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1.
Community Dent Oral Epidemiol ; 41(6): 499-508, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23398352

RESUMO

OBJECTIVES: To investigate the appropriateness of different measures of socio-economic inequalities, in relation to adult oral health in Scotland, utilizing data from a series of large, representative population surveys. METHODS: The Scottish Health Surveys (SHeS) (1995; 1998; 2003; 2008/09) are cross-sectional national population-based surveys used to monitor health status in those living in private households. The age groups included in this study are as follows: 45-54; 55-64 years: all survey years; 65-74: 1998 onwards; 75+: 2003 onwards. Primary outcome was no natural teeth (edentulism). Three measures of socio-economic position: Occupational social class, Education, Carstairs deprivation score (2001) were used. Simple (absolute/relative differences) and complex measures (Slope Index, Relative Index, Concentration Index and c-index) of inequality were produced for each age group across all four surveys. RESULTS: Simple and complex (absolute) measures of inequality have both demonstrated narrowing disparities in edentulism over time in the 45- to 64-year-old group, a levelling off in those aged 65 and above, and a rise in those aged 75+. Complex relative measures (RII, Concentration Index and c-index), however, show an increasing trend in inequalities over time for all age groups, suggesting that rates of improvement in edentulism rates are not uniform across all social groups. CONCLUSIONS: Simple absolute inequality provides a quick and easy indication of the extent of disparities between extreme groups, whereas complex measures (absolute and relative) consider the gradient in health across all social groups. We have demonstrated that both are useful measures of inequality and should be considered complementary to one another. The appropriate choice of complex measure of inequality will depend on the audience to whom the results are to be communicated. This methodological approach is not confined to oral health but is applicable to other health outcomes that are socially patterned.


Assuntos
Disparidades nos Níveis de Saúde , Saúde Bucal/estatística & dados numéricos , Adolescente , Adulto , Fatores Etários , Idoso , Estudos Transversais , Escolaridade , Feminino , Inquéritos Epidemiológicos , Humanos , Masculino , Pessoa de Meia-Idade , Boca Edêntula/epidemiologia , Escócia/epidemiologia , Fatores Socioeconômicos , Adulto Jovem
2.
J Dent ; 40(11): 906-12, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22819811

RESUMO

OBJECTIVES: This study evaluated the effect of different surface conditioning methods on the tensile bond strength (TBS) and integrity of the leucite-reinforced glass ceramic (Cerana(®) inserts)-resin composite interface, using four commercially available ceramic repair systems. METHODS: Two hundred extra-large Cerana(®) inserts were mechanically treated and stored in artificial saliva for 3 weeks and subsequently randomly assigned to one of the following ceramic repair systems (n=40/group): Group 1, Ceramic Repair(®) (Ivoclar Vivadent, Liechtenstein); Group 2, Cimara(®) (Voco, Germany); Group 3, Clearfil Repair(®) (Kuraray, Japan); Group 4, CoJet system(®) (3M ESPE, Germany); and Group 5, no surface conditioning and no adhesive system applied: the control group. Subsequently, resin composite material was added to the substrate surfaces and the ceramic-resin composite specimens were subjected to TBS testing. Representative samples from the test groups were subjected to scanning electron microscopy (SEM) to determine the mode of failure. The data were analysed statistically using a one-way multivariate analysis of variance and Kruskal-Wallis test at a 95% confidence interval level. RESULTS: Surface conditioning with the CoJet(®) system resulted in significantly higher bond strength values (5.2 ± 1.1 MPa) than surface conditioning with the other repair systems (p=0.03). The SEM examination of the failed interfaces revealed that all the specimens examined failed adhesively. SIGNIFICANCE: Whilst highest bond strength values were observed with the CoJet(®) system all tested repair systems resulted in relatively weak TBS values and, as a consequence, these repair systems may be indicated only as interim measures.


