RESUMEN
OBJECTIVES: To prove the biocompatibility of biomaterials applied in biomedical devices, in vitro testing is crucial to render a material fit for medical application. The material of choice for dental implants is commercially pure titanium (cp-Ti), while other materials such as zirconia and polyetheretherketone (PEEK) are considered highly promising due to their functional and esthetic properties. The aim of this study was to determine whether PEEK with defined mean surface roughness and composition could achieve results equal to titanium or zirconia. MATERIALS AND METHODS: Disks measuring 14 mm in diameter and 1 mm in thickness made from cp-Ti, yttria-stabilized zirconia (Y-TZP), and filled PEEK with a smooth surface finish were used for cell culture experiments. Human fetal osteoblasts (hFOB) were cultured in vitro on each material to observe changes after 1, 3, and 7 days regarding cell viability and lactate dehydrogenase (LDH) release. Additionally, mRNA expression of proliferative factors PCNA and Ki67 and cellular adhesion (vinculin mRNA expression and immunofluorescence staining) were analyzed after 3 days in the culture. RESULTS: In hFOB cultures, adhesion and viability were decreased on PEEK platelets, while LDH release remained stable. No significant difference was observed in cp-Ti and Y-TZP when compared to the control. CONCLUSIONS: The performance of cp-Ti and Y-TZP was equal to the control in all tests. It seems that highly polished PEEK in this particular composition cannot be recommended for osseointegrated implant applications due to decreased osteoblast attachment. Further investigations are recommended, especially in surface structures optimized for osseointegration.
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Adhesión Celular , Osteoblastos/fisiología , Propiedades de Superficie , Benzofenonas , Supervivencia Celular , Células Cultivadas , Humanos , Cetonas , Microscopía Electrónica de Rastreo , Polietilenglicoles , Polímeros , Titanio , Itrio , CirconioRESUMEN
OBJECTIVE: This study compared the loosening torque of experimental double conical abutment screws to that of conventional conical abutment screws and flat-head screws in implants with internal connections before and after mechanical loading. MATERIAL AND METHODS: Eighty implant-screw-abutment assemblies were divided into four groups: flat-head screw (Xive S), conical screw (Straumann), conical screw (Nobel Biocare), and double conical screw (RTB). Abutments were tightened to a torque of 30 Ncm. After 10 min, they were retightened and loosening torque was measured. The same abutments were then retightened with new screws to a torque of 30 Ncm and, again, retightened after 10 min. They were then mechanically loaded for 3 000 000 cycles, and loosening torque was again measured. Data were collected, and an exploratory analysis was performed. RESULTS: Comparisons before mechanical cycling showed significant differences between groups. After mechanical cycling, only the comparisons of Straumann and Nobel Biocare showed no significant differences. Considering the same group before and after mechanical cycling, all comparisons showed significant differences. CONCLUSION: The shape of the abutment screw head significantly influenced loosening torque: Double conical-head screws showed significantly higher loosening torque values than conical-head screws. Conical-head screws showed higher loosening torque values than conventional flat-head screws before and after loading.
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Tornillos Óseos , Pilares Dentales , Implantes Dentales , Análisis del Estrés Dental , Humanos , TorqueRESUMEN
OBJECTIVES: Aim of this controlled prospective randomized study was to evaluate the outcome of two-piece zirconia implants compared to titanium implants over a period of up to 24 months. MATERIAL AND METHODS: A total of 31 implants (16 zirconia/Ziterion vario Z(®) + 15 titanium/Ziterion vario T(®) ) were inserted primary stable (>30 Ncm) in the maxilla (7) and mandible (24) of 22 patients (13 male, nine female) requiring neither bone nor soft tissue augmentation. After a healing period of 6 months in the maxilla and 4 months in the mandible, ceramic abutments were luted adhesively to the zirconia implants and definitive all-ceramic restoration was performed with high-density ceramics. Radiographic bone levels, condition of the peri-implant mucosa, aesthetic outcome, implant survival and success were recorded for up to 24 months. RESULTS: Measurements of mean marginal bone levels 24 months after surgery showed a significant bone loss (P < 0.001) in both groups (Ti: 1.43 (SD ± 0.67) vs. Zir 1.48 (SD ± 1.05). One zirconia implant was lost 8 months after restoration. No further complications were recorded, giving an overall survival and success rate of 93.3% for zirconia and 100% for titanium implants after a period of up to 24 months. CONCLUSIONS: After 24 months, success rates of the two-piece ceramic implants showed no significant difference compared to control two-piece titanium implants. The bonded zirconia implant abutment connection appears to be capable with clinical application over the observed period. However, further control measurements need to confirm the presented data.
