RESUMO
INTRODUCTION: The purposes of this study were to assess the role of dental attractiveness in background facial attractiveness and to evaluate how facial and dental attractiveness influenced raters' opinions of the integrity, social attractiveness, and intellectual attractiveness of the models. METHODS: Photographs of male and female individuals rated by peers as unattractive, average, and attractive were combined with oral images of 4 different levels of dental attractiveness (Index of Orthodontic Treatment Need [IOTN] 1, 5, 7, and 10). Sixty-seven participants meeting the inclusion criteria were recruited as raters. Raters viewed closed-lip smile and open-lip, posed smile of 24 models and rated them for facial attractiveness and integrity and multiple social/intellectual attractiveness dimensions using a Visual Analog Scale. RESULTS: Intrarater reliability was fair to excellent. Analysis of variance showed significant 3-way interactions (P < 0.0001=aim 1; P < 0.005=aim 2) for model sex, facial attractiveness, and dental attractiveness. The contribution of dental attractiveness to facial attractiveness was not fixed or linear, but dependent on dental attractiveness level, background facial attractiveness, and model sex. For both sexes, dental impact on facial attractiveness was neutral or negative when teeth were less than ideal, beginning at IOTN 5 for all background facial attractiveness levels. The impact of dental attractiveness on integrity and social and intellectual attractiveness was also dependent on dental attractiveness level, background facial attractiveness, and model sex. Dental attractiveness can make dramatic differences in Average and Attractive male individuals. CONCLUSIONS: The impact of dental attractiveness on facial attractiveness and integrity and social and intellectual attractiveness was dependent on dental attractiveness level, background facial attractiveness, and model sex. The effect of dental esthetics on facial attractiveness was neutral or negative for both male and female individuals when there was a need for treatment (IOTN 5 or higher) for all levels of facial attractiveness. For both male and female models, lower dental esthetics had a greater effect on more attractive faces. Judgments about integrity and social and intellectual attractiveness were strongly affected by dental esthetics, and these effects were more dramatic and consistent for male faces.
Assuntos
Beleza , Estética Dentária/psicologia , Índice de Necessidade de Tratamento Ortodôntico , Má Oclusão/classificação , Má Oclusão/psicologia , Sorriso/psicologia , Desejabilidade Social , Adolescente , Adulto , Feminino , Humanos , Masculino , Fotografação , Reprodutibilidade dos Testes , Escala Visual AnalógicaRESUMO
STATEMENT OF PROBLEM: Whether deviations in alignment discrepancy, width-to-length ratio, application of the golden proportion, or number of teeth revealed in smile affect attractiveness is yet unknown. PURPOSE: The purpose of this analytical study was to quantify dental and facial esthetics to determine whether individuals identified as having superior smiles display differences in alignment discrepancies (angulation between interpupillary and commissure line); width-to-length ratios of maxillary anterior teeth; application of the golden proportion (approximately 1.618:1); and number of teeth revealed in an animated smile when compared with an average population. MATERIAL AND METHODS: An Internet search for "best smile" and "celebrity" identified 108 celebrities. Photographs showing smiles within 10 degrees of a frontal view were collected, while photographs of dental students were used for the control group. Alignment discrepancies, widths and lengths of the anterior teeth, and number of teeth revealed in an animated smile were measured with photo-editing software, and ratios were calculated. The groups were compared with repeated-measures ANOVA, the Mann-Whitney U test, and the Wilcoxon signed-rank test (α=.05). RESULTS: Usable photographs were obtained for 90 celebrities (58 women, 32 men) and compared with photographs of 97 dental students (54 women, 43 men). Statistically significant differences were found for alignment discrepancies (celebrities 0.97, students 1.25, P=.034) and for the number of teeth displayed (P=.049); 22.2% of the celebrities revealed 12 teeth, versus 6.2% of the students. In both groups, significant differences from the golden ratio (1.618:1) for the width of the central incisor/lateral incisor right and left and for the width of the lateral incisor/canine right and left were observed through 95% confidence intervals. Sex and left-right were nonsignificant factors. CONCLUSIONS: Celebrities identified as having a best smile had smaller mean alignment discrepancies and revealed a greater number of teeth in an animated smile than dental students.