Assuntos
Cerâmica , Porcelana Dentária , Reparação em Prótese Dentária/métodos , Cimentos de Resina , Resinas Compostas , Colagem Dentária , Análise do Estresse Dentário , Teste de Materiais , Distribuição Aleatória , Resistência à Tração
3.
J Prosthodont ; 21(7): 516-22, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22672417

RESUMO

PURPOSE: Candida albicans is the predominant oral yeast associated with denture-induced stomatitis, and with an increasing population of denture wearers its incidence is increasing. Maintaining good oral and denture hygiene, through chemical and/or mechanical intervention, is essential to reducing this disease. The aim of this study, using a robust adherent C. albicans cell model system, was to evaluate and compare the efficacy of a novel denture cleanser to the efficacy of a commonly used dentifrice coupled with brushing. MATERIALS AND METHODS: Four C. albicans strains isolated from individuals diagnosed as having denture-induced stomatitis, were adhered to denture acrylic resin sections (1 cm(2) by 1 mm thickness) and after 4 hours of growth, challenged daily sequentially for 4 days with a denture cleanser (Polident) or intermittently with denture cleanser (day 1), then dentifrice (Colgate Cavity Protection Toothpaste) and brushing (days 2 and 3) and denture cleanser (day 4). Colony forming units were evaluated for each treatment, as were the levels of regrowth. Scanning electron microscopy (SEM) was also performed. Microbial susceptibility testing and time-kill studies were performed on biofilms. A coculture model was also used to assess interleukin-8 (IL-8) production from treated biofilms. RESULTS: It was shown that sequential treatment with the denture cleanser killed and inhibited regrowth each day. Intermittent treatment showed that viable C. albicans biofilms were only retained rather than being dispersed, which could be visualized by SEM. Time-kill studies demonstrated that the novel denture cleanser was highly active and killed quickly, unlike the dentifrice. IL-8 was expressed in greater levels in 24-hour biofilms than in 4-hour biofilms, but treatment with denture cleanser reduced IL-8 output. CONCLUSIONS: The data indicate that maintaining good oral health for denture wearers requires daily use of a denture cleanser rather than an alternating regimen. The inability of the denture cleanser to sterilize during intermittent treatments demonstrates the difficulty in controlling established biofilm. Moreover, the presence of mature biofilm may result in high levels of inflammation, but this can be controlled through denture cleansing.


Assuntos
Candida albicans/efeitos dos fármacos , Candidíase Bucal/prevenção & controle , Bases de Dentadura/microbiologia , Higienizadores de Dentadura/farmacologia , Estomatite sob Prótese/prevenção & controle , Resinas Acrílicas , Biofilmes/efeitos dos fármacos , Técnicas de Cocultura , Dentifrícios/farmacologia , Humanos , Interleucina-8/biossíntese , Higiene Bucal/métodos , Estomatite sob Prótese/microbiologia , Escovação Dentária
4.
J Dent ; 40(1): 15-21, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22100436

RESUMO

OBJECTIVES: This study evaluated the effect of different surface conditioning methods on the tensile bond strength (TBS) and integrity of the amalgam-resin composite interface, using commercially available restoration repair systems. METHODS: One hundred and sixty Gamma 2 amalgam specimens were stored in artificial saliva for 2 weeks and then randomly assigned to one of the following conditioning groups (n=20/group): Group 1: air abrasion, alloy primer and 'Panavia 21', Group 2: air abrasion and 'Amalgambond Plus', Group 3: air abrasion and 'All-Bond 3', Group 4: diamond bur, alloy primer and 'Panavia 21', Group 5: diamond bur and 'Amalgambond Plus', Group 6: diamond bur and 'All-Bond 3', Group 7: silica coating technique, and Group 8: non-conditioned amalgam surfaces (control group). Subsequently, resin composite material was added to the substrate surfaces and the amalgam-resin composite specimens were subjected to TBS testing. Representative samples from the test groups were subjected to scanning electron microscopy and surface profilometry. The data was analysed statistically with one-way ANOVA and post hoc Tukey's tests (α=0.05). RESULTS: The mean TBS of amalgam-resin composite ranged between 1.34 and 5.13MPa and varied with the degree of amalgam surface roughness and the type of conditioning technique employed. Significantly highest TBS values (5.13±0.96MPa) were obtained in Group 1 (p=0.013). CONCLUSION: Under the tested conditions, significantly greater tensile bond strength of resin composite to amalgam was achieved when the substrate surface was conditioned by air abrasion followed by the application of the Panavia 21 adhesive system. CLINICAL SIGNIFICANCE: Effecting a repair of an amalgam restoration with resin composite via the use of air abrasion and application of Panavia 21 would seem to enhance the integrity of the amalgam-resin composite interface. Clinical trials involving the implementation of this technique are indicated to determine the usefulness of this technique.


