiçoamento tecnológico desse material nas últimas décadas trazem aos profissionais e aos pacientes o questionamento quanto à durabilidade deste tratamento. Diversos fatores podem interferir no sucesso de uma restauração direta. Estes fatores podem estar relacionados ao material restaurador utilizado, ao dentista que realiza o procedimento e à técnica restauradora utilizada. Além disso, fatores relacionados ao paciente – como seus hábitos de higiene oral, dieta, disponibilidade de flúor e seu risco em desenvolver lesões de cáries – também podem determinar o sucesso ou o fracasso do tratamento restaurador. Deste modo, para que o sucesso da terapia restauradora seja alcançado, é importante que seja considerada a experiência clínica do profissional, hábitos do paciente e facilidade da técnica ao escolher o material restaurador. Este trabalho tem como objetivo apresentar uma revisão de literatura analisando a longevidade de restaurações posteriores de resina composta e suas principais causas de falha.; The increase in the use of composite resin in posterior teeth restorations and technological improvements of this material in recent decades made professionals and patients questions about the durability of this treatment. Several factors may affect the success of a direct restoration. These factors may be related to the restorative material...

Experimental peri-implant tissue breakdown around different dental implant surfaces: Clinical and radiographic evaluation in dogs

Martins, Marilia Compagnoni; Abi-Rached, Ricardo Samih Georges; Shibli, Jamil Awad; Araujo, Marcelo Werneck Barata; Marcantonio Jr., Elcio
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 839-848
ENG
Relevância na Pesquisa
58.11624%
Purpose: Tissue reactions to 4 different implant surfaces were evaluated in regard to the development and progression of ligature-induced peri-implantitis. Materials and Methods: In 6 male mongrel dogs, a total of 36 dental implants with different surfaces (9 titanium plasma-sprayed, 9 hydroxyapatite-coated, 9 acid-etched, and 9 commercially pure titanium) were placed 3 months after mandibular premolar extraction. After 3 months with optimal plaque control, abutment connection was performed. Forty-five days later, cotton ligatures were placed around the implants to induce peri-implantitis. At baseline and 20, 40, and 60 days after placement, the presence of plaque, peri-implant mucosal redness, bleeding on probing, probing depth, clinical attachment loss, mobility, vertical bone loss, and horizontal bone loss were assessed. Results: The results did not show significant differences among the surfaces for any parameter during the study (P > .05). All surfaces were equally susceptible to ligature-induced peri-implantitis over time (P < .001). Correlation analysis revealed a statistically significant relationship between width of keratinized tissue and vertical bone loss (r 2 = 0.81; P = .014) and between mobility and vertical bone loss (r 2 = 0.66; P = .04)...

The effect of CO 2 laser irradiation on failed implant surfaces

Shibli, Jamil Awad; Theodoro, Letícia Helena; Haypek, Patricia; Garcia, Valdir Gouveia; Marcantonio Jr., Elcio
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 342-351
ENG
Relevância na Pesquisa
48.31727%
The aim of this investigation was to evaluate the cleaning effect of CO 2 on surface topography and composition of failed dental implant surfaces. Ten failed dental implants were retrieved from nine patients (mean age, 46.33 ± 5.81 years) as a result of early or late failure. The implants were divided into two parts: one side of the implant was irradiated with a CO 2 laser (test side), while the other side did not receive irradiation (control side). The CO 2 laser was operated at 1.2 W in a continuous wave for 40 seconds (40 J energy). The handpiece of the CO 2 laser was kept at a distance of 30 mm from the implant surface, resulting in a spot area of 0.031415 cm 2 (38.20 W/cm 2; 1559 J/cm 2) in scanning mode (cervical-apical). One unused dental implant was used as a negative control for both groups. All implant surfaces were examined by scanning electron mi croscopy (SEM) and energy-dispersive spectrometer x-ray (EDS) for element analysis. SEM showed that the surface of the test sides consisted of different degrees of organic residues, appearing mainly as dark stains similar to those observed on the control sides. None of the test surfaces presented alterations such as crater-like alterations, lava-like layers, or melting compared with the nonirradiated surfaces. Foreign elements such as carbon...