Assuntos
Estética Dentária , Face/anatomia & histologia , Sorriso , Feminino , Humanos , Masculino , Fotografia Dentária , Dente/anatomia & histologiaRESUMO
INTRODUCTION: Recently, greater emphasis has been placed on smile esthetics in dentistry. Eye tracking has been used to objectively evaluate attention to the dentition (mouth) in female models with different levels of dental esthetics quantified by the aesthetic component of the Index of Orthodontic Treatment Need (IOTN). This has not been accomplished in men. Our objective was to determine the visual attention to the mouth in men with different levels of dental esthetics (IOTN levels) and background facial attractiveness, for both male and female raters, using eye tracking. METHODS: Facial images of men rated as unattractive, average, and attractive were digitally manipulated and paired with validated oral images, IOTN levels 1 (no treatment need), 7 (borderline treatment need), and 10 (definite treatment need). Sixty-four raters meeting the inclusion criteria were included in the data analysis. Each rater was calibrated in the eye tracker and randomly viewed the composite images for 3 seconds, twice for reliability. RESULTS: Reliability was good or excellent (intraclass correlation coefficients, 0.6-0.9). Significant interactions were observed with factorial repeated-measures analysis of variance and the Tukey-Kramer method for density and duration of fixations in the interactions of model facial attractiveness by area of the face (P <0.0001, P <0.0001, respectively), dental esthetics (IOTN) by area of the face (P <0.0001, P <0.0001, respectively), and rater sex by area of the face (P = 0.0166, P = 0.0290, respectively). For area by facial attractiveness, the hierarchy of visual attention in unattractive and attractive models was eye, mouth, and nose, but for men of average attractiveness, it was mouth, eye, and nose. For dental esthetics by area, at IOTN 7, the mouth had significantly more visual attention than it did at IOTN 1 and significantly more than the nose. At IOTN 10, the mouth received significantly more attention than at IOTN 7 and surpassed the nose and eye. These findings were irrespective of facial attractiveness levels. For rater sex by area in visual density, women showed significantly more attention to the eyes than did men, and only men showed significantly more attention to the mouth over the nose. CONCLUSIONS: Visual attention to the mouth was the greatest in men of average facial attractiveness, irrespective of dental esthetics. In borderline dental esthetics (IOTN 7), the eye and mouth were statistically indistinguishable, but in the most unesthetic dental attractiveness level (IOTN 10), the mouth exceeded the eye. The most unesthetic malocclusion significantly attracted visual attention in men. Male and female raters showed differences in their visual attention to male faces. Laypersons gave significant visual attention to poor dental esthetics in men, irrespective of background attractiveness; this was counter to what was seen in women.
Assuntos
Atenção , Beleza , Estética Dentária , Olho/anatomia & histologia , Face/anatomia & histologia , Adulto , Análise de Variância , Face/diagnóstico por imagem , Humanos , Índice de Necessidade de Tratamento Ortodôntico , Masculino , Má Oclusão/classificação , Má Oclusão/psicologia , Má Oclusão/terapia , Boca/anatomia & histologia , Nariz/anatomia & histologia , Reprodutibilidade dos Testes , Fatores Sexuais , Sorriso , Adulto JovemRESUMO
STATEMENT OF PROBLEM: Whether deviations in the angulation discrepancy between the intercanine and interpupillary line significantly affect attractiveness is unknown. PURPOSE: The purpose of this prospective study was to quantify dental and facial esthetics to determine whether smile angulation discrepancies in individuals identified as having attractive smiles are smaller than those in the average population. MATERIAL AND METHODS: An Internet search for "best smile" and "celebrity" identified 108 celebrities (Test group). Photographs showing smiles within 10 degrees of a frontal view were gathered. In mannequin testing, small head rotation (<10 degrees) was found not to affect the measurements. Photographs of dental students were used for the control group. The angulation discrepancy between the intercanine and interpupillary line was measured using computer software. Groups were compared using the Mann-Whitney U test (α=.05). RESULTS: Usable photographs were obtained for 94 celebrities (62 women, 32 men) and were compared with photographs of 97 dental students (54 women, 43 men). Significant (P<.01) differences in angulation discrepancy were found, with celebrities having smaller mean angulation discrepancies (0.97 degrees) than dental students (1.33 degrees). The differences between men and women were not statistically significant (P>.05). CONCLUSIONS: Celebrities identified as having "best smile" had significantly smaller mean angulation discrepancies than the control group.
