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1.
J Prosthodont Res ; 65(4): 554-558, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34193745

RESUMO

Purpose Implant-assisted removable partial dentures (IARPDs) with short implants improve the oral functions of removable partial dentures (RPDs). This study aimed to compare the patient-reported outcomes of RPDs and IARPDs with short implants retained by magnetic attachments.Methods We recruited 30 participants with mandibular Kennedy Class I or II and distal extension defects of three or more teeth. RPDs, IARPDs with a healing cap, and IARPDs with a magnetic attachment were evaluated across stages using patient-reported outcomes. All participants completed questionnaires (oral health-related quality of life [OHRQoL], patient general satisfaction, and patient's denture assessment [PDA]) at each stage. The OHRQoL was evaluated using the Oral Health Impact Profile-J 54 (OHIP-J 54) score. The general patient satisfaction was evaluated using a 100 mm visual analog scale. The Wilcoxon signed-rank test and Bonferroni correction were used to evaluate differences between the groups (α=0.05).Results The OHRQoL of IARPDs was significantly higher than that of RPDs. IARPDs with a magnetic attachment had significantly better patient general satisfaction and PDA than IARPDs with a healing cap.Conclusions The OHRQoL, patient general satisfaction, and PDA were improved by IARPD with a short implant using a magnetic attachment.


Assuntos
Prótese Parcial Removível , Prótese Dentária Fixada por Implante , Humanos , Fenômenos Magnéticos , Medidas de Resultados Relatados pelo Paciente , Estudos Prospectivos , Qualidade de Vida
2.
Int J Implant Dent ; 7(1): 57, 2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34184165

RESUMO

BACKGROUND: The appropriate loading protocol to improve masticatory performance (MP) is still unclear in elderly patients and two-implant overdentures (2-IODs) wearers. This study aimed to compare the long-term MP and maximum occlusal force of immediate loading (IL) and conventional loading (CL) of 2-IODs retained by magnetic attachments. Nineteen edentulous patients were randomly assigned to either an IL (n=10) or CL group (n = 9). In the IL group, the implant was loaded on the same day as insertion, whereas it was loaded 3 months after insertion in the CL group. Magnetic attachments were used to retain all overdentures to the implants. MP, measured by a piece of color-changeable chewing gum and a gummy jelly test, and maximum occlusal force, measured using an occlusal force measuring device, were assessed in both groups at baseline and at 3-, 4-, and 5-year follow-ups. RESULTS: No significant differences were observed in the MP and the maximum occlusal force between the IL and CL groups at any time point. However, a significantly higher MP was observed at the 3-year time point in the IL group (P = 0.036). The maximum occlusal force revealed a significant correlation with MP, both with the color-changeable chewing gum and gummy jelly at 5 years. CONCLUSION: After long-term observation, no significant differences in MP and maximum occlusal force were observed between the IL and CL groups. However, compared to pre-implant insertion of the complete denture, the MP in the IL group significantly improved at 3 years. Furthermore, the maximum occlusal force was significantly correlated with MP at 5 years. TRIAL REGISTRATION: UMIN, UMIN000009889 . Registered on 28 January 2013.

3.
Polymers (Basel) ; 13(11)2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-34073564

RESUMO

In this study, the physical properties of a custom block manufactured using a self-polymerizing resin (Custom-block), the commercially available CAD/CAM PMMA disk (PMMA-disk), and a heat-polymerizing resin (Conventional PMMA) were evaluated via three different tests. The Custom-block was polymerized by pouring the self-polymerizing resin into a special tray, and Conventional PMMA was polymerized with a heat-curing method, according to the manufacturer's recommended procedure. The specimens of each group were subjected to three-point bending, water sorption and solubility, and staining tests. The results showed that the materials met the requirements of the ISO standards in all tests, except for the staining tests. The highest flexural strength was exhibited by the PMMA-disk, followed by the Custom-block and the Conventional PMMA, and a significant difference was observed in the flexural strengths of all the materials (p < 0.001). The Custom-block showed a significantly higher flexural modulus and water solubility. The water sorption and discoloration of the Custom-block were significantly higher than those of the PMMA-disk, but not significantly different from those of the Conventional PMMA. In conclusion, the mechanical properties of the three materials differed depending on the manufacturing method, which considerably affected their flexural strength, flexural modulus, water sorption and solubility, and discoloration.