Interleukin-2 and interleukin-6 gene promoter polymorphisms, and early failure of dental implants

Campos, Maria Isabela Guimarães; Godoy Dos Santos, Maria Cristina Leme; Trevilatto, Paula Cristina; Scarel-Caminaga, Raquel Mantuaneli; Bezerra, Fabio Jose; Line, Sergio Roberto Peres
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 391-398
ENG
Relevância na Pesquisa
58.436426%
Single nucleotide polymorphisms in the promoter region of the human interleukin (IL)-2 (T-330G) and IL-6 (G-174C) genes have modified the transcriptional activity of these cytokines and are associated with several diseases. The aim of this study was to investigate the possible relationship between these single nucleotide polymorphisms and early implant failure. A sample of 74 nonsmokers was divided into 2 groups: test group comprising 34 patients (mean age 49.3 years) with ĝ‰¥1 implants that failed and control group consisting of 40 patients (mean age 43.8 years) with ĝ‰¥1 healthy implants. Genomic deoxyribonucleic acid from oral mucosa was amplified by polymerase chain reaction and analyzed by restriction fragment length polymorphism. Monte Carlo simulations (P < 0.05) were used to assess differences in allele and genotypes frequencies of the single nucleotide polymorphisms between the 2 groups. No significant differences were observed in the allele and genotypes distribution of both polymorphisms when the 2 groups were compared. The results indicate that polymorphisms in the IL-2 (T-330G) and IL-6 (G-174C) genes are not associated with early implant failure, suggesting that the presence of those single nucleotide polymorphisms does not constitute a genetic risk factor for implant loss in the studied population. Copyright © 2005 by Lippincott Williams & Wilkins.

Effect of surface treatments on the bond strength of a resin cement to commercially pure titanium

de Almeida-Júnior, Antonio Alves; Fonseca, Renata Garcia; Haneda, Isabella Gagliardi; Abi-Rached, Filipe de Oliveira; Adabo, Gelson Luis
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 111-116
ENG
Relevância na Pesquisa
48.852627%
Investigation of the effectiveness of surface treatments that promote a strong bond strength of resin cements to metals can contribute significantly to the longevity of metal-ceramic restorations. This study evaluated the effect of surface treatments on the shear bond strength (SBS) of a resin cement to commercially pure titanium (CP Ti). Ninety cast CP Ti discs were divided into 3 groups (n=30), which received one of the following airborne-particle abrasion conditions: (1) 50 μm Al2O3 particles; (2) 30 μm silica-modified Al2O3 particles (Cojet Sand); (3) 110 μm silica-modified Al2O3 particles (Rocatec). For each airborne-particle abrasion condition, the following post-airborne-particle abrasion treatments were used (n=10): (1) none; (2) adhesive Adper Single Bond 2; (3) silane RelyX Ceramic Primer. RelyX ARC resin cement was bonded to CP Ti surfaces. All specimens were thermally cycled before being tested in shear mode. Failure mode was determined. The best association was Rocatec plus silane. All groups showed 100% adhesive failure. There were combinations that promote higher SBS than the protocol recommended by the manufacturer of RelyX ARC.

Clinical fractures of veneered zirconia single crowns

Almeida Júnior, Antonio A.; Munõz-Chaves, Oscar Fernando; Galvão, Beatriz Regalado; Adabo, Gelson Luis
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 17-21
ENG
Relevância na Pesquisa
48.674297%
Crowns made from an yttria-stabilized tetragonal zirconia polycrystals (3Y-TZP) core with a porcelain veneer have shown high clinical failure rates. Manifestations of clinical failure in veneering ceramic ranges from a single chip to an extended fracture. Core failures are uncommon but usually are catastrophic. This article examines the possible causes of failure in zirconia systems and presents a case report involving the diagnosis and repair of three different types of failure in six 3Y-TZP/porcelain crowns.

