RESUMO
PURPOSE: To evaluate the effect of different cavity designs and cement types on the fracture resistance of monolithic zirconia inlay-retained fixed dental prostheses (IRFDPs). MATERIALS AND METHODS: Four study models consisting of a second premolar, a missing first molar, and a second molar were used for the different cavity designs. Four different inlay cavity designs were prepared: DO-MO (disto-occlusal-mesio-occlusal cavity), MOD-MOD (mesio-occlusodistal-mesio-occlusodistal cavity), WDO-WMO (DO-MO with additional wings), and WMOD-WMOD (MOD-MOD with additional wings). A total of 64 epoxy resin models were produced and scanned individually. IRFDPs were then fabricated from monolithic zirconia using CAD/ CAM software. The bonding surface of the IRFDPs was airborne particle abraded (50-µm alumina/2 MPa), then cemented onto the epoxy resin models using two cementation protocols (n = 8 per group): (1) P = cemented with Panavia SA Cement Plus Automix; and (2) Z/C = cemented with MDP-containing primer (Z-Prime Plus) combined with Calibra Universal resin cement. All IRFDPs were fatigued through thermal aging (6,000 cycles/5°C to 55°C) and chewing simulations (600,000 cycles × 50-N load, 2.1 Hz). All IRFDPs were then subjected to a fracture resistance test using a universal testing machine with a crosshead speed of 0.2 mm/minute. Data were statistically analyzed using one- and two-way ANOVA and Bonferroni multiple comparisons test (P = .001). RESULTS: The mean fracture load (N) of the designs were as follows: WMODWMOD = 1,111.1; WDO-WMO = 1,057.4; MOD-MOD = 725.6; DO-MO = 682.7. According to two-way ANOVA, the differences among the cavity designs were statistically significant (P < .05). CONCLUSION: The cavity design of IRFDPs affected the fracture resistance. However, the fracture resistance of monolithic zirconia IRFDPs with any cavity design was enough to withstand expected posterior chewing forces.
Assuntos
Restaurações Intracoronárias , Cimentos de Resina , Óxido de Alumínio , Cimentos Dentários , Materiais Dentários , Resinas Epóxi , ZircônioRESUMO
OBJECTIVE: The ancient Maya used to practice dental inlays as part of the cultural traditions. Most of those inlays remain in place after more than one thousand years. The purpose of this paper is to investigate the incidence of pulp pathosis associated with ancient Maya dental inlays to assess the impact that such common practice had on the population's oral health. DESIGN: We scored 193 anterior inlaid teeth from 107 pre-Hispanic Maya dentitions studied at three archaeological storage facilities (Universidad Autonoma de Yucatan, Harvard University, Atlas of Guatemala Project). Two hundred eleven untreated frontal teeth of pre-Hispanic Mayan collections were used as controls. We performed macroscopic, radiographic and microscopic analyses to assess the frequency of caries, pulp calcifications, internal root resorption (IRR), and periapical lesions (PALs). RESULTS: In the inlaid teeth, the frequencies of pulp calcifications, IRR, caries and PALs were 59.8%, 2.2%, 18.5% and 19.2%, respectively. Compared with untreated teeth, inlaid specimens exhibited greater susceptibility to caries, pulp calcifications, IRR and PALs than untreated teeth (pulp calcifications: 44.5%, IRR: 0%, caries: 1.4%, and PAL: 1.9%). Age-at-death did not have any significant influence on susceptibility to pulp calcifications, IRR, caries or PALs. CONCLUSIONS: We noted relatively low pulp irritation and a low frequency of carious infections, IRR and PALs in Mayan inlaid teeth. However, these levels exceeded the frequencies of untreated teeth from the same area and time period. We follow that the cements used by the pre-Hispanic Maya to fix the inlays into their sockets provided excellent sealing characteristics on average.
Assuntos
Polpa Dentária/patologia , Indígenas Centro-Americanos/história , Restaurações Intracoronárias/história , América Central , História Antiga , HumanosRESUMO
En la actualidad existen muchos materiales dentales para la restauraciónestética, sin embargo, su tiempo de vida clínico no se conoce ampliamente. Objetivo: Identificar las publicaciones recientes de los materiales de restauración libre de metal que incluyan estudios clínicos. Metodología: La búsqueda sistemática de la literatura se realizó en bases de datos de PubMed y SciELO; se consideraron publicacionesdel 2010-2015 y que fueran investigaciones clínicas exclusivamente.Las palabras clave utilizadas fueron: Veneer crowns, dental restorationsfree metal, metal free crowns, aesthetic crowns y restauraciones libres de metal, coronas de silicato de litio, tipos de cerámicas. Resultados: Se revisaron 40 artículos y 20 cumplieron con los criterios de selección para la revisión bibliográfica. Todas las restauraciones protésicas libres de metal muestran un desempeño clínico muy similar a los tres años. Las restauraciones de zirconia y disilicato de litio por CAD mostraronel mejor éxito clínico. Conclusión: El éxito clínico de las restauracioneslibres de metal de esta revisión de la literatura muestra que van de un92.7 al 100 por ciento a tres o más años de seguimiento...