Assuntos
Estética , Face/anatomia & histologia , Sorriso , Adulto , Pessoas Famosas , Feminino , Humanos , Masculino , Manequins , Fotografação , Estudos Prospectivos , Software , Estudantes de OdontologiaRESUMO
INTRODUCTION: Previous eye-tracking research has demonstrated that laypersons view the range of dental attractiveness levels differently depending on facial attractiveness levels. How the borderline levels of dental attractiveness are viewed has not been evaluated in the context of facial attractiveness and compared with those with near-ideal esthetics or those in definite need of orthodontic treatment according to the Aesthetic Component of the Index of Orthodontic Treatment Need scale. Our objective was to determine the level of viewers' visual attention in its treatment need categories levels 3 to 7 for persons considered "attractive," "average," or "unattractive." METHODS: Facial images of persons at 3 facial attractiveness levels were combined with 5 levels of dental attractiveness (dentitions representing Aesthetic Component of the Index of Orthodontic Treatment Need levels 3-7) using imaging software to form 15 composite images. Each image was viewed twice by 66 lay participants using eye tracking. Both the fixation density (number of fixations per facial area) and the fixation duration (length of time for each facial area) were quantified for each image viewed. Repeated-measures analysis of variance was used to determine how fixation density and duration varied among the 6 facial interest areas (chin, ear, eye, mouth, nose, and other). RESULTS: Viewers demonstrated excellent to good reliability among the 6 interest areas (intraviewer reliability, 0.70-0.96; interviewer reliability, 0.56-0.93). Between Aesthetic Component of the Index of Orthodontic Treatment Need levels 3 and 7, viewers of all facial attractiveness levels showed an increase in attention to the mouth. However, only with the attractive models were significant differences in fixation density and duration found between borderline levels with female viewers. Female viewers paid attention to different areas of the face than did male viewers. CONCLUSIONS: The importance of dental attractiveness is amplified in facially attractive female models compared with average and unattractive female models between near-ideal and borderline-severe dentally unattractive levels.
Assuntos
Beleza , Face/anatomia & histologia , Adolescente , Adulto , Movimentos Oculares , Feminino , Humanos , Índice de Necessidade de Tratamento Ortodôntico/estatística & dados numéricos , Má Oclusão , Adulto JovemRESUMO
STATEMENT OF PROBLEM: Different types of CAD/CAM systems are currently available, but information regarding which system produces the best marginal fit is lacking. PURPOSE: The purpose of this study was to evaluate the effect of 2 different CAD/CAM systems (Cerec inLab, Kavo Everest) on the marginal fit of 2 types of zirconia-based and lithium disilicate crowns. MATERIAL AND METHODS: Forty zirconia-based and lithium disilicate crowns, 20 each, were fabricated with the Cerec inLab and Everest CAD/CAM systems on a specially designed stainless steel die to ensure the standardization of specimen shape and dimensions. The vertical marginal fit for all tested crowns was evaluated by using a digital microscope at ×100 magnification, and the data were tabulated and statistically analyzed with 2-way ANOVA, followed by the Tukey honestly significant difference (HSD) test with a confidence level of .05 to determine the mean differences. RESULTS: The results showed that the CAD/CAM technique, ceramic type, and their interaction had a statistically significant effect on the mean marginal fit of both ceramic types tested. CONCLUSIONS: Better marginal fit values were exhibited by the Everest CAD/CAM technique for both ceramic types tested.
Assuntos
Desenho Assistido por Computador/normas , Coroas/normas , Adaptação Marginal Dentária , Porcelana Dentária/química , Planejamento de Prótese Dentária/normas , Humanos , Microscopia/instrumentação , Modelos Dentários , Aço Inoxidável/química , Propriedades de Superfície , Preparo Prostodôntico do Dente , Ítrio/química , Zircônio/químicaRESUMO
In recent years the frequency of and esthetic demand for implant restorations in the esthetic zone has increased. Recent literature has revealed numerous consistent trends which may aid the clinician in achieving predictable esthetics. Maintaining generous facial bone by judicious placement as well as by using implants with diameters of less than 4 mm appears to be beneficial. Avoiding adjacent implants in the esthetic zone while maintaining an implant to tooth distance of between 2 mm and 4 mm seems to aid in bone and soft tissue maintenance. Abutment connections in which the abutment is narrower than the implant offer distinct advantages, most notably increased bone heights. Also, provisional restoration, especially early in treatment provides long-term esthetic benefits.