Evaluation of the dental structure loss produced during maintenance and replacement of occlusal amalgam restorations

Sardenberg,Fernanda; Bonifácio,Clarissa Calil; Braga,Mariana Minatel; Imparato,José Carlos Pettorossi; Mendes,Fausto Medeiros
Fonte: Sociedade Brasileira de Pesquisa Odontológica - SBPqO Publicador: Sociedade Brasileira de Pesquisa Odontológica - SBPqO
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2008 EN
Relevância na Pesquisa
58.428325%
The aim of this in vitro study was to evaluate four different approaches to the decision of changing or not defective amalgam restorations in first primary molar teeth concerning the loss of dental structure. Ditched amalgam restorations (n = 11) were submitted to four different treatments, as follows: Control group - polishing and finishing of the restorations were carried out; Amalgam group - the ditched amalgam restorations were replaced by new amalgam restorations; Composite resin group - the initial amalgam restorations were replaced by composite resin restorations; Flowable resin group - the ditching around the amalgam restorations was filled with flowable resin. Images of the sectioned teeth were made and the area of the cavities before and after the procedures was determined by image analysis software to assess structural loss. The data were submitted to ANOVA complemented by the Student Newman Keuls test (p < 0.05). The cavities in all the groups presented significantly greater areas after the procedures. However, the amalgam group showed more substantial dental loss. The other three groups presented no statistically significant difference in dental structure loss after the re-treatments. Thus, replacing ditched amalgam restorations by other similar restorations resulted in a significant dental structure loss while maintaining them or replacing them by resin restorations did not result in significant loss.

Repair of amalgam restorations with conventional and bonded amalgam: an in vitro study

Popoff,Daniela Araújo Veloso; Gonçalves,Fabiana Santos; Ferreira,Raquel Conceição; Magalhães,Cláudia Silami; Moreira,Allyson Nogueira; Mjör,Ivar A
Fonte: Pontifícia Universidade Católica do Rio Grande do Sul Publicador: Pontifícia Universidade Católica do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2010 EN
Relevância na Pesquisa
48.4381%
PURPOSE: This study evaluated microleakage on amalgam restorations repaired by amalgam and bonded amalgam. METHODS: Thirty extracted human pre-molars were restored by amalgam. A simulated defect was prepared and assigned to two treatment groups (n=15): G1 - repaired by amalgam (Permite C-SDI); G2 - repaired by bonded amalgam (Caulk 34% Tooth Conditioner Gel - Dentsply + Prime & Bond 2.1 - Dentsply + Permite C- SDI). The teeth were immersed in a 50% silver nitrate solution, thermocycled and then, sectioned longitudinally through the restoration center and examined by 3 examiners using a stereomicroscope. Microleakage was evaluated in a 0-4 scale for dye penetration. Microleakage data were analyzed by Kruskal Wallis and Dunn test. RESULTS: The bonded amalgam technique was significantly the most effective in repair/tooth interfaces sealing (score 0=53.3%, P=0.0012). For repair/restoration interfaces, conventional amalgam was also statistically more effective in the sealing (score 0=86.7%, P<0.001). CONCLUSION: None of materials eliminated microleakage completely. The use of adhesive systems had significant effect on the ability to seal the repair/tooth interface, however, for repair/restoration interface, it can increase microleakage.