4.
J Prosthodont Res ; 65(4): 535-540, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33980785

RESUMO

Purpose The aim of this study was to evaluate patients' economic preferences for two different tooth replacement strategies for the edentulous mandible namely conventional complete dentures (CCDs) and implant overdentures supported by two implants (IODs), using a willingness-to-pay (WTP) analysis.Methods Twenty-six elderly patients who had been rehabilitated with either a mandibular CCD or IOD were invited to participate in this study. All participants were provided with the details of the two treatment protocols, including advantages, disadvantages, and treatment costs. The patients were then asked to indicate their maximum WTP values for each protocol using a payment card method for contingency evaluation.Results Fifteen patients with mandibular CCD (CCD-Group) and 12 patients with IOD (IOD-Group) participated in the study. Overall, the median and maximum WTP values recorded for IOD therapy were significantly higher than those for CCD therapy (p<0.05). Both treatment groups recorded maximum WTP values for CCD therapy, which exceeded the market cost (¥30,000 [US$280]), CCD-Group: ¥50,000 (interquartile range [IQR]: 40,000 - 65,000), and IOD-Group: ¥45,000 (IQR: 30,000-85,000)]. However, both groups registered a median and maximum WTP values for IOD therapy lower than the market cost (¥780,000 [US$7,300]), (CCD-Group: ¥500,000 [IQR: 300,000 - 750,000], IOD-Group: ¥700,000 [IQR: 500,000-800,000]).Conclusion The maximum WTP values recorded for IOD therapy were significantly higher than CCD therapy in both treatment groups. While patients were willing to pay more than the current market costs for CCDs, they were not willing to meet the market value for IODs.


Assuntos
Mandíbula , Preferência do Paciente , Idoso , Prótese Total , Revestimento de Dentadura , Humanos
5.
J Nutr Sci Vitaminol (Tokyo) ; 67(1): 48-56, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33642464

RESUMO

Dietary habits of middle-aged and elderly individuals affected by periodontal disease (PD) differ from those who are unaffected by it, according to previous reports. However, in young adults, there are only a few reports that show a correlation between nutrient/food intake and PD. Moreover, no report till date has assessed the correlation between dietary habits and PD using a self-administered diet history questionnaire (DHQ). Therefore, we assessed this correlation using a DHQ in young adult women who are likely to develop PD. The participants were enrolled from 2 universities and included 120 female college students a mean age of 20.4 y. The participants were assessed for the presence of PD according to the community periodontal index and were divided into two groups, the PD group and the non-PD group. Their dietary habits were investigated using a DHQ and the level of difficulty in chewing food was assessed. The PD group had a significantly lower nutrient intake of minerals, fat-soluble vitamins, water-soluble vitamins, and dietary fiber than the non-PD group. In terms of food groups, the PD group consumed significantly lesser amounts of green and yellow vegetables (GYV) than the non-PD group. Multivariate analysis revealed that the PD group had significantly lower intakes of vitamin E and GYV than the non-PD group. The PD group consumed significantly lesser amounts of hard foods than the non-PD group. In conclusion, young adult women who were evaluated for PD by a screening test had a significantly lower nutrient/food intake than those without a PD.


Assuntos
Dieta , Doenças Periodontais , Idoso , Ingestão de Energia , Comportamento Alimentar , Feminino , Humanos , Pessoa de Meia-Idade , Doenças Periodontais/etiologia , Inquéritos e Questionários , Vitaminas , Adulto Jovem
6.
J Prosthet Dent ; 2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33773771

RESUMO

STATEMENT OF PROBLEM: Insufficient information is available regarding the trueness and precision of artificial teeth in computer-aided design and computer-aided manufacturing (CAD-CAM) milled complete dentures fabricated from custom disks, including prefabricated teeth. PURPOSE: The purpose of this in vitro study was to determine the trueness and precision of the position of the artificial teeth arranged in CAD-CAM milled complete dentures manufactured by using a custom disk method and to compare the trueness and precision of different tooth types and the occlusal surface and entire surface of the teeth. MATERIAL AND METHODS: The milling data were designed by using a CAD software program. Four types of artificial teeth (maxillary-left central incisor, mandibular-left central incisor, maxillary-left first premolar, and maxillary-left first molar) were arranged concentrically in the disk with 3 corresponding teeth per disk. Five custom disks were milled based on the milling data. The sample size for maxillary-left central incisor, mandibular-left central incisor, maxillary-left first premolar, and maxillary-left first molar was 15. The standard tessellation language data were obtained by scanning the milled disks with cone beam computed tomography. The obtained data were superimposed by using a CAD software program to assess the trueness and precision of the tooth positions. For the occlusal surface, the data were superimposed after trimming to assess the trueness and precision of the tooth position with respect to the entire tooth surface. After data superimposition, the deviation was analyzed by using a 3-dimensional analysis software program to obtain the mean absolute error values and color maps. The data were analyzed by using 2-way ANOVA and the Games-Howell post hoc test (α=.05). RESULTS: Significant differences were found in the mean absolute error values of the position trueness of the entire surface between the different teeth, except for maxillary-left first premolar and maxillary-left first molar (P<.05). Moreover, significant differences in the mean absolute error values of the precision for the entire surface were observed between mandibular-left central incisor and maxillary-left first premolar, as well as between mandibular-left central incisor and maxillary-left first molar (P<.05). The mean absolute error values of the position trueness of the occlusal surface were significantly smaller than those for the entire tooth surface for mandibular-left central incisor, maxillary-left first premolar, and maxillary-left first molar (P<.05). Finally, the mean absolute error values of the position precision of the occlusal surface were significantly smaller than those for the entire tooth surface for mandibular-left central incisor and maxillary-left first premolar (P<.05). CONCLUSIONS: The trueness and precision of the posterior teeth were higher than that of anterior teeth. The trueness of the movement of the artificial teeth during the manufacturing of dentures by using the custom disk method was found to be within a clinically acceptable range.