Assuntos
Resinas Compostas , Amálgama Dentário , Colagem Dentária , Corrosão Dentária/métodos , Reparação de Restauração Dentária/métodos , Análise do Estresse Dentário , Adesivos Dentinários , Metacrilatos , Fosfatos , Distribuição Aleatória , Cimentos de Resina , Dióxido de Silício , Propriedades de Superfície , Resistência à Tração
5.
Int J Prosthodont ; 24(6): 589-98, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22146260

RESUMO

PURPOSE: This study investigated how ribbed design features, including palatal rugae, may be used to significantly improve the structural performance of a maxillary denture under load. MATERIALS AND METHODS: A computer-aided design model of a generic maxillary denture, incorporating various rib features, was created and imported into a finite element analysis program. The denture and ribbed features were assigned the material properties of standard denture acrylic resin, and load was applied in two different ways: the first simulating a three-point flexural bend of the posterior section and the second simulating loading of the entire palatal region. To investigate the combined use of ribbing and reinforcement, the same simulations were repeated with the ribbed features having a Young modulus two orders of magnitude greater than denture acrylic resin. For a prescribed load, total displacements of tracking nodes were compared to those of a control denture (without ribbing) to assess relative denture rigidity. RESULTS: When subjected to flexural loading, an increase in rib depth was seen to result in a reduction of both the transverse displacement of the last molar and vertical displacement at the centerline. However, ribbed features assigned the material properties of denture acrylic resin require a depth that may impose on speech and bolus propulsion before significant improvements are observed. CONCLUSION: The use of ribbed features, when made from a significantly stiffer material (eg, fiber-reinforced polymer) and designed to mimic palatal rugae, offer an acceptable method of providing significant improvements in rigidity to a maxillary denture under flexural load.


Assuntos
Resinas Acrílicas , Desenho Assistido por Computador , Planejamento de Dentadura , Prótese Total Superior , Análise do Estresse Dentário/métodos , Módulo de Elasticidade , Análise de Elementos Finitos , Palato Duro/anatomia & histologia , Maleabilidade , Propriedades de Superfície
6.
Dent Update ; 38(3): 150-2, 154-6, 158, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21667828

RESUMO

UNLABELLED: With the increasing use of ceramics in restorative dentistry, and trends to extend restoration longevity through the use of minimal interventive techniques, dental practitioners should be familiar with the factors that may influence the decision either to repair or replace fractured metal-ceramic and all-ceramic restorations and, also, the materials and techniques available to repair these restorations. This second of two papers addresses the possible modes of failure of ceramic restorations and outlines indications and techniques in this developing aspect of restoration repair in clinical practice. CLINICAL RELEVANCE: The repair of metal-ceramic and all-ceramic restorations is a reliable low-cost, low-risk technique that may be of value for the management of loss or fracture of porcelain from a crown or bridge in clinical practice.


Assuntos
Colagem Dentária/métodos , Porcelana Dentária/química , Reparação em Prótese Dentária/métodos , Restauração Dentária Permanente , Ligas Metalo-Cerâmicas/química , Coroas , Falha de Restauração Dentária , Desgaste de Restauração Dentária , Facetas Dentárias , Prótese Adesiva , Humanos
7.
Dent Update ; 38(2): 78-80, 82-4, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21500616

RESUMO

UNLABELLED: The presentation of patients with failing dental restorations that exhibit minor defects is a common clinical situation in everyday dental practice. The repair of such restorations, rather than replacement, is increasingly considered to be a viable alternative to the replacement of the defective restoration. This first of two papers considers indications and techniques for the repair of defective direct composite restorations. It is possible that some dental practitioners are unaware of the option of repair rather than replacement of composite restorations. This article provides an overview of contemporary knowledge and understanding of restoration repair in the clinical management of defective composite restorations. CLINICAL RELEVANCE: A sound understanding of the indications, benefits and techniques of direct composite restoration repair could allow the longevity of the existing restoration to be extended without unnecessarily sacrificing healthy tooth structure.