Assuntos
Humanos , Cerâmica/classificação , Facetas Dentárias/estatística & dados numéricos , Estética Dentária , Restauração Dentária Permanente/estatística & dados numéricos , Zircônio/classificação , Compostos de Lítio/classificação , Desenho Assistido por Computador/métodos , Restaurações Intracoronárias , Materiais Biocompatíveis/classificação , Materiais Dentários/classificação , Óxido de Alumínio/classificação , Interpretação Estatística de Dados , Propriedades de SuperfícieRESUMO
PURPOSE: To evaluate the fracture strength and the failure mode of endodontically treated teeth restored with composite resin overlays with and without glass-fiber reinforcement. MATERIALS AND METHODS: A total of 32 extracted molars were divided into four equal groups. In the NFR-NFRC (no foundation restoration, no fiber-reinforced composite) and NFR-FRC (no foundation restoration, fiber-reinforced composite) groups, only a 5-mm-thick composite resin layer sealed the pulp chamber floors, whereas in the FR-NFRC (foundation restoration, no fiber-reinforced composite) and FR-FRC (foundation restoration, fiber-reinforced composite) groups, a 3.0-mm foundation restoration was used. NFR-NFRC and FR-NFRC groups were restored with composite resin overlays, whereas NFR-FRC and FR-FRC groups were restored with fiber-reinforced composite resin overlays. All specimens were subjected to mechanical loading in a computer-controlled masticator and then the fracture resistance was evaluated. Differences in means were compared using two-way ANOVA and Tukey's test. The level of significance was set at É = 0.05. RESULTS: All specimens successfully completed the fatigue test. The least fracture-resistant group was NFR-FRC, exceeded by FR-NFRC, NFR-NFRC, and FR-FRC, in that order, with FR-FRC being the most fracture-resistant group. Statistically significant differences were detected between the pairs NFR-NFRC/FR-FRC (p = 0.001), NFR-FRC/FR-FRC (p = 0.001), and FR-NFRC/FR-FRC (p = 0.001). Eight vertical root fractures occurred in group FR-NFRC, six in group NFR-NFRC, four in group NFR-FRC, and none occurred in group FR-FRC. CONCLUSIONS: Within the limitations of this in vitro study, the incorporation of glass fibers and the presence of a foundation restoration were found to increase the fracture resistance and can favorably influence the fracture mode.
Assuntos
Resinas Compostas/química , Materiais Dentários/química , Vidro/química , Restaurações Intracoronárias , Fraturas dos Dentes/fisiopatologia , Dente não Vital/terapia , Condicionamento Ácido do Dente/métodos , Idoso , Óxido de Alumínio/química , Fenômenos Biomecânicos , Força de Mordida , Corrosão Dentária/métodos , Cavidade Pulpar/ultraestrutura , Análise do Estresse Dentário/instrumentação , Humanos , Teste de Materiais , Metacrilatos/química , Pessoa de Meia-Idade , Poliuretanos/química , Distribuição Aleatória , Preparo de Canal Radicular/métodos , Silanos/química , Estresse Mecânico , Fatores de Tempo , Preparo do Dente/métodos , Raiz Dentária/lesões , Água/químicaRESUMO
STATEMENT OF PROBLEM: Additional polymerization of indirect composite resins enhances their physical properties but lessens the potential for chemical bonding. PURPOSE: The purpose of this in vitro study was to evaluate the influence of different surface treatments and 6-month water storage on the microtensile bond strength (µTBS) of composite resin onlays. MATERIAL AND METHODS: Composite resin onlays (Filtek Z250) randomly received 6 different surface treatments: (1) airborne-particle abrasion with 27-µm alumina particles+Adper Scotchbond 1XT adhesive application, (2) airborne-particle abrasion with alumina particles+silane application (ESPE SIL)+Adper Scotchbond 1XT, (3) airborne-particle abrasion with alumina particles+Scotchbond Universal adhesive, (4) tribochemical silica coating with 30-µm particles (CoJet Sand)+Adper Scotchbond 1XT adhesive, (5) tribochemical silica coating+silane application+Adper Scotchbond 1XT, and (6) tribochemical silica coating+Scotchbond Universal adhesive. Onlays were luted to fresh composite resin specimens with RelyX Ultimate resin cement. Bonded assemblies were stored in water for 24 hours or 6 months at 37°C and subjected to the µTBS test. Additional surface-treated composite resin onlays were analyzed with a contact profilometer to determine average roughness, and micromorphologic changes were analyzed with scanning electron microscopy. RESULTS: Airborne-particle abrasion with alumina followed by Adper Scotchbond 1XT or Scotchbond Universal adhesive application provided the highest bond strength values at 24 hours. Lower values were obtained after tribochemical silica coating. After 6 months of artificial aging, airborne-particle abrasion with alumina or silica-coated alumina particles followed by Scotchbond Universal application yielded the greatest bond strength results. Airborne-particle abrasion with alumina produced the highest roughness values and a more irregular surface. CONCLUSION: Adhesive selection seems to be relevant to the µTBS of luted composite resin onlays after 6 months of water aging, as specimens treated with Scotchbond Universal, after alumina airborne-particle abrasion or tribochemical silica coating, yielded the highest values and better aging stability.