Relation between bruxism and dental implants

TORCATO,Leonardo Bueno; ZUIM,Paulo Renato Junqueira; BRANDINI,Daniela Atili; FALCÓN-ANTENUCCI,Rosse Mary
Fonte: Faculdade São Leopoldo Mandic Publicador: Faculdade São Leopoldo Mandic
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2014 EN
Relevância na Pesquisa
58.02995%
OBJECTIVE: The aim of this study was to gather information and discuss the predictability of implant-supported prostheses in patients with bruxism by performing a literature review. METHODS: In order to select the studies included in this review, a detailed search was performed in PubMed and Medline databases, using the following key words: bruxism, dental implants, implant supported prosthesis, and dental restoration failure. Items that were included are: case reports, randomized controlled trials, in vitro studies, literature and systematic reviews, with or without meta-analysis, of the last 20 years that addressed the theme. Articles without abstracts, animal studies, articles in languages other than English and articles from journals unrelated to the dental field were excluded. RESULTS: after analysis according to inclusion and exclusion criteria, 28 articles were selected from a total of 54. It is known from the array of scientific articles which have assessed, either through retrospective, prospective or experimental studies, that the biomechanical and biological impact of bruxism on implant-supported prostheses is small, and that the literature has contributed little to exemplify the prosthetic limits of safety for the specialist from a clinical point of view. CONCLUSION: Although there is still no general consensus on this matter...

Novel dental adhesive containing antibacterial agents and calcium phosphate nanoparticles

Melo, Mary Anne S.; Cheng, Lei; Weir, Michael D.; Hsia, Ru-ching; Rodrigues, Lidiany K. A.; Xu, Hockin H. K.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
48.33025%
Secondary caries remains the main reason for dental restoration failure. Replacement of failed restorations accounts for 50-70% of all restorations performed. Antibacterial adhesives could inhibit biofilm acids at tooth-restoration margins, and calcium phosphate (CaP) ions could remineralize tooth lesions. The objectives of this study were to: (1) incorporate nanoparticles of silver (NAg), quaternary ammonium dimethacrylate (QADM), and nanoparticles of amorphous calcium phosphate (NACP) into bonding agent; and (2) investigate their effects on dentin bonding and microcosm biofilms. An experimental primer was made with pyromellitic glycerol dimethacrylate (PMGDM) and 2-hydroxyethyl methacrylate (HEMA). An adhesive was made with bisphenol-A-glycerolate dimethacrylate (BisGMA) and triethylene glycol dimethacrylate (TEGDMA). NAg was incorporated into primer at 0.1wt%. The adhesive contained 0.1% NAg and 10% QADM, and 0-40% NACP. Incorporating NAg into primer and NAg-QADM-NACP into adhesive did not adversely affect dentin bond strength (p>0.1). SEM showed numerous resin tags, and TEM revealed NAg and NACP in dentinal tubules. Viability of human saliva microcosm biofilms on primer/adhesive/composite disks was substantially reduced via NAg and QADM. Metabolic activity...

Three-Year Clinical Performance of Composite Restorations Placed by Undergraduate Dental Students

Moura, Fl??vio Renato Reis de; Romano, Ana Regina; Lund, Rafael Guerra; Piva, Evandro; Rodrigues J??nior, Sinval Adalberto; Demarco, Fl??vio Fernando
Fonte: Dental Foundation of Ribeir??o Preto Publicador: Dental Foundation of Ribeir??o Preto
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
48.447017%
This retrospective study evaluated the clinical performance and the reasons for failure of anterior and posterior composite restorations placed by undergraduate dental students over a 3-year period. All cavities were restored using Prime & Bond 2.1 and TPH (Dentsply), according to the manufacturer???s indications. One hundred and two patients who had received composite restorations by third and forth year undergraduate students were recalled and examined to analyze the quality of the restorations. The restorations were evaluated using the modified USPHS system. Two hundred and fifty-six composite storations, 170 in anterior teeth and 86 in posterior teeth, were evaluated. Eighty-five percent of the restorations were considered satisfactory after 3 years. Class II and class IV restorations presented the highest prevalence of failure. Loss of the estoration and deficient marginal adaptation were the main causes of failure. No restoration failed due to secondary aries. Most restorations placed by dental tudents were considered satisfactory after long-term evaluation. Failure was more revalent in larger restorations and was not associated with secondary caries.