7.
J Prosthet Dent ; 2021 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-33583615

RESUMO

STATEMENT OF PROBLEM: Stereolithography (SLA) additive manufacturing (AM) technologies have become popular for the fabrication of complete dentures; however, the trueness and precision of the dentures under different postpolymerization conditions remain unclear. PURPOSE: The purpose of this in vitro study was to investigate the effect of different postpolymerization times and temperatures on the trueness and precision of SLA dentures. MATERIAL AND METHODS: Specimens simulating maxillary complete dentures were fabricated by SLA 3D printing. They were polymerized for 15 minutes or 30 minutes at different temperatures (40 °C, 60 °C, and 80 °C). The intaglio surface trueness of the specimens was evaluated by superimposing the postpolymerization standard tessellation language (STL) file on the original STL file for each specimen via a best-fit method (n=10). The precision was measured across specimens by superimposing the postpolymerization STL file from each specimen group and using the combination formula (n=45). Subsequently, root-mean-square estimates (RMSEs) and color map data were obtained, and a normality test was conducted on the obtained data. The results indicated that the distributions were not normal; therefore, nonparametric Kruskal-Wallis and Mann-Whitney tests were used to analyze the data (α=.05). RESULTS: For trueness, the lowest RMSE corresponded to the postpolymerization time of 30 minutes and a temperature of 40 °C. This result was significantly different from specimens those of the 15-minute and 60 °C, 15-minute and 80 °C, and 30-minute and 80 °C specimens (P<.001). For precision, the median of the lowest RMSE corresponded to the 30-minute and 40 °C specimens. This median value was significantly different from those of other specimens (P<.001). The findings indicate that the postpolymerization condition of 30 minutes and 40 °C affords the highest trueness and precision and the most favorable intaglio surface adaptation of the denture. CONCLUSIONS: The postpolymerization conditions influenced the RMSE values of the trueness and precision of a clear photopolymer resin. The RMSE and color map data associated with the 30-minute and 40 °C condition corresponded to the greatest trueness and precision of all the SLA denture specimens considered.

8.
BMC Oral Health ; 21(1): 4, 2021 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-33407371

RESUMO

BACKGROUND: Metabolic syndrome (MetS), caused by the accumulation of visceral fat, is considered a major cause of cardiovascular disease. This randomized controlled trial aimed to clarify the effect of dental intervention, including prosthodontics and/or periodontal treatment, combined with dietary and exercise guidance on MetS. METHODS: In total, 112 patients who met the Japanese waist circumference criteria of MetS were recruited. The intervention group (ITG) received dental intervention along with dietary and exercise guidance, while the control group (CTG) received dietary and exercise guidance alone. Three outcome measurements were obtained before intervention (BL), 1 month after intervention (1M), and 3 months after intervention (3M). RESULTS: Body water rate (p = 0.043) was significantly higher in ITG than in CTG at 1M. Simultaneously, fasting blood sugar level (p = 0.098) tended to be lower in ITG than in CTG. Lean mass (p = 0.037) and muscle mass (p = 0.035) were significantly higher and body weight (p = 0.044) significantly lower in ITG than in CTG at 3M. Body mass index (p = 0.052) tended to be lower in ITG than in CTG. CONCLUSIONS: Dental intervention combined with lifestyle guidance may improve anthropometric status and reduce the risk of MetS. TRIAL REGISTRATION: University Hospital Medical Information Network Center Unique UMIN000022753. https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000026176 .