Assuntos
Resinas Compostas/uso terapêutico , Colagem Dentária/métodos , Restaurações Intracoronárias/métodos , Abrasão Dental por Ar/métodos , Abrasão Dental por Ar/normas , Óxido de Alumínio/uso terapêutico , Colagem Dentária/normas , Análise do Estresse Dentário , Humanos , Técnicas In Vitro , Restaurações Intracoronárias/normas , Cimentos de Resina/uso terapêutico , Propriedades de Superfície , Fatores de TempoRESUMO
PURPOSE: To evaluate the microleakage of Cerec 3, IPS e.max Press, and Turkom-Cera inlays cemented with three self-adhesive resin cements. MATERIALS AND METHODS: Ninety standardized class III MOD cavities were prepared in intact human mandibular third molars. Ceramic inlays were fabricated according to the manufacturer's instructions and were cemented using three self-adhesive resin cements (RelyX Unicem, Smartcem 2, and SpeedCEM). The specimens were stored in distilled water at 37°C for 24 h and subjected to 1000 thermocycles in water between 5°C and 55°C with a dwell time of 30 s. Subsequently, the specimens were subjected to 100,000 cycles of mechanical loading of 50 N at 1.6 Hz in 37°C water. The specimens were immersed in 0.5% basic fuchsine for 24 h and were sectioned using a low-speed diamond blade. The percentage of dye leakage at the tooth/restoration interface was measured and compared by Kruskal-Wallis tests with Bonferonni correction and Mann-Whitney U-tests at a significance level of p<0.05. RESULTS: Microleakage at the RelyX Unicem interface was lower than that with Smartcem 2 and SpeedCEM resin cements (p<0.05). Microleakage of the Turkom-Cera system was higher than Cerec 3 and IPS e.max Press ceramic inlays (p<0.05). CONCLUSIONS: Regardless of the ceramic system and self-adhesive resin cement used, dentin margins were associated with higher microleakage than enamel margins.
Assuntos
Cimentação/métodos , Infiltração Dentária/classificação , Porcelana Dentária/química , Restaurações Intracoronárias , Cimentos de Resina/química , Condicionamento Ácido do Dente/métodos , Óxido de Alumínio/química , Silicatos de Alumínio/química , Cerâmica/química , Corantes , Esmalte Dentário/ultraestrutura , Dentina/ultraestrutura , Humanos , Teste de Materiais , Compostos de Potássio/química , Corantes de Rosanilina , Silanos/química , Estresse Mecânico , Propriedades de Superfície , Temperatura , Fatores de Tempo , Água/químicaRESUMO
The purpose of this in-vitro study was to evaluate the influence of the framework design on the durability of inlay-retained cantilever fixed dental prostheses (IR-FDPs), made from zirconia ceramic, after artificial ageing. Forty-eight caries-free human premolars were prepared as abutments for all-ceramic cantilevered IR-FDPs using six framework designs: occlusal-distal (OD) inlay, OD inlay with an oral retainer wing, OD inlay with two retainer wings, mesial-occlusal-distal (MOD) inlay, MOD inlay with an oral retainer ring, and veneer partial coping with a distal box (VB). Zirconia IR-FDPs were fabricated via computer-aided design/computer-aided manufacturing (CAD/CAM) technology. The bonding surfaces were air-abraded (50 µm alumina/0.1 MPa), and the frameworks were bonded with adhesive resin cement. Specimens were stored for 150 d in a 37°C water bath during which they were thermocycled between 5 and 55°C for 37,500 cycles; thereafter, they were exposed to 600,000 cycles of dynamic loading with a 5-kg load in a chewing simulator. All surviving specimens were loaded onto the pontic and tested until failure using a universal testing machine. The mean failure load of the groups ranged from 260.8 to 746.7 N. Statistical analysis showed that both MOD groups exhibited significantly higher failure loads compared with the other groups (i.e. the three OD groups and the VB group) and that there was no significant difference in the failure load among the OD groups and the VB group. In conclusion, zirconia IR-FDPs with a modified design exhibited promising failure modes.