Review of bonded amalgam restorations, and assessment in a general practice over five years

Smales, R.; Wetherell, J.
Fonte: Operative Dentistry Inc Publicador: Operative Dentistry Inc
Tipo: Artigo de Revista Científica
Publicado em //2000 EN
Relevância na Pesquisa
48.87764%
This study reviewed the literature on bonded amalgam restorations and assessed the failure, marginal fracture and marginal staining behavior of 366 Permite C amalgam restorations lined with five dentin bonding resins (Scotchbond 2, Panavia Ex, Amalgambond, Amalgambond Plus, Geristore) and a polyamide cavity varnish (Barrier). The restorations were placed in the posterior permanent teeth of 190 adult patients and examined at intervals over periods of up to five years. There were five restoration failures (1.4%), usually from tooth fracture, involving Class II preparations in molar teeth. No instances of persistent pulpal sensitivity or recurrent caries were reported. The marginal deterioration of the restorations was assessed indirectly using photographs for comparison with two standard sets of enlarged color transparencies. Most of the marginal fracture and marginal staining scores were low, with little difference between the six lining materials at any period.

Provision of diagnostic and preventive services in general dental practice

Brennan, D.; Spencer, A.
Fonte: F D I World Dental Press Ltd Publicador: F D I World Dental Press Ltd
Tipo: Artigo de Revista Científica
Publicado em //2003 EN
Relevância na Pesquisa
68.66005%
Objective: Diagnosis and prevention are among the most frequently provided services in Australian private general dental practice, and have increased over recent times. The aims of this study were to examine the provision of examinations, radiographs, prophylaxis and topical fluoride, and to assess whether these services varied by patient, visit and oral health characteristics. Basic Research Design: Data were collected by a mailed survey of a random sample of dentists from each State/Territory in Australia in 1998-99 with a response rate of 71%. Main Outcome Measures: Data were collected from a log of service items provided on a typical day. Results: Multivariate analyses of services showed that emergency visits were associated with higher rates [RR = Rate ratio, 95%CI] of radiographs (RR = 1.32, 1.06-1.66) but lower rates of prophylaxis (RR = 0.37, 0.29-0.48) and topical fluoride (RR = 0.20, 0.08-0.47) compared to non-emergency visits. Capital city patients had a higher rate of topical fluoride (RR = 2.06, 1.17-3.64) services than non-capital city patients. Patients with decayed teeth had a lower rate of prophylaxis services (RR = 0.82, 0.68-0.99) than patients with no decay. Compared to the reference of caries, patients with aesthetic problems had lower rates of radiographs (RR = 0. 19...

The nature and frequency of bisphosphonate-associated osteonecrosis of the jaws in dental implant patients: A South Australian case series

Goss, A.; Bartold, P.; Sambrook, P.; Hawker, P.
Fonte: W B Saunders Co Publicador: W B Saunders Co
Tipo: Artigo de Revista Científica
Publicado em //2010 EN
Relevância na Pesquisa
68.613955%
PURPOSE: To determine the number of bisphosphonate-associated cases of dental implant failure in South Australia. MATERIALS AND METHODS: All general and specialist dentists who place dental implants in South Australia were contacted and asked to provide information on the total number of implants placed over the decade to December 2007. Cases of bisphosphonate-associated implant failure were identified. RESULTS: All 46 practitioners involved in implant placement and the management of bisphosphonate-associated osteonecrosis of the jaws in South Australia were identified. Approximately 28,000 implants had been placed in 16,000 patients. We identified 7 cases of oral bisphosphonate-associated implant failure, with 3 cases of failure of osseointegration and 4 cases of successful implants losing integration after being placed on oral bisphosphonates. There were 5 women and 2 men, and the mean age was 65.7 years (range, 49-75 years). Only 1 was medically compromised, with steroids and diabetes. No cases of implant failure in intravenous bisphosphonate cases were identified. On the basis of the assumption that 5% of the patients were taking an oral bisphosphonate, 1 in 114 (0.89%) had implant failure. CONCLUSION: In patients taking oral bisphosphonates...