Assuntos
Resinas Compostas/química , Materiais Dentários/química , Reparação em Prótese Dentária , Falha de Restauração Dentária , Restauração Dentária Permanente/classificação , Cor , Contraindicações , Tomada de Decisões , Cárie Dentária/etiologia , Polimento Dentário/métodos , Desgaste de Restauração Dentária , Humanos , Planejamento de Assistência ao Paciente , Seleção de Pacientes , Recidiva , Retratamento , Propriedades de Superfície , Fraturas dos Dentes/terapia
8.
Biomed Mater Eng ; 20(5): 243-9, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21084736

RESUMO

Dental impression materials are used to create an inverse replica of the dental hard and soft tissues, and are used in processes such as the fabrication of crowns and bridges. The accuracy and dimensional stability of impression materials are of paramount importance to the accuracy of fit of the resultant prosthesis. Conventional methods for assessing the dimensional stability of impression materials are two-dimensional (2D), and assess shrinkage or expansion between selected fixed points on the impression. In this study, dimensional changes in four impression materials were assessed using an established 2D and an experimental three-dimensional (3D) technique. The former involved measurement of the distance between reference points on the impression; the latter a contact scanning method for producing a computer map of the impression surface showing localised expansion, contraction and warpage. Dimensional changes were assessed as a function of storage times and moisture contamination comparable to that found in clinical situations. It was evident that dimensional changes observed using the 3D technique were not always apparent using the 2D technique, and that the former offers certain advantages in terms of assessing dimensional accuracy and predictability of impression methods. There are, however, drawbacks associated with 3D techniques such as the more time-consuming nature of the data acquisition and difficulty in statistically analysing the data.


Assuntos
Alginatos/química , Materiais para Moldagem Odontológica/química , Técnica de Moldagem Odontológica , Teste de Materiais , Elastômeros de Silicone/química , Imageamento Tridimensional , Modelos Dentários , Polivinil/química , Propriedades de Superfície , Fatores de Tempo
9.
Prim Dent Care ; 17(3): 143-6, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20594428

RESUMO

AIM: The aim of the study was to determine the prevalence of dental, orofacial and head injuries and of mouthguard use among schoolboy rugby players. MATERIALS AND METHODS: All members of the first and second XV rugby squads at three secondary schools (two in England and one in Australia) were included in the study. All participants answered a questionnaire that sought information regarding dental, orofacial and head injuries. Statistical differences between groups were determined using chi-square tests for categorical variables and Kruskal-Wallis tests for discrete (count) variables. RESULTS: One hundred and seventy-eight completed questionnaires were returned (100% response rate). One hundred and twenty-five (70%) players reported having sustained at least one injury (range 1-4). Facial injuries were common. Dental injuries were the most prevalent injury: 46 (26%) were reported. Fractured teeth were reported by 20 (11%) players, and avulsed teeth by 7 (4%). There was evidence of a difference between schools in the prevalence of injured players (P=0.014), but among those reporting injuries, there was no difference between schools in the number of injuries (P=0.95). All players said that they used a mouthguard regularly. CONCLUSIONS: Dental, orofacial and head injuries were commonly reported. Dental injuries were the most prevalent type of injury. All players used mouthguards regularly.


Assuntos
Traumatismos Craniocerebrais/epidemiologia , Futebol Americano/lesões , Traumatismos Dentários/epidemiologia , Traumatismos Faciais/epidemiologia , Humanos , Protetores Bucais/estatística & dados numéricos , Projetos Piloto , Prevalência , Instituições Acadêmicas , Inquéritos e Questionários , Reino Unido/epidemiologia
10.
Eur J Prosthodont Restor Dent ; 18(4): 189-94, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21265439

RESUMO

The purpose of this study was to evaluate the hardness and energy absorption properties of four commercially available chairside silicone denture soft lining materials and to compare their properties with those of a heat-polymerized silicone denture liner. The denture lining materials investigated were four auto-polymerising silicone soft liners (GC Reline Soft, Ufigel SC, Elite Soft Relining and Tokuyama Sofreliner S) and a heat-polymerised silicone liner (Molloplast B). The soft liners were processed according to manufacturers' instructions. The specimens for hardness testing were 38 x 38 x 3 mm. The specimens for energy absorption test were 10 x 10 x 3 mm. In each test ten samples of each material were tested. There was strong evidence that Tokuyama Sofreliner S and, to a lesser extent, Ufigel SC, were less stiff and more resilient than Molloplast B. There was also strong evidence that both GC Reline Soft and Elite Soft Relining were harder than Molloplast B, while Ufigel SC and Tokuyama Sofreliner S were softer In conclusion differences existed between hardness and energy absorption properties of the soft lining materials.