Assuntos
Materiais Dentários/química , Planejamento de Dentadura , Encaixe de Precisão de Dentadura , Retenção de Dentadura/instrumentação , Prótese Parcial Fixa , Restaurações Intracoronárias , Zircônio/química , Óxido de Alumínio/química , Dente Pré-Molar , Força de Mordida , Desenho Assistido por Computador , Dente Suporte , Colagem Dentária , Corrosão Dentária/métodos , Análise do Estresse Dentário/instrumentação , Facetas Dentárias , Humanos , Teste de Materiais , Cimentos de Resina/química , Estresse Mecânico , Temperatura , Fatores de Tempo , Preparo Prostodôntico do Dente/métodos , Água/químicaRESUMO
STATEMENT OF PROBLEM: Data are needed to evaluate the effect of various conditioning methods on immediate and delayed dentin sealing. PURPOSE: The purpose of this study was to test bond strength and surface configuration of immediate and delayed dentin sealing surfaces after applying different surface conditioning methods. MATERIAL AND METHODS: A total of 96 premolars were allocated to the immediate and delayed groups. The groups differed in the timing of dentin sealing. The immediate-group specimens were sealed with a self-etching adhesive immediately after preparation. The delayed-group specimens were sealed before the final ceramic restoration bonding. Provisional restorations were cemented on immediate-group and delayed-group specimens for 1 week. Four conditioning methods were used: polishing with fluoride-free pumice paste, airborne-particle abrasion with silicoated aluminum oxide, glycin, or calcium carbonate. After 24-hour storage, the shear bond strength was tested. The fractured specimens were optically inspected with a stereomicroscope. An optical 3-dimensional surface analysis was performed for quantitative and qualitative evaluation. A 2-way ANOVA with post hoc Tukey honestly significant difference tests for significant effects was performed to investigate effects of the 2 factors, sealing and conditioning, and their interaction (α=.05). RESULTS: Two-way ANOVA found significant differences between the sealing and conditioning groups. The immediate group had significantly lower bond strengths than the delayed group. In all groups, surface polishing produced the highest bond strengths, and airborne-particle abrasion with calcium carbonate produced the lowest. Fracture analysis found more failures in the adhesive layers in the immediate groups and a prevalence of mixed failures in the delayed groups. The surface analysis found significant abrasion and roughness when airborne-particle abrasion with silicoated aluminum oxide was used for immediate and delayed dentin sealing surfaces. CONCLUSIONS: Polishing and airborne-particle abrasion with silicoated aluminum oxide or glycin are efficient methods in conditioning immediate and delayed dentin sealing surfaces. Airborne-particle abrasion with silicoated aluminum oxide leaves significant surface alterations on both types of surfaces.
Assuntos
Colagem Dentária , Corrosão Dentária/métodos , Dentina/ultraestrutura , Resinas Acrílicas/química , Óxido de Alumínio/química , Silicatos de Alumínio/química , Carbonato de Cálcio/química , Resinas Compostas/química , Cimentos Dentários/química , Materiais Dentários/química , Análise do Estresse Dentário/instrumentação , Glicina/química , Humanos , Imageamento Tridimensional/métodos , Restaurações Intracoronárias , Cura Luminosa de Adesivos Dentários/métodos , Teste de Materiais , Compostos de Potássio/química , Cimentos de Resina/química , Resistência ao Cisalhamento , Silanos/química , Silicatos/química , Estresse Mecânico , Propriedades de Superfície , Temperatura , Fatores de Tempo , Óxido de Zinco/químicaRESUMO
Fractures during clinical function have been reported as the major concern associated with all-ceramic dental restorations. The aim of this study was to analyze the fracture features of glass-ceramic and zirconia-based restorations fractured during clinical use. Twenty-seven crowns and onlays were supplied by dentists and dental technicians with information about type of cement and time in function, if available. Fourteen lithium disilicate glass-ceramic restorations and 13 zirconia-based restorations were retrieved and analyzed. Fractographic features were examined using optical microscopy to determine crack initiation and crack propagation of the restorations. The material comprised fractured restorations from one canine, 10 incisors, four premolars, and 11 molars. One crown was not categorized because of difficulty in orientation of the fragments. The results revealed that all core and veneer fractures initiated in the cervical margin and usually from the approximal area close to the most coronally placed curvature of the margin. Three cases of occlusal chipping were found. The margin of dental all-ceramic single-tooth restorations was the area of fracture origin. The fracture features were similar for zirconia, glass-ceramic, and alumina single-tooth restorations. Design features seem to be of great importance for fracture initiation.
Assuntos
Cerâmica/química , Coroas , Materiais Dentários/química , Falha de Restauração Dentária , Restaurações Intracoronárias , Zircônio/química , Óxido de Alumínio/química , Cimentos Dentários/química , Porcelana Dentária/química , Facetas Dentárias , Humanos , Teste de Materiais , Microscopia , Microscopia Eletrônica de Varredura , Propriedades de Superfície , Fatores de TempoRESUMO
PURPOSE: This study investigated whether the tubular occluding effect of oxalate desensitizer (OX) during adhesive cementation (three resin cements) influenced fracture resistance of teeth restored with adhesive inlays. MATERIALS AND METHODS: Ninety intact maxillary premolars were randomly divided into 9 groups of 10 each. The two control groups were Gr 1, intact teeth and Gr 2, mesio-occlusodistal preparation only. In six experimental groups, the composite inlays were cemented with ED Primer II/Panavia F 2.0, Excite DSC/Variolink II, and One-Step Plus/Duolink according to manufacturers' instructions (Groups 3, 5, and 7, respectively) or with OX during cementation (Groups 4, 6, and 8, respectively). In Group 9, inlays were cemented with a resin cement without adhesive system. After thermocycling, fracture strength was tested. The data were analyzed using two-way and one-way ANOVA and LSD post hoc tests (α = 0.05). RESULTS: Fracture resistance of the six groups were significantly affected by OX (p = 0.002) but not by the resin cement type (p > 0.05). The interaction of the two factors was statistically significant (p = 0.052). A statistically significant difference between all groups was found (p < 0.001). The mean fracture resistances (N) were: Gr1 = 1168 ± 157,(a) Gr2 = 360 ± 110,(d) Gr3 = 1026 ± 188,(b) Gr4 = 887 ± 143,(c) Gr5 = 1007 ± 132,(b) Gr6 = 810 ± 164,(c) Gr7 = 1033 ± 218,(a) Gr8 = 955 ± 147,(ab) Gr9 = 780 ± 86(c) (groups with the same superscript letter indicate statistical similarity). CONCLUSIONS: Combining an OX with three resin cements had a significant negative effect on the fracture resistance of premolars restored with composite inlay cemented with Panavia F2.0 and Variolink II, but it had no significant effect when cemented with Duolink.