Assuntos
Processo Alveolar/anatomia & histologia , Implantes Dentários , Estética Dentária , Periodonto/anatomia & histologia , Projeto do Implante Dentário-Pivô , Implantação Dentária Endóssea/métodos , Planejamento de Prótese Dentária , Prótese Dentária Fixada por Implante , Restauração Dentária Temporária , HumanosRESUMO
STATEMENT OF PROBLEM: With growing demand for high esthetic standards, dentists must understand patient perception and incorporate their preferences into treatment. However, little is known about how cultural and ethnic differences influence esthetic perception. PURPOSE: The purpose of this study was to determine whether differences in ethnic background, including the possibility of assimilation, affected a layperson's perception of esthetic and smile characteristics. MATERIAL AND METHODS: A survey was developed containing images that were digitally manipulated into a series of barely perceptible steps, changing 1 smile parameter to form a strip of images that displayed that parameter over a wide range. Data were collected with a customized program which randomly displayed a single image and allowed the subject to use the mouse to adjust an on-screen slider according to displayed instructions, that is, "Please move the slider to select the image you find to be most ideal"; or "Please move the slider to select the first image that you find unattractive." A convenience sample (n=288) comprised of U.S. whites, U.S. Asian Indians, and Indians living in India was surveyed. This sample provided a power of .86 to detect a difference of ±1.5 mm. Subjects evaluated images showing the smile arc, buccal corridor, gingival display, vertical overlap, lateral incisal step, maxillary midline to midface, and maxillary to mandibular midline. Rater reliability was assessed with the Fleiss-Cohen weighted Kappa (Kw) statistic and corresponding 95% confidence interval after each question was repeated in a random sequence. Choice differences due to ethnicity were assessed with a multiple randomization test and the adjusted P value with the step-down Bonferrroni method of Holm (α=.05). RESULTS: The Kw for the 17 variables in all 3 groups ranged from 0.11 for ideal vertical overlap to 0.64 for ideal buccal corridor space. Overall reliability was fair to moderate. Differences attributed to ethnicity were demonstrated between the Asian Indians and U.S. whites. Differences attributed to assimilation were demonstrated between U.S. Asian Indians and Asian Indians. Differences between U.S. Asian Indians and U.S. whites can be instructive and demonstrate the relative power of ethnicity and assimilation. A difference between these groups shows the power of ethnicity and no difference between these groups shows the power of assimilation. The ratings of the Asian Indians and the U.S. whites showed a clinically significant difference for Ideal Buccal Corridor and Maximum Smile Arc. There were no significant differences between the U.S. Asian Indians and Asian Indians. There were clinically significant differences between the U.S. Asian Indians and U.S. whites only for Ideal Buccal Corridor. CONCLUSIONS: Ethnicity had a significant effect on the esthetic choices for Buccal Corridor and Smile Arc. There is no conclusive evidence for assimilation.