Assuntos
Reembasadores de Dentadura , Análise do Estresse Dentário , Elasticidade , Transferência de Energia , Dureza , Teste de Materiais , Silicones , Estatísticas não Paramétricas
11.
Prim Dent Care ; 16(4): 149-53, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19796516

RESUMO

AIM: To investigate the opinions of manufacturers of resin-based composite (RBC) towards the repair of their materials. METHODS: Representatives of 20 manufacturers of RBC were electronically mailed a questionnaire seeking information on aspects of the repair of direct composite restorations. RESULTS: The response rate was 100%. The findings indicated that although the majority of respondents regarded repair as a viable option for managing failing direct RBC restorations, marked variations were found to exist regarding recommendations for and contra-indications to performing repairs of RBC restorations. CONCLUSIONS: Within the limitations of the current study, the following conclusions can be drawn: (1) the majority of manufacturers of RBC materials are aware and in favour of repair as opposed to replacement of defective composite restorations; (2) there is a need for manufacturers to produce guidelines for repair of their materials; and (3) there is a need for robust randomised controlled dental practice-based clinical studies in the field of repair of composite restorations.


Assuntos
Resinas Compostas , Falha de Restauração Dentária , Restauração Dentária Permanente , Indústria Farmacêutica , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Inquéritos e Questionários
12.
Prim Dent Care ; 16(3): 99-102, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19566982

RESUMO

AIMS: The aims of this pilot study were to determine the prevalence of head, face and dental injuries sustained by schoolboys while playing cricket and to compare the prevalence of those injuries in England and Australia. METHODS: A questionnaire that determined distribution and prevalence of orofacial injuries sustained when playing cricket was distributed to all players (n=411) who played cricket in four private schools in England and four private schools in Australia. There was a 100% response rate. RESULTS: Fifty subjects (24.1%) from English schools and 52 subjects (25.5%) from Australian schools reported injury/injuries to the head, face and teeth. Australian cricketers reported more injuries per player. The distribution of injuries between the two countries was similar. Sixteen players had sustained loosened or broken teeth. Two players reported avulsed teeth. CONCLUSION: It was concluded that there was a high prevalence of head and orofacial injuries among the schoolboy cricketers but relatively few dental injuries. The distribution of types of head, face and dental injury in England and Australia were similar.


Assuntos
Traumatismos em Atletas/epidemiologia , Traumatismos Craniocerebrais/epidemiologia , Traumatismos Faciais/epidemiologia , Traumatismos Dentários/epidemiologia , Adolescente , Austrália/epidemiologia , Contusões/epidemiologia , Inglaterra/epidemiologia , Humanos , Lacerações/epidemiologia , Lábio/lesões , Masculino , Boca/lesões , Projetos Piloto , Prevalência , Avulsão Dentária/epidemiologia , Fraturas dos Dentes/epidemiologia
13.
Prim Dent Care ; 16(2): 75-8, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19366523

RESUMO

AIM: To assess the prevalence of orofacial complications associated with SCUBA (self-contained underwater breathing apparatus) diving. Main outcome measures were prevalence of orofacial pain and odontocrexis. METHOD: Two hundred divers at four dive centres on the north-east coast of Australia were asked to complete a questionnaire that requested information regarding diving experience and facial pain and dental symptoms experienced during diving. RESULTS: One hundred and twenty-five completed questionnaires were returned (63% response rate). The prevalence of reported orofacial pain was 44%. Twenty-one per cent reported toothache, 27% sinus pain, 16% jaw pain, and 12% other pain. The prevalence of odontocrexis was less than 1%. Less than 1% had lost a filling when diving. No divers reported a crown or bridge being dislodged during diving. CONCLUSION: Among those who returned questionnaires, orofacial pain in divers was common and odontocrexis was rare.