Assuntos
Resinas Compostas/química , Materiais Dentários/química , Dessensibilizantes Dentinários/química , Restaurações Intracoronárias , Oxalatos/química , Cimentos de Resina/química , Fraturas dos Dentes/fisiopatologia , Óxido de Alumínio/química , Dente Pré-Molar/ultraestrutura , Cimentação/métodos , Preparo da Cavidade Dentária/instrumentação , Preparo da Cavidade Dentária/métodos , Corrosão Dentária/métodos , Falha de Restauração Dentária , Dentina/ultraestrutura , Adesivos Dentinários/química , Humanos , Teste de Materiais , Metacrilatos/química , Distribuição Aleatória , Propriedades de Superfície , Temperatura , Fatores de TempoRESUMO
UNLABELLED: OBJECTIVE. This study evaluated the influence of restorative techniques on the fracture load and fracture mode of endodontically treated premolars with MOD cavities. MATERIALS AND METHODS: Sixty maxillary premolars were divided into groups: G1 - sound teeth; G2 - direct technique using Four Season; G3 - Adoro inlays; G4 - Adoro onlays; G5 - Empress inlays; G6 - Empress onlays. The specimens were submitted to compressive axial loading until failure. The fracture mode was analyzed. RESULTS. According to ANOVA and Tukey's test (α=0.05), the sound teeth (1370.61 N) showed the highest fracture load mean, which did not differ statistically from IPS Empress onlays (1304.21 N). Intermediate values were obtained for IPS Empress inlays (918.76 N), Adoro onlays (861.15 N), Adoro inlays (792.71 N) which did not differ statistically among them. The lowest fracture load was obtained for direct restorations with Four Seasons (696.08 N), which did not differ statistically from the Adoro inlays. CONCLUSIONS. The ceramic restorations provided higher fracture load and more incidences of catastrophic fractures. Cuspal coverage increased teeth fracture load. The results were similar for direct and indirect inlays with composite resin.
Assuntos
Dente Pré-Molar/fisiopatologia , Restauração Dentária Permanente/métodos , Fraturas dos Dentes/fisiopatologia , Dente não Vital/terapia , Condicionamento Ácido do Dente/métodos , Óxido de Alumínio/química , Silicatos de Alumínio/química , Resinas Compostas/química , Preparo da Cavidade Dentária/métodos , Corrosão Dentária/métodos , Materiais Dentários/química , Porcelana Dentária/química , Análise do Estresse Dentário/instrumentação , Humanos , Restaurações Intracoronárias , Cura Luminosa de Adesivos Dentários , Metacrilatos/química , Ácidos Fosfóricos/química , Cimentos de Resina/química , Estresse Mecânico , Dente não Vital/fisiopatologiaRESUMO
AIM: To investigate the benefits of pulpotomy (to the level of the floor of the pulp chamber) as an endodontic treatment for teeth with vital pulps. METHODOLOGY: Seventeen patients, aged 7-54 years (mean of 37.2 year), were treated by pulpotomy and filling with ProRoot MTA(®) in premolar or molar teeth with vital pulps and without clinical evidence of irreversible pulpitis. The patients were then followed up for 12 to 24 months and the teeth then assessed by clinical and radiographic examination. Statistical analysis was performed with Kaplan-Meier survival probability statistics to estimate the survival of the treated teeth. RESULTS: At 24 months, the survival rate without any complementary treatment was estimated to be 82%. Two of the 17 treated teeth required root canal treatment for pain control and one for prosthetic reasons. CONCLUSIONS: Under the conditions of this study, pulpotomy offered a viable alternative to root canal treatment for teeth with vital pulps in the short term. However, there is insufficient clinical evidence to consider this technique for the treatment of every permanent tooth. Nevertheless, it should be considered as a potential alternative approach to be further developed for future applications.