Assuntos
Aculturação , Comparação Transcultural , Estética Dentária/psicologia , Sorriso , Adulto , Idoso , Análise de Variância , Feminino , Humanos , Índia/etnologia , Masculino , Pessoa de Meia-Idade , Sulco Nasogeniano , Variações Dependentes do Observador , Fotografia Dentária , Sorriso/psicologia , Estatísticas não Paramétricas , População Branca , Adulto JovemRESUMO
STATEMENT OF PROBLEM: Ceramic laminate veneers are generally fabricated with varying thicknesses ranging from 0.3 to 1 mm, depending on the need to mask discolored teeth or slightly correct the contour of malpositioned teeth. Clinical color reproduction poses a challenge because of color interaction with the underlying substrate, whether tooth structure or esthetic restorative material. PURPOSE: The purpose of this in vitro investigation was to measure the effect of color change resulting from applying 2 shades of ceramic material, translucent (T1) and opaque (O2), to 2 shades of composite resin substrate material, light (A3) and dark (C4), on the overall color of ceramic laminates. MATERIAL AND METHODS: Forty disks were fabricated. Twenty disks (15 × 0.5 mm) were cut from pressed ceramic, 10 disks for each shade (translucent and opaque). Additionally, 20 disks (15 × 4.0 mm) were fabricated from light-polymerized composite resin material, 10 disks for each shade (light and dark). The ceramic disks were bonded to the composite resin disks with clear resin cement. The specimen combinations were divided into 4 groups (n=5). Color measurements were done with a colorimeter (Minolta Chroma Meter CR-200b) configured with diffuse illumination/0-degree viewing geometry. Mean CIE lightness (L*), chroma (C*(ab)), and hue angle (h(ab)) values were obtained. A 2-way analysis of variance (ANOVA) was used to compare the means and standard deviations between the different color combinations (α=.05), followed by Tukey's HSD post hoc test for significant interactions. RESULTS: The 2-way ANOVA showed significant differences (P<.001) in L*, C*(ab), and h(ab) for a change in the composite resin substrate, regardless of the ceramic material shade. There was significant color change from dark to light substrate (P=.044). The mean h(ab) (SD) of dark substrate/opaque veneer was 89.62 (1.5), while the mean h(ab) of light substrate/translucent veneer was 81.23 (1.7). CONCLUSIONS: Within the limitations of this study, the selected color of a 0.5 mm ceramic laminate veneer was significantly affected by the change in color of the supporting substrate.
Assuntos
Resinas Compostas , Porcelana Dentária , Planejamento de Prótese Dentária , Facetas Dentárias , Pigmentação em Prótese/métodos , Cor , ColorimetriaRESUMO
PURPOSE: Unresolved controversy exists concerning the optimum restorative material to reinforce the thin-walled roots of endodontically treated teeth to improve their fracture resistance under occlusal load. This study evaluated the effectiveness of irrigant, dowel type, and root-reinforcing material on the fracture resistance of thin-walled endodontically treated teeth. MATERIALS AND METHODS: The root canals of 140 maxillary central incisors were enlarged and equally divided into seven groups according to the canal irrigant: no irrigant (control), 5% hydrogen peroxide, 5% sodium hypochlorite, a combination of 5% hydrogen peroxide and sodium hypochlorite, 15% ethylenediaminotetraacetic acid (EDTA), 10% lactic acid, or 20% lactic acid. Within each group, root canals were lined with composite resin (PermaFlo) or glass ionomer cement (Fuji II LC). A light-transmitting plastic dowel (Luminex) was used to create space for a quartz fiber-reinforced dowel (Aestheti Post) or a titanium alloy dowel (ParaPost XH) and to cure the restorative materials. Following dowel cementation and restoration of the roots with composite core, the teeth were submitted to fracture resistance testing, and data were analyzed with 3-way ANOVA followed by Ryan-Einot-Gabriel-Welsch Multiple Range Test (α= 0.05). RESULTS: Fracture resistance values were significantly different among irrigants, restorative materials, and their interaction (p < 0.001); however, the dowel type was not significantly different (p= 0.51). CONCLUSIONS: Thin-walled roots that had the smear layer removed with lactic acid and that were then lined with composite resin had a higher fracture resistance.
Assuntos
Resinas Compostas/química , Materiais Dentários/química , Cavidade Pulpar/fisiopatologia , Cimentos de Ionômeros de Vidro/química , Técnica para Retentor Intrarradicular/instrumentação , Irrigantes do Canal Radicular/uso terapêutico , Preparo de Canal Radicular/métodos , Fraturas dos Dentes/fisiopatologia , Dente não Vital/fisiopatologia , Fenômenos Biomecânicos , Ligas Dentárias/química , Análise do Estresse Dentário/instrumentação , Dentina/fisiopatologia , Ácido Edético/uso terapêutico , Guta-Percha/uso terapêutico , Humanos , Peróxido de Hidrogênio/uso terapêutico , Incisivo/fisiopatologia , Ácido Láctico/uso terapêutico , Teste de Materiais , Microscopia Eletrônica de Varredura , Quartzo/química , Resinas Sintéticas/química , Materiais Restauradores do Canal Radicular/uso terapêutico , Preparo de Canal Radicular/instrumentação , Hipoclorito de Sódio/uso terapêutico , Estresse Mecânico , Titânio/químicaRESUMO
Thin-walled root canals always present a challenge to dentists to select a restorative treatment that does not further weaken the thin tooth structure. The prognosis of dowel and core restorations can be unpredictable. This clinical report describes the treatment of a patient with extensive caries extending into the root canal of an endodontically treated maxillary central incisor. The use of a flowable composite resin in combination with a quartz fiber reinforced post is described, resulting in the rehabilitation of a structurally compromised root canal with satisfactory esthetic and functional outcomes.