Assuntos
Mergulho/efeitos adversos , Dor Facial/etiologia , Fraturas dos Dentes/etiologia , Adulto , Austrália/epidemiologia , Barotrauma/epidemiologia , Barotrauma/etiologia , Falha de Restauração Dentária , Dor Facial/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Inquéritos e Questionários , Transtornos da Articulação Temporomandibular/etiologia , Fraturas dos Dentes/epidemiologia , Adulto Jovem
14.
J Biomed Mater Res A ; 90(4): 993-8, 2009 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-18655136

RESUMO

The majority of dental implants are composed primarily of titanium and have an outer layer of titanium dioxide. Crystalline titanium dioxide most commonly exists in one of the two structures, anatase and rutile, and both of these have been observed on commercially available dental implants. Early implant failure can be associated with postoperative infection due to implant contamination during or immediately after surgery. The impetus of this study was to investigate whether functionalization of anatase and rutile titanium dioxide surfaces with chlorhexidine-reduced subsequent colonization of the surface by Streptococcus gordonii. Exposure to 100 mg x L(-1) chlorhexidine for 60 s resulted in a fivefold reduction in S. gordonii coverage on anatase and a twofold reduction on rutile. This may be related to a preferential adsorption of chlorhexidine to anatase compared with rutile. The reduction in bacterial coverage was not due to desorption of chlorhexidine into solution. More bacteria were observed on anatase than rutile surfaces without chlorhexidine functionalization, indicating that crystal structure may have a significant effect on bacterial colonization. In conclusion, functionalization with chlorhexidine reduced bacterial coverage on titanium dioxide surfaces, and anatase surfaces may be more amenable to such treatment than rutile.


Assuntos
Aderência Bacteriana/efeitos dos fármacos , Clorexidina/farmacologia , Streptococcus gordonii/fisiologia , Titânio , Adsorção , Infecções Bacterianas/prevenção & controle , Clorexidina/química , Materiais Revestidos Biocompatíveis/química , Implantes Dentários/microbiologia , Streptococcus gordonii/efeitos dos fármacos , Propriedades de Superfície
15.
Prim Dent Care ; 15(2): 53-8, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18397592

RESUMO

AIM: To investigate the effect of water temperature, in association with four denture cleansers, on the colour and surface roughness of five soft lining materials. METHOD: Two silicone soft lining materials (Molloplast B and Sofreliner) represented the heat-cured, laboratory-based and chairside materials that are available. The wide range of chairside, acrylic resin-based, temporary soft lining materials was represented by Coe-Soft, Viscogel and Eversoft. An alkaline hypochlorite (Dentural) and three effervescent peroxide solutions with a range of active pH values (Steradent Active Plus, pH 6; Steradent Extra Strength, pH 3; Superdrug Fresh, pH 11) were selected as the cleansers. The denture cleansers were used at two temperatures: 55 degrees C (manufacturers' recommended temperature) and 80 degrees C. The colour of the specimens was evaluated using a colorimeter and the surface roughness was assessed using a three-dimensional, non-contact surface profilometer. This study reported on the effect of using both the higher temperatures and the recommended temperature on the colour and roughness of permanent and temporary soft lining materials. RESULTS AND CONCLUSION: The results of the study showed that the temperature of the water used with denture cleansers might have a detrimental effect on the colour and surface roughness of some permanent and temporary soft lining materials.


Assuntos
Materiais Biocompatíveis/química , Materiais Dentários/química , Higienizadores de Dentadura/química , Reembasadores de Dentadura , Água/química , Boratos/química , Cor , Colorimetria , Dimetilpolisiloxanos/química , Desinfetantes/química , Temperatura Alta , Humanos , Concentração de Íons de Hidrogênio , Ácido Hipocloroso/química , Imageamento Tridimensional , Teste de Materiais , Metacrilatos/química , Metilmetacrilatos/química , Oxidantes/química , Peróxidos/química , Fosfatos/química , Elastômeros de Silicone/química , Cloreto de Sódio/química , Propriedades de Superfície , Temperatura
16.
Clin Implant Dent Relat Res ; 9(3): 121-7, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17716255