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Cerámica/química , Implantes Dentales de Diente Único , Restauración Dental Permanente/métodos , Titanio/química , Circonio/química , Adulto , Anciano , Pérdida de Hueso Alveolar/diagnóstico , Diseño de Prótesis Dental , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Estudios Prospectivos , Resultado del Tratamiento , Cicatrización de HeridasRESUMEN
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.
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Recubrimiento Dental Adhesivo , Grabado Dental/métodos , Dentina/ultraestructura , Resinas Acrílicas/química , Óxido de Aluminio/química , Silicatos de Aluminio/química , Carbonato de Calcio/química , Resinas Compuestas/química , Cementos Dentales/química , Materiales Dentales/química , Análisis del Estrés Dental/instrumentación , Glicina/química , Humanos , Imagenología Tridimensional/métodos , Incrustaciones , Curación por Luz de Adhesivos Dentales/métodos , Ensayo de Materiales , Compuestos de Potasio/química , Cementos de Resina/química , Resistencia al Corte , Silanos/química , Silicatos/química , Estrés Mecánico , Propiedades de Superficie , Temperatura , Factores de Tiempo , Óxido de Zinc/químicaRESUMEN
OBJECTIVE: Aim of this prospective case series was to evaluate the outcome of immediately provisionalized single-piece zirconia implants. MATERIAL AND METHODS: A total of 20 zirconia implants were inserted in single-tooth gaps in the maxilla (11) and mandible (9) of 20 patients. Implants were restored with all-ceramic CAD/CAM provisionals without occlusal contacts immediately after placement. Permanent all-ceramic restoration was performed 4 months after surgery. Plaque index (PI), bleeding on probing (BOP), Periotest(®) (PV), pink aesthetic score (PES), mean radiographic marginal bone levels (MBL), implant survival and success were evaluated up to 24 months. RESULTS: Assessment of PI at baseline and follow-ups after 6, 12, 18 and 24 months revealed 27% (±5.3), 24% (±6), 23% (±6.1), 23% (±5.3) and 22% (±6.4), respectively. Evaluation of BOP revealed 25% (±5.6), 21% (±6), 21% (±7.2), 18% (±5.9) and 15% (±5.5), respectively. Implants presented stable at follow-ups (PV). PES improved, but not statistically significant from 8.13 (±1.5) at baseline to 10 (±2) 24 months after implantation. Measurements of MBL showed a significant bone loss of 1.01 mm within the first year after placement (P < 0.001) and 1.29 mm 24 months post-implant insertion, not reaching further statistically significant levels (P > 0.05). One implant was lost 4 months after placement, resulting in a survival and success rate of 95%. CONCLUSION: Clinical and radiographic parameters demonstrated a 95% integration of immediately loaded zirconia single-piece implants. A long-term randomized-controlled clinical trial was initiated to confirm evidence of this protocol.
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Implantes Dentales de Diente Único , Carga Inmediata del Implante Dental , Adulto , Anciano , Índice de Placa Dental , Diseño de Prótesis Dental , Fracaso de la Restauración Dental , Femenino , Humanos , Masculino , Persona de Mediana Edad , Índice Periodontal , Proyectos Piloto , Estudios Prospectivos , Radiografía Dental , Resultado del Tratamiento , CirconioRESUMEN
STATEMENT OF PROBLEM: Data are needed to better predict the color stability of current composite resin materials. PURPOSE: The purpose of this study was to evaluate the impact of different storage solutions on the color stability of different composite resin materials. MATERIAL AND METHODS: Different restorative and adhesive composite resin specimens (dual-polymerizing self-adhesive resin cement, autopolymerizing resin-based composite resin, dual-polymerizing resin-based composite resin, nanohybrid composite resin, and microhybrid composite resin) were fabricated and stored in red wine, black tea, chlorhexidine, sodium fluoride, tea tree oil, or distilled water for 4 weeks at 37°C. Color parameters were measured with a colorimeter before and after storage. Total color differences and specific coordinate differences were expressed as ΔE, ΔL, Δa, and Δb. A 2-way and 1-way analysis of variance (ANOVA) with Bonferroni adjustment for multiple comparisons were applied for statistical calculations (α=.05). RESULTS: Red wine caused the most severe discoloration (ΔE >10), followed by black tea with perceptible (ΔE >2.6) to clinically unacceptable discoloration (ΔE >5.5). Colored mouth rinses discolored the materials to a lesser extent with clinically acceptable values. Dual-polymerizing resin adhesives showed a higher amount of discoloration. CONCLUSIONS: Current restorative and adhesive composite resin materials discolor over time under the influence of different storage solutions. The composition related to the polymerizing mode seemed to be a causative factor.