Assuntos
Pulpotomia/métodos , Adolescente , Adulto , Compostos de Alumínio/uso terapêutico , Dente Pré-Molar/diagnóstico por imagem , Dente Pré-Molar/patologia , Compostos de Cálcio/uso terapêutico , Criança , Resinas Compostas/química , Coroas , Cárie Dentária/terapia , Materiais Dentários/química , Polpa Dentária/diagnóstico por imagem , Polpa Dentária/patologia , Cavidade Pulpar/diagnóstico por imagem , Cavidade Pulpar/patologia , Teste da Polpa Dentária , Combinação de Medicamentos , Feminino , Seguimentos , Humanos , Restaurações Intracoronárias , Masculino , Pessoa de Meia-Idade , Dente Molar/diagnóstico por imagem , Dente Molar/patologia , Óxidos/uso terapêutico , Medição da Dor , Técnica para Retentor Intrarradicular , Agentes de Capeamento da Polpa Dentária e Pulpectomia/uso terapêutico , Radiografia , Silicatos/uso terapêutico , Taxa de Sobrevida , Adulto JovemRESUMO
BACKGROUND: The forehead, which occupies about one third of the face, is one of the major determinants of a feminine or masculine look. Various methods have been used for the augmentation of the forehead using autologous fat grafts or alloplastic materials. Methylmethacrylate (MMA) is the most appropriate material for augmentation of the forehead, and we have used an injection-molding technique with MMA to achieve satisfactory results. METHODS: Under local anesthesia with intravenous (IV) sedation, an incision was made on the scalp and a meticulous and delicate subperiosteal dissection was then performed. MMA monomers and polymers were mixed, the dough was injected into the space created, and manual molding was performed along with direct inspection. This surgery was indicated for patients who wanted to correct an unattractive appearance by forehead augmentation. Every patient in this study visited our clinics 3 months after surgery to evaluate the results. We judged the postoperative results in terms of re-operation rates caused by the dissatisfaction of the patients and complications. RESULTS: During a 13-year period, 516 patients underwent forehead augmentation with MMA. With the injection-molding technique, the inner surface of the MMA implant is positioned close to the underlying frontal bone, which minimizes the gap between the implant and bone. The borders of the implant should be tapered sufficiently until no longer palpable or visible. Only 28 patients (5.4%) underwent a re-operation due to an undesirable postoperative appearance. CONCLUSIONS: The injection-molding technique using MMA is a simple, safe, and ideal method for the augmentation of the forehead.
Assuntos
Humanos , Anestesia Local , Testa , Osso Frontal , Fungos , Restaurações Intracoronárias , Metilmetacrilato , Polímeros , Couro Cabeludo , Cirurgia Plástica , TransplantesRESUMO
OBJECTIVES: Comparative studies of bone remodelling and mechanical stresses between inlay and onlay fixed partial dentures (FPD) are rather limited. The purpose of this paper was to evaluate the biological consequence in posterior mandibular bone and the mechanical responses in these two different prosthetic configurations. METHODS: Three-dimensional (3D) finite element analysis (FEA) models are created to explore the mechanical responses for the inlay and onlay preparations within the same oral environment. Strain induced bone remodelling was simulated under mastication. The remodelling adopted herein relates the strain in the bone to the change of Hounsfield Unit (HU) value in proportion to the surface area density (SAD) of bony morphology, which allows directly correlating to clinical computerised tomography (CT) data. RESULTS: The results show that both FPD designs exhibit a similar resultant change in bone mineral density (BMD) though the onlay configuration leads to a more uniform distribution of bone density. The inlay design results in higher mechanical stresses whilst allowing preservation of healthy tooth structure. CONCLUSIONS: This study provides an effective means to further clinical assessment and investigation into biomechanical responses and long-term restorative outcome with different FPD designs. CLINICAL SIGNIFICANCE: Quantifying in vivo stress distributions associated with inlay/onlay FPDs can further supplement clinical investigations into prosthetic durability, FPD preparation techniques (i.e., taper angles, material development), consequent stress distributions and the ongoing biomechanical responses of mandibular bone.
Assuntos
Remodelação Óssea , Porcelana Dentária , Análise do Estresse Dentário , Restaurações Intracoronárias , Mandíbula/fisiologia , Dente Pré-Molar , Fenômenos Biomecânicos , Força de Mordida , Densidade Óssea , Simulação por Computador , Dente Suporte , Planejamento de Prótese Dentária , Análise do Estresse Dentário/métodos , Módulo de Elasticidade , Análise de Elementos Finitos , Humanos , Mandíbula/diagnóstico por imagem , Dente Molar , Estresse Mecânico , Tomografia Computadorizada por Raios XRESUMO
MgO, SiO(2), Al(2)O(3), MgF(2), CaF(2), CaCO(3), SrCO(3), and P(2)O(5) were used to prepare glass-ceramics for restorative dental materials. Thermal properties, phases, microstructures and hardness were characterized by DTA, XRD, SEM and Vickers microhardness. Three-point bending strength and fracture toughness were applied by UTM according to ISO 6872: 1997(E). XRD showed that the glass crystallized at 892°C (second crystallization temperature+20°C) for 3 hrs consisted mainly of calcium-mica and fluorapatite crystalline phases. Average hardness (3.70 GPa) closely matched human enamel (3.20 GPa). The higher fracture toughness (2.04 MPaâm) combined with the hardness to give a lower brittleness index (1.81 µm(-1/2)) which indicates that they have exceptional machinability. Bending strength results (176.61 MPa) were analyzed by Weibull analysis to determine modulus value (m=17.80). Machinability of the calcium mica-fluorapatite glass-ceramic was demonstrated by fabricating with CAD/CAM.