RESUMO

PURPOSE: The aim of this study was to investigate the effect of offsetting the middle or peripheral implant on the compressive stress values in the crestal bone around the neck of the dental implant. MATERIALS AND METHODS: Three finite element models describing three titanium implants installed in quadrilateral pieces of bone was executed. A 2-mm nickel chromium superstructure representing a bridge was modeled over the implant abutments. In model 1, implants were installed along a straight line. Model 2 had the middle implant installed outside the line connecting the two peripheral implants buccally. Model 3 had the mesial implant installed out of alignment. Six 100-N loads were modeled on top of the mesial and middle implants of the three models individually. Loads 1 and 2 were directed vertically on the mesial and middle implants, while loads 3 and 4 represented the horizontal loads in the buccal direction. Loads 5 and 6 were directed mesially on the mesial and central implants. Maximal compressive stress levels in the crestal bone of the three models were then investigated. RESULTS: The results demonstrated that offset implant installation revealed slightly lower bone stresses under buccally or lingually directed horizontal forces. Slightly higher bone stresses under vertical loads were observed. Horizontal mesial or distal loads resulted in slightly higher bone stresses than those caused by buccal or lingual loading. CONCLUSIONS: The in-line implant alignment clearly had the safest compressive stress outcome on the surrounding structure under vertical loads. Under buccolingual loads, implant alignment with peripheral offset would have, relatively, the safest compressive stress outcome on bone.


Assuntos
Implantação Dentária Endóssea/métodos , Implantes Dentários , Mandíbula/fisiologia , Fenômenos Biomecânicos , Ligas de Cromo/química , Simulação por Computador , Dente Suporte , Materiais Dentários/química , Prótese Dentária Fixada por Implante , Análise de Elementos Finitos , Humanos , Modelos Biológicos , Osseointegração/fisiologia , Estresse Mecânico , Propriedades de Superfície , Titânio/química , Suporte de Carga
17.
J Mater Sci Mater Med ; 18(7): 1439-47, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17387587

RESUMO

Bacterial colonisation of exposed implant and abutment surfaces can lead to peri-implantitis, a common cause of oral implant failure. When an abutment becomes exposed in the oral environment the typical recommendation is to debride it, to obtain a smoother surface which might be expected to reduce bacterial colonisation. The aim of this study was to evaluate, in vitro, a conventional polishing protocol (PP1) and a simplified polishing protocol (PP2), suggested to have advantages over PP1. The surface morphology and roughness of titanium abutments were characterised at each stage of polishing, and adhesion of oral bacteria was evaluated, using atomic force microscopy, environmental scanning electron microscopy and optical profilometry. PP1 and PP2 methodologies resulted in indistinguishable surface finishes, with fewer scratches than the unmodified surface, and equal roughness values. PP2 resulted in less disruption and less removal of surface material. Early biofilm formation by Streptococcus mutans was reduced on surfaces polished using PP2, but not PP1. Biofilms of Actinomyces naeslundii were more extensive on polished abutment surfaces. Simplified protocol PP2 may be preferable to conventional protocol PP1, since less material is removed, and there is less chance of rough areas remaining. Polishing, however, does not necessarily reduce oral bacterial colonisation.


Assuntos
Actinomyces/crescimento & desenvolvimento , Materiais Biocompatíveis/química , Biofilmes/crescimento & desenvolvimento , Streptococcus mutans/crescimento & desenvolvimento , Titânio/química , Actinomyces/isolamento & purificação , Teste de Materiais , Streptococcus mutans/isolamento & purificação , Propriedades de Superfície
18.
Eur J Prosthodont Restor Dent ; 12(1): 15-20, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15058177

RESUMO

There has been some disquiet over the use of mercury containing restorative materials. The most commonly used alternative is composite resin but this has the potential disadvantage associated with wear and marginal leakage, which in turn, has proven to result in secondary caries and sensitivity. To overcome the shortcomings of a directly placed composite restoration, the glass-ionomer/composite open sandwich technique was introduced followed by the subsequent introduction of compomer systems. The aims of this study were to evaluate the wear and clinical performance of a control group of amalgam restorations compared with that of a group of posterior composite resin restorations fillings and a group of compomer/composite open sandwich restorations placed by a single general dental practitioner. The duration of the study was 2 years. One hundred and thirty three (71.4%) patients were successfully recalled and the wear and clinical performance of each restoration after 6, 12 and 24 months was measured, indirectly. There was no statistically significant difference recorded between the groups at 6 months or 1 year (p > 0.05). However, at the end of the 2-year study, there was a significantly lower rate of wear recorded for the control amalgam restorations compared with other two groups (p = 0.033). There was no statistically significant difference in wear recorded between the two groups of tooth-coloured restorations (p > 0.05). With regards to clinical performance of the restorations, occlusal and proximal contacts in each group of restoration remained satisfactory throughout the study.