Assuntos
Resinas Compostas/química , Materiais Dentários/química , Cavidade Pulpar/patologia , Estética Dentária , Incisivo/patologia , Técnica para Retentor Intrarradicular/instrumentação , Dente não Vital/reabilitação , Adulto , Colagem Dentária , Cárie Dentária/terapia , Cimentos Dentários/química , Humanos , Masculino , Metacrilatos/química , Quartzo/química , Cimentos de Resina/química , Tratamento do Canal Radicular , Resultado do TratamentoRESUMO
PURPOSE: To identify how different treatments of the root dentin surface affect the microscopic appearance of the resin composite/glass-ionomer cement-to-dentin interface. METHODS: The root canals of 70 extracted human single-rooted teeth were enlarged to reduce dentin wall thicknesses to 0.5 mm. The roots were randomly divided into seven test groups (n=10) according to the canal irrigant used: no irrigant (control), 5% hydrogen peroxide, 5% sodium hypochlorite, a combination of 5% hydrogen peroxide and sodium hypochlorite, 15% ethylenediaminetetraacetic acid (EDTA), 10% lactic acid, or 20% lactic acid. To simulate thin-walled roots, within each group, crowns were sectioned and the entire surface of each root canal space was enlarged with Profile instrument. Half of treated root canals (n=5) were filled with resin composite (PermaFlo) and the other half were filled with glass-ionomer cement (Fuji II LC). A light-transmitting plastic post (Luminex) was used to create space for a fiber-reinforced post and to ensure polymerization of the restorative material. Specimens were critical-point dried and freeze fractured for scanning electron microscope analysis. Three sites along the root were evaluated (cervical, middle, and apical). RESULTS: Scanning electron micrographs showed no differences in the morphology of the resin tags at the cervical, middle or apical levels with any of the irrigants or the restorative materials used. Also, no difference in surface topography was found within individual groups. A resin-dentin interdiffusion zone and resin tags developed after application of resin composite with lactic acid solutions and EDTA but not with the glass-ionomer cement.
Assuntos
Resinas Compostas , Colagem Dentária , Cimentos de Ionômeros de Vidro , Técnica para Retentor Intrarradicular/instrumentação , Irrigantes do Canal Radicular , Cavidade Pulpar/ultraestrutura , Dentina/ultraestrutura , Permeabilidade da Dentina , Humanos , Microscopia Eletrônica de Varredura , Resinas Sintéticas , Propriedades de SuperfícieRESUMO
INTRODUCTION: Although attractiveness and acceptability of orthodontic appliances have been rated by adults for themselves and for adolescents, children and adolescents have not provided any substantial data. The objective of this study was to evaluate preferences and acceptability of orthodontic appliances in children and adolescents. METHODS: Images of orthodontic appliances previously captured and standardized were selected and incorporated into a computer-based survey. Additional images of shaped brackets and colored elastomeric ties, as well as discolored clear elastomeric ties, were captured and incorporated onto existing survey images with Photoshop (Adobe, San Jose, Calif). The survey displayed 12 orthodontic appliance variations to 139 children in 3 age groups: 9 to 11 years (n = 45), 12 to 14 years (n = 49), and 15 to 17 years (n = 45). The subjects rated each image for attractiveness and acceptability. All images were displayed and rated twice to assess rater reliability. RESULTS: Overall reliability ratings were r = 0.74 for attractiveness and k = 0.66 for acceptability. There were significant differences in bracket attractiveness and acceptability in each age group. The highest-rated appliances were clear aligners, twin brackets with colored ties, and shaped brackets with and without colored ties. Colored elastomeric ties improved attractiveness significantly over brackets without colored ties for children in the 12-to-14 year group. There was a tendency for older subjects to rate clear orthodontic appliances higher than did younger subjects. Ceramic brackets with discolored ties tended to be rated lower than ceramic brackets with new ties and scored lowest in acceptability and attractiveness in all age groups. Girls rated shaped brackets significantly higher than did boys. CONCLUSIONS: Children's preferences for orthodontic appliances differ by age and sex. Child and adolescent preferences differ from adult preferences.