Assuntos
Cerâmica/química , Materiais Dentários/química , Óxido de Alumínio/química , Silicatos de Alumínio/química , Apatitas/química , Carbonato de Cálcio/química , Fluoreto de Cálcio/química , Carbonatos/química , Desenho Assistido por Computador , Cristalização , Esmalte Dentário/ultraestrutura , Adaptação Marginal Dentária , Análise Diferencial Térmica , Módulo de Elasticidade , Fluoretos/química , Dureza , Temperatura Alta , Humanos , Restaurações Intracoronárias , Compostos de Magnésio/química , Óxido de Magnésio/química , Teste de Materiais , Microscopia Eletrônica de Varredura , Transição de Fase , Compostos de Fósforo/química , Maleabilidade , Dióxido de Silício/química , Estresse Mecânico , Estrôncio/química , Temperatura , Fatores de Tempo , Difração de Raios XRESUMO
OBJECTIVES: The purpose of this prospective study was to evaluate the clinical outcome of inlay-retained fixed dental prostheses (IRFDPs) with a new design made from a zirconia ceramic. METHODS: Twenty-three 3-unit IRFDPs were placed in 23 patients, restoring five second premolars and 18 first molars. Preparations were performed in accordance with general principles for ceramic inlay restorations and modified with a retainer-wing bevel preparation in the enamel at the buccal and oral sides. The frameworks were scanned and milled out of zirconia ceramic, using the InLab CAD/CAM-system and the pontics were veneered with feldspathic ceramic. All IRFDPs were luted adhesively with composite resin. Clinical follow-up examinations were performed annually. Statistical analysis was performed using descriptive statistics and Kaplan-Meier survival analysis. RESULTS: All patients with their 23 IRFDPs could be examined clinically after a mean observation time of 20 months. None of the IRFDPs failed. Two ceramic veneers fractured, both of them needed repair. One restoration debonded, but was recemented immediately. However, these technical complications did not affect the clinical function of the IRFDPs involved. CONCLUSIONS: The clinical outcome of zirconia ceramic IRFDPs with the modified design seems promising.
Assuntos
Porcelana Dentária/química , Planejamento de Dentadura , Retenção de Dentadura , Prótese Parcial Fixa , Restaurações Intracoronárias , Zircônio/química , Condicionamento Ácido do Dente/métodos , Adulto , Óxido de Alumínio/química , Silicatos de Alumínio/química , Cimentação/métodos , Resinas Compostas/química , Desenho Assistido por Computador , Dente Suporte , Esmalte Dentário/patologia , Reparação em Prótese Dentária , Facetas Dentárias , Feminino , Seguimentos , Humanos , Masculino , Fosfatos/química , Compostos de Potássio/química , Estudos Prospectivos , Cimentos de Resina/química , Propriedades de Superfície , Preparo do Dente/métodos , Resultado do TratamentoRESUMO
AIM: The aim of this study was to evaluate the in vitro fracture resistance of teeth restored with bonded ceramic inlay and direct composite resin restoration in comparison to the normal tooth. MATERIALS AND METHODS: This study evaluated the fracture strength of the teeth restored with bonded ceramic inlay and direct composite resin restoration in comparison to the normal teeth. Thirty intact human maxillary first premolars were assigned to three groups: Group 1 - comprising sound/unprepared teeth (control). Group 2 - comprising of Class-II direct composite resin restored teeth and Group 3 - comprising Class-II ceramic inlay restored teeth. Cavities were prepared with occlusal width of 1/3 intercuspal distance and 2 mm deep pulpally. Group 2 teeth were restored with hybrid composite resin (Z350 3M ESPE, USA) and group 3 teeth were restored with Vitadur Alpha alumina (Ivoclare Vivadent, Liechtenstein, Europe). Ceramic inlay was bonded with adhesive cement (rely X resin cement of 3MESPE, USA). The specimens were subjected to a compressive load until they fractured. Data were analyzed statistically by unpaired Student's t test. RESULTS: The fracture resistant strength, expressed as kilonewton (KN), was group 1 - 1.51 KN, group 2 - 1.25 KN, and group 3 - 1.58 KN. Statistically, group III had highest fracture resistance followed by group I, while group II had the lowest average fracture resistance. CONCLUSION: The fracture resistant strength of teeth restored with ceramic inlay was comparable to that of the normal intact teeth or slightly higher, while teeth restored with direct composite resin restoration showed less fracture resistant strength than that of the normal teeth.