Comparison of an analytical expression of resin composite curing stresses with in vitro observations of marginal cracking

Kahler, W.; Swain, M.; Kotooussov, A.
Fonte: Mosher & Linder Inc Publicador: Mosher & Linder Inc
Tipo: Artigo de Revista Científica
Publicado em //2010 EN
Relevância na Pesquisa
49.13457%
PURPOSE: To observe the marginal failure at the enamel-resin composite interface upon curing, and utilize a recently developed analytical model for curing stresses to relate to the extent of interfacial failure. METHODS: Occlusal cavity preparations were restored with Heliomolar, Filtek Z100 or UltraSeal XT Plus resin composites. Teeth were restored with either bulk or incremental placement. The control group was not restored. Teeth were placed in an acrylic ring and embedded in cold mounting epoxy resin and the crown sectioned so that the tooth/restoration interface and cavosurface margin could be visualized with an optical microscope. A recently developed simplified analytical approach was utilized to evaluate the composite-enamel interface tensile stresses for these materials theoretically and thereby the fracture susceptibility of the resin-enamel interface during polymerization. RESULTS: White lines, enamel cracks and interfacial failure of the bond were evident for all three materials evaluated (P < 0.01). Gaps at the enamel-composite interface measured 1-10 microm and were more evident for Ultra Seal XT Plus and Z100 than Heliomolar. Conversely, cracking of the enamel adjacent to the interface was more evident for Heliomolar. Statistical analysis showed that enamel cracking and interfacial failure was significant for all groups (P < 0.01). An inverse relationship was noted between enamel cracking and interfacial failure (P < 0.05). The predictions for the extent of cracking from the mathematical modeling match the experimental data and prior studies.; http://www.ncbi.nlm.nih.gov/pubmed/21344837; B. Kahler...

Do socioeconomic determinants affect the quality of posterior dental restorations? A multilevel approach

Correa, M.; De Anselmo Peres, M.; Glazer De Anselmo Peres, K.; Horta, B.; Barros, A.; Demarco, F.
Fonte: Elsevier Sci Ltd Publicador: Elsevier Sci Ltd
Tipo: Artigo de Revista Científica
Publicado em //2013 EN
Relevância na Pesquisa
48.635005%
OBJECTIVES: This study aimed to evaluate posterior restorations placed in young adults, investigating the association between social determinants experienced during the life course and the quality of tooth fillings. METHODS: A representative sample (n=720) of all 5914 individuals who were born in Pelotas in 1982 was prospectively investigated, and posterior restorations were assessed at 24 years of age. Exploratory variables included demographic and socioeconomic, oral health and dental service payment mode during the life course. Tooth-related variables (type of tooth, material and size of cavity) were also analysed. RESULTS: Multilevel logistic regression models showed that individuals who were always poor from birth to age 23 [odds ratio (OR) 2.35 (1.38-4.00)] and whose mothers had less years of education at their birth (OR 2.60 (1.44-4.68)) were with unsatisfactory restorations in posterior teeth more often. In addition, caries presence at age 15 (high decayed, missing, filled teeth (DMFT) tertile) (OR 1.95 (1.25-3.03)) and cavities with four or more surfaces (OR 18.67 (9.25-37.68)) were associated with the outcome. CONCLUSIONS: These results show that socioeconomic characteristics of the individuals play an important role in restoration failures...