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Color , Resinas Compuestas , Coloración de Prótesis , Resinas Compuestas/química , Ensayo de Materiales , Nanocompuestos , Aceites de Plantas , Polimerizacion , Fluoruro de Sodio , Espectrofotometría , Té , VinoRESUMEN
OBJECTIVE: To investigate the oral state in participants cared for in residences for senior citizens in Styria, Austria. MATERIALS AND METHODS: Four hundred and nine participants in Styria from nine homes for senior citizens were examined employing parameters in accordance with those of Folstein's Mini Mental Status (MMS), DMFT, basic periodontal examination, the modified oral hygiene index, pain experienced during the preceding year, the subjective and objective need for treatment, and also requirements involving surgical and prosthetic treatment. Furthermore, the habitual methods of maintaining oral hygiene were examined establishing by whom this was carried out - whether by the patient, the nurse, or by patient and nurse together. RESULTS: Four hundred and nine participants were examined, 48.3% were found to have retained on average 4.9 of their own teeth while 69% were fitted with dentures; however, 81% of the participants required prosthetic treatment. 28.9% of the participants had experienced acute dental pain during the preceding year and surgical treatment was found to be necessary in 47.7% of those with original teeth. Eighty-four per cent of the participants showed acute inflammation of the periodontium while the state of oral hygiene, measured on a scale of 0-4, reached an average of 2.43. Oral hygiene was carried out by the nurses in only 7.46% of the cases which showed an average MMS measurement of 18. CONCLUSION: The results compared with those reported in other recent surveys and our data show an urgent need in Austria to improve the standards in dental care for the hospitalised elderly. Regular dental checks, carried out in the actual home by a dental surgeon should be introduced, whilst the nursing staff should be made fully aware of the problems caused by insufficient oral care and receive regular support from specialised oral hygiene assistants. The results of this survey also suggest that nursing staff should be equipped with simple instruments in order to judge to the extent to which the patient is capable of carrying out oral care independently and then according to the results to supplement this with additional care.
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Hogares para Ancianos/estadística & datos numéricos , Casas de Salud/estadística & datos numéricos , Enfermedades Periodontales/epidemiología , Enfermedades Dentales/epidemiología , Anciano , Anciano de 80 o más Años , Austria/epidemiología , Índice CPO , Cuidado Dental para Ancianos/estadística & datos numéricos , Prótesis Dental/estadística & datos numéricos , Femenino , Estado de Salud , Humanos , Arcada Parcialmente Edéntula/epidemiología , Masculino , Escala del Estado Mental , Persona de Mediana Edad , Evaluación de Necesidades/estadística & datos numéricos , Salud Bucal , Higiene Bucal/estadística & datos numéricos , Índice de Higiene Oral , Procedimientos Quirúrgicos Orales/estadística & datos numéricos , Índice Periodontal , Periodontitis/epidemiología , Odontalgia/epidemiologíaRESUMEN
OBJECTIVES: To evaluate the influence of gender and level of experience on shade matching quality. METHODS: A study was simultaneously performed at 15 universities located in 9 countries. A total of 614 color normal participants completed all phases of the experiment. Among them, there were 305 females and 309 males, 319 dental students and 295 dental professionals. A lecture on color matching in dentistry was given to all participants. Initial training was performed using Toothguide Trainer software (TT), while Toothguide Training Box (TTB) was used for both training and testing of participants' shade matching results. The test task was to successively match 15 shade guide tabs with the corresponding shade guide. The shade matching score for each participant was computed as a sum of color differences (SigmaDeltaE(ab)(*) score) between target tabs and selected tabs. Lower scores corresponded to better shade matching results and vice versa. Means and standard deviations were calculated. Mann-Whitney U test was used for statistical analysis of the data (alpha=0.05). RESULTS: The mean shade matching score (S.D.) for all participants was 41 (21). The score for female and male participants was 38 (20) and 44 (21), respectfully (p<0.001). The difference in scores between dental students, 42 (20), and dental professionals, 39 (21), was not statistically significant. CONCLUSION: Within the limitations of this study, females achieved significantly better shade matching results than males, indicating that gender plays an important role in shade matching. The level of experience was not found to be significant factor in shade matching.
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Competencia Clínica/estadística & datos numéricos , Color/normas , Diseño de Prótesis Dental/estadística & datos numéricos , Odontólogas/estadística & datos numéricos , Odontólogos/estadística & datos numéricos , Coloración de Prótesis/estadística & datos numéricos , Adolescente , Adulto , Percepción de Color , Diseño de Prótesis Dental/normas , Restauración Dental Permanente/métodos , Restauración Dental Permanente/estadística & datos numéricos , Discriminación en Psicología , Estética Dental , Femenino , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Coloración de Prótesis/normas , Factores Sexuales , Estudiantes de Odontología/estadística & datos numéricos , Adulto JovenRESUMEN
This article describes a procedure in which an obturator with an integrated spring-loaded rewinding device retains an orbital prosthesis. This system minimizes movement of the orbital prosthesis during mastication and thus prevents adhesive failure.