Assuntos
Resinas Compostas/química , Materiais Dentários/química , Porcelana Dentária/química , Planejamento de Prótese Dentária , Restaurações Intracoronárias , Fraturas dos Dentes/fisiopatologia , Condicionamento Ácido do Dente/métodos , Óxido de Alumínio/química , Bis-Fenol A-Glicidil Metacrilato/química , Colagem Dentária/métodos , Preparo da Cavidade Dentária/classificação , Análise do Estresse Dentário/instrumentação , Adesivos Dentinários/química , Cimentos de Ionômeros de Vidro/química , Humanos , Ácido Fluorídrico/química , Restaurações Intracoronárias/classificação , Teste de Materiais , Ácidos Fosfóricos/química , Cimentos de Resina/química , Estresse Mecânico , Temperatura , Fatores de Tempo , Dente/fisiologia , Água/químicaRESUMO
The plethora of ceramic systems available today for all types of indirect restorations can be confusing--and overwhelming--for the clinician. Having a better understanding of them is key. The authors use classification systems based on the microstructural components of ceramics and the processing techniques to help illustrate the various properties and uses.
Assuntos
Porcelana Dentária/química , Porcelana Dentária/classificação , Óxido de Alumínio , Silicatos de Alumínio , Desenho Assistido por Computador , Coroas , Planejamento de Prótese Dentária , Humanos , Restaurações Intracoronárias , Compostos de Lítio , Compostos de Potássio , Dióxido de Silício , ZircônioRESUMO
OBJECTIVES: To assess the influence of restorative materials and load cusps on the fatigue resistance of endodontically treated molars. METHOD AND MATERIALS: Thirty extracted molars received root canal treatment followed by a standardized tooth preparation (3-mm cuspal reduction and immediate dentin sealing). Twenty Cerec 3 overlays (Sirona Dental Systems) were milled in the ceramic Vita MKII block (Vident; groups MKIIGL and MKIIGL-Z, oven-glazed), and 10 restorations were duplicated with a composite resin (Miris 2, Coltane/Whaledent; group M2). The fitting surfaces of the restorations were hydrofluoric acid etched (porcelain only) and silanated. Preparations were airborne-particle abraded and etched. All restorations were luted with preheated Filtek Z100 (3M ESPE) and subjected to cyclic isometric chewing (5 Hz) starting at 200 N (5,000 cycles), followed by stages of 400, 600, 800, 1,000, 1,200, and 1,400 N at a maximum of 30,000 cycles each. A stainless steel load sphere was used for groups MKIIGL and M2, while a composite resin load sphere was used in group MKIIGL-Z. All samples were loaded until fracture or to a maximum of 185,000 cycles. Groups were compared using the Kaplan-Meier survival curves (P = .05). RESULTS: None of the molars restored with porcelain withstood all 185,000 loading cycles (survival = 0%). The mean fracture load for MKIIGL was 1,060 N and for MKIIGL-Z, 1,280 N. In group M2, the survival rate was 50%. The rate of fracture below the CEJ was 40%, 30%, and 20% for MKIIGL, MKIIGL-Z, and M2, respectively. CONCLUSION: Miris 2 overlays showed higher fatigue resistance than MKII porcelain (P = .01) when loaded with a stainless steel antagonist.
Assuntos
Materiais Dentários/química , Planejamento de Prótese Dentária , Restaurações Intracoronárias , Dente Molar/fisiopatologia , Dente não Vital/fisiopatologia , Condicionamento Ácido do Dente , Óxido de Alumínio/química , Força de Mordida , Resinas Compostas/química , Desenho Assistido por Computador , Colagem Dentária , Corrosão Dentária , Porcelana Dentária/química , Falha de Restauração Dentária , Humanos , Ácido Fluorídrico/química , Teste de Materiais , Tratamento do Canal Radicular , Silanos/química , Dióxido de Silício/química , Aço Inoxidável/química , Estresse Mecânico , Análise de Sobrevida , Fatores de Tempo , Preparo do Dente/métodos , Zircônio/químicaRESUMO
The purpose of the current study was to evaluate the color stability of two indirect composite materials (Sinfony and Pearleste) polymerized with different laboratory polymerization systems. Disk specimens were prepared with their proprietary polymerization systems (Visio and Pearlcure systems) or with a metal halide light polymerization unit (Hyper LII) for 60, 120, and 180 s. After storage at 37 degrees C for 24 h, the specimens were immersed in either purified water or tea. Color change between baseline evaluation and after 4 weeks was determined with a dental chroma meter (ShadeEye NCC) using black and white backgrounds. CIE 1976 L(*)a(*)b(*) values were determined, and they were converted into DeltaE(*)(ab) values. The DeltaE(*)(ab) value of the Sinfony material immersed in tea was the highest when the material was polymerized with the proprietary Visio system. The Pearleste material immersed in purified water and tea was not affected substantially by the polymerization systems. Among the 12 groups polymerized with the Hyper LII units, DeltaE(*)(ab) values of 11 groups were significantly lower for the Pearleste material than for the Sinfony material. It can be concluded that the Pearleste material was stable against color change when the material was polymerized with either the Pearlcure system or with the Hyper LII unit.