Optimum post and tooth root diameters for a cast post-core system

Mou, Y.; Chen, Y.M.; Smales, R.; Yip, K.
Fonte: Mosher & Linder Inc Publicador: Mosher & Linder Inc
Tipo: Artigo de Revista Científica
Publicado em //2009 EN
Relevância na Pesquisa
48.365933%
PURPOSE: To investigate the optimum diameter for the tapered post of a cast alloy post-core system relative to the root diameter, when measured at the root face, that is required to minimize both post and root failures. METHODS: 32 extracted maxillary central incisor teeth were each decoronated perpendicular to the long axis at a point 2.0 mm occlusal to the labial cemento-enamel junction. Following endodontic canal obturation, the teeth were assigned randomly to four equal groups for different diameter tapered post space preparations. Then 1.10, 1.50, 1.70, and 2.00 mm diameter cast Ni-Cr alloy post-cores and complete crowns without ferrules were fabricated. Each root was embedded in a large gypsum stone block and the crown loaded palatally at 135 degrees from the long axis in a universal testing machine at a crosshead speed of 1.0 mm/minute until failure. Results were analyzed using one-way ANOVA with Tukey-Kramer post hoc tests, and Fisher's exact test, with alpha = 0.05 for statistical significance. RESULTS: Mean failure resistance loads were: 0.60, 0.91, 1.00, and 1.38 kN (P < 0.001). All of the 1.10 mm posts failed, without any root fractures. Conversely, none of the 2.00 mm posts failed, but all of the roots fractured. The optimum post to root diameter ratio to minimize failures was approximately 1:4.; http://www.researchgate.net/publication/41940997; Yong-Bin Mou...

Effect of material properties of composite restoration on the strength of the restoration-dentine interface due to polymerization shrinkage, thermal and occlusal loading

Borkowski, K.; Kotooussov, A.; Kahler, W.
Fonte: Elsevier Sci Ltd Publicador: Elsevier Sci Ltd
Tipo: Artigo de Revista Científica
Publicado em //2007 EN
Relevância na Pesquisa
58.56393%
The purpose of this investigation was to adopt an analytical approach to analyse stresses at the restoration-dentine interface caused by polymerization shrinkage, occlusal and thermal loading with the primary focus on evaluating the effect of the material properties of the composite restoration on the strength of the interface. Some essential simplifications were employed to derive an explicit analytical solution. The results confirm previous findings that interfacial stresses due to polymerization shrinkage are increased with the higher modulus of elasticity of the restoration, while Poisson's ratio of the restorative material has a very small influence on these stresses. Occlusal loading resulted in much lower interfacial stresses when compared to shrinkage and thermal loads. The obtained results were in a good agreement with other numerical and clinical studies. From the modelling analysis it was found that the majority of commercially available composite restorative materials are expected to create significant interfacial stresses when subjected to cold temperatures. In addition, it was shown that there is a considerable potential for interfacial stresses to be minimised by an appropriate selection of thermo-mechanical properties of the restorative material especially with the new finding on the negative temperature variation effect.; http://www.elsevier.com/wps/find/journaldescription.cws_home/30456/description#description; Krzysztof Borkowski...

Managing dental caries with atraumatic restorative treatment in children: successful experience in three Latin American countries

Estupiñán-Day,Saskia; Tellez,Marisol; Kaur,Sundeep; Milner,Trevor; Solari,Alfredo
Fonte: Organización Panamericana de la Salud Publicador: Organización Panamericana de la Salud
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2013 EN
Relevância na Pesquisa
48.494336%
OBJECTIVE: To compare survival rates and cost differentials between the atraumatic restorative treatment (ART) technique and amalgams by type of dental personnel in Ecuador, Panama, and Uruguay. METHODS: Children 7 to 9 years of age in rural and urban schools with at least one lesion with initial cavitated enamel caries or a dentinal lesion on a first permanent molar were selected and randomized into the ART (intervention) or amalgam (control) group. Restoration failure was evaluated at 12 and 24 months. Cooperation and pain experienced during the procedures were measured. Cumulative and incident failure of restorations at 12 and 24 months was calculated for dentists who placed ART or amalgam restorations and auxiliaries who placed ART restorations at 12 months only. RESULTS: The total sample comprised 1 629 children. Study groups were similar by country, gender, and geographic location. Cumulative failure rate at 12 months varied by group: dentists' amalgam, 0.9% to 5.7%; dentists' ART, 2.0% to 10.5%; and auxiliaries' ART, 5.7% to 15.8%. At 24 months, higher cumulative failures were observed for the dentists' amalgam group compared with the dentists' ART group in Ecuador and Panama but not in Uruguay. Amalgam was least likely to have the best level of cooperation and an auxiliary using ART was associated with the least pain. The cost of using the ART approach for dental caries treatment...