Assuntos
Aparelhos Ortodônticos , Preferência do Paciente , Adolescente , Fatores Etários , Cerâmica , Criança , Cor , Gráficos por Computador , Ligas Dentárias , Materiais Dentários , Elastômeros , Estética Dentária , Feminino , Humanos , Masculino , Desenho de Aparelho Ortodôntico , Braquetes Ortodônticos , Fios Ortodônticos , Aceitação pelo Paciente de Cuidados de Saúde , Satisfação do Paciente , Fotografia Dentária , Aço InoxidávelRESUMO
PURPOSE: Presurgical planning is essential to achieve esthetic and functional implants. The goal of this clinical study was to determine the angular and linear deviations at the implant neck and apex between planned and placed implants using stereolithographic (SLA) surgical guides. PATIENTS AND METHODS: A total of 110 implants were placed using SLA surgical guides generated from computed tomography (CT). All patients used the radiographic templates during CT scanning. After obtaining 3-dimensional CT scans, each implant insertion was simulated on the CT images. SLA surgical guides using a rapid prototyping method including a laser beam were used during implant insertion. A new CT scan was made for each patient after implant insertion. Special software was used to match images of the planned and placed implants, and their positions and axes were compared. RESULTS: The mean angular deviation of all placed implants was 4.1 degrees+/-2.3 degrees, whereas mean linear deviation was 1.11+/-0.7 mm at the implant neck and 1.41+/-0.9 mm at the implant apex compared with the planned implants. The angular deviations of the placed implants compared with the planned implants were 2.91 degrees+/-1.3 degrees, 4.63 degrees+/-2.6 degrees, and 4.51 degrees+/-2.1 degrees for the tooth-supported, bone-supported, and mucosa-supported SLA surgical guides, respectively. CONCLUSION: The results of this study suggested that stereolithographic surgical guides using CT data may be reliable in implant placement, and tooth-supported SLA surgical guides were more accurate than bone- or mucosa-supported SLA surgical guides.
Assuntos
Implantação Dentária Endóssea/métodos , Arcada Edêntula/diagnóstico por imagem , Modelos Anatômicos , Cirurgia Assistida por Computador , Tomografia Computadorizada por Raios X/métodos , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional/métodos , Masculino , Pessoa de Meia-Idade , Modelos Dentários , Planejamento de Assistência ao Paciente , Fotografia Dentária , Estatísticas não ParamétricasRESUMO
STATEMENT OF PROBLEM: Clinical studies have shown that lack of retention is one of the major causes of fixed dental prosthesis failure. PURPOSE: The purpose of this study was to determine the relationship between the convergence angle of a complete metal crown tooth preparation and the recementation strength for restorations cemented with conventional and adhesive cements. MATERIAL AND METHODS: One hundred twenty artificial crowns were cast for standardized complete metal crown tooth preparations accomplished with the use of a milling machine on extracted human teeth. Three different tapers, 5, 12, and 25 degrees, were used (n=40). The crowns in each group were subdivided into 4 subgroups (n=10) according to the luting cement: zinc phosphate cement (Fleck's), glass ionomer cement (Ketac-Cem), and adhesive resin cements (Panavia 21 and C&B-Metabond). Retention was evaluated by measuring the tensile force required to dislodge the crowns from the tooth preparations in a universal testing machine. Subsequently, the tooth preparations were scraped clean and polished with prophylaxis paste, and the intaglio surfaces of the artificial crowns were ultrasonically cleaned and airborne-particle abraded with 50-mum aluminum oxide powder prior to recementation. The data were analyzed with 3-way repeated-measures ANOVA and Tukey's HSD test (alpha=.05). RESULTS: Analysis of measurements disclosed a significant difference for taper and luting cement (P<.001); however, their interaction was not significant. Also, there was a statistically significant difference between the retention of the first cementation and the second cementation (P<.001). However, the interaction was not significant with taper or cement. Regardless of the taper used, Panavia 21 cement exhibited the highest mean initial retention, but the difference was not significantly different from the recementation retentive strength. CONCLUSIONS: Tooth preparation taper and type of luting cement had a direct effect on the recementation strength of complete metal crowns.