Assuntos
Desgaste de Restauração Dentária , Restauração Dentária Permanente/métodos , Acetona , Adolescente , Adulto , Compômeros , Resinas Compostas , Amálgama Dentário , Adesivos Dentinários , Humanos , Ácidos Polimetacrílicos , Estudos Prospectivos , Cimentos de Resina , Estatísticas não Paramétricas
19.
Int J Prosthodont ; 15(6): 549-52, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12475160

RESUMO

PURPOSE: In this study, seven denture cleansers were evaluated for their mode of action of tea stain removal from Perspex acrylic resin material. MATERIALS AND METHODS: Perspex acrylic resin specimens were stained using a combination of chlorhexidine and tea solution. The specimens were also treated with saliva to form an initial pellicle layer and facilitate the uptake of the stain. The capacity for stain removal was determined by measuring the optical density of the treated specimens by using a spectrophotometer. These were then exposed, for 5 minutes, to seven denture cleansers to demonstrate the percentage stain-removal ability of each cleanser. The same procedure was applied for roughened Perspex acrylic resin specimens. Water was used as a control in the two parts of the experiment. RESULTS: The products containing alkaline hypochlorite had the highest ability for removing stain from the acrylic resin material together with a bleaching effect. The results varied when the same denture cleansers were used on the roughened Perspex surface, and this was attributed to the presence of irregularities and porosities on the blocks. CONCLUSION: Denture cleansing agents containing hypochlorite and Boots Denture Cleaning Powder (constituents not stated by the manufacturer) exhibited the ability to remove stain from the denture base materials most effectively. Irregularities and porosities present on the denture surface played a major role in reducing the activity of denture cleaning agents and hence increased stain and plaque retention.


Assuntos
Resinas Acrílicas/química , Higienizadores de Dentadura/química , Dentaduras , Polimetil Metacrilato/química , Chá/química , Anti-Infecciosos Locais/química , Clorexidina/química , Cor , Película Dentária , Humanos , Ácido Hipocloroso/química , Óptica e Fotônica , Oxidantes/química , Porosidade , Saliva/química , Espectrofotometria , Espectrofotometria Ultravioleta , Propriedades de Superfície , Fatores de Tempo
20.
Int J Prosthodont ; 15(1): 55-8, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-11887600

RESUMO

PURPOSE: The purpose of the present study was to investigate the effect of roughening the denture base surface on the tensile and shear bond strengths of a poly(dimethylsiloxane) resilient lining material (Molloplast-B) bonded to a heat-cured acrylic resin denture base material. These measured bond strengths were compared to those obtained by packing the soft lining material against poly(methyl methacrylate) (PMMA) denture base acrylic resin dough. MATERIALS AND METHODS: Three groups of 10 specimens each were constructed for both tensile and shear tests. In the first group, Molloplast-B was packed against cured PMMA denture base surface. In the second group, Molloplast-B was packed against cured PMMA denture base whose surface had been roughened with an acrylic bur. In a third group, Molloplast-B was packed against PMMA denture base acrylic resin dough. RESULTS: Molloplast-B exhibited significantly higher tensile and shear bond strengths when packed against acrylic resin dough. Roughening the denture base surface prior to the application of Molloplast-B had a statistically significant weakening effect on tensile bond strength compared with the smooth surface and the acrylic resin dough. For the shear bond strength, roughening the surface produced a nonsignificant increase compared with the smooth surface, but the bond was weaker than when packed against acrylic resin dough. CONCLUSION: Significant differences in tensile and shear bond strength were recorded between the three methods used to bond Molloplast-B to denture base material.


Assuntos
Colagem Dentária , Bases de Dentadura , Reembasadores de Dentadura , Polimetil Metacrilato , Análise de Variância , Materiais Biocompatíveis , Dimetilpolisiloxanos , Teste de Materiais , Elastômeros de Silicone , Estresse Mecânico , Propriedades de Superfície , Resistência à Tração
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