Assuntos
Síndrome Metabólica , Índice de Massa Corporal , Dieta , Humanos , Estilo de Vida , Síndrome Metabólica/terapia , Circunferência da Cintura
9.
J Prosthet Dent ; 126(2): 150-154, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32800576

RESUMO

A straightforward technique is presented for an interim or short-term definitive esthetic replacement of missing anterior teeth requiring no tooth preparation. Composite resins are injected into transparent silicone indices fabricated from 3-dimensional-printed casts of a digital waxing. The dentin core is formed of a durable short fiber-reinforced injectable composite resin and veneered with an enamel-shade composite resin for enhanced esthetics. Besides being noninvasive, this technique is more straightforward than traditional options, reducing chair time while providing an accurate outcome.


Assuntos
Resinas Compostas , Prótese Dentária , Estética Dentária , Humanos , Incisivo , Fluxo de Trabalho
10.
J Prosthet Dent ; 125(4): 695-702, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32416982

RESUMO

STATEMENT OF PROBLEM: The appropriate postpolymerization of stereolithography (SLA) resins with the least effect on dimensional accuracy and with optimal polymerization is unclear. PURPOSE: The purpose of this in vitro study was to investigate the dimensional accuracy and degree of polymerization of a photopolymer resin for SLA with different postpolymerizing times and temperatures. MATERIAL AND METHODS: Sixty 1.5-mm-thick specimens were made from clear photopolymer resin with a 3D printer to simulate a maxillary complete denture. They were postpolymerized for different periods (15 and 30 minutes) at 3 different temperatures (40 °C, 60 °C, and 80 °C). Both prepolymerization and postpolymerization gap sizes for each specimen were measured at 5 different locations under a stereomicroscope. The tissue surface was scanned before and after polymerization, and the images were superimposed. The deviation was analyzed by using computer-aided design (CAD) software; root mean square estimates (RMSE) and color map data were obtained. Fourier transform infrared spectrometry was used to determine the degree of conversion (DC) of all specimens. The Kruskal-Wallis and Mann-Whitney tests were used to calculate the difference value of the gap sizes (α=.05). One-way ANOVA and the Tukey test were used for RMSE and DC (α=.05). RESULTS: The smallest average change in gap sizes was found at 15 minutes and 40 °C, and the largest change at 30 minutes and 80 °C. The lowest RMSE was obtained at 30 minutes and 40 °C (P<.05). On the color map, a uniform deposited layer was created at 15 minutes and 40 °C and 30 minutes and 40 °C. The highest DC was found at 30 minutes and 60 °C, which differed significantly from 15 minutes and 40 °C (P<.05). The lowest degree of polymerization was found at 30 minutes and 40 °C. CONCLUSIONS: The polymerizing temperature exerted a greater effect than polymerizing time, with lower temperatures leading to improved fit and tissue surface accuracy. The recommended parameters for SLA polymerization are 15 minutes and 40 °C. These conditions offered high dimensional accuracy, favorable surface tissue adaptation, and satisfactory DC.


Assuntos
Desenho Assistido por Computador , Estereolitografia , Teste de Materiais , Polimerização , Temperatura
11.
J Prosthet Dent ; 2020 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-33190864

RESUMO

A digital complete denture was manufactured from a disk customized for each patient. The custom disk was made of resin and contained prefabricated artificial teeth. Both the denture base and the artificial teeth in the custom disk were milled in this technique, resulting in dentures with a high bond strength between the artificial teeth and denture base, excellent esthetics because of the prefabricated artificial teeth, and accurate occlusion because of the custom occlusal surface.

12.
J Oral Sci ; 62(4): 420-422, 2020 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-32908079

RESUMO

This study compared the mechanical properties and molecular distribution of a polymethyl methacrylate (PMMA) block (Dry) with specimens that were fabricated by a conventional method and cured in a wet environment (Control). Two specimen types were fabricated with heat-curing denture base resin. Dry specimens were polymerized at high pressure and in a dry system, while Control specimens were polymerized with a heat-curing method, in accordance with the manufacturer's recommended procedures. Specimens from each group were evaluated for three-point bending, water sorption and solubility, and color change, and by gel permeation chromatography (GPC). Mean values for the flexural strengths and moduli of the Dry specimens were significantly higher than those of the Control specimens (P > 0.05). Water sorption and discoloration values of the Dry group were significantly lower than those of the Control group. Mean weight-average molecular weights of the Dry group were higher than those of the Control group. As compared with the conventional method, the present method of fabricating PMMA blocks under high pressure yields superior mechanical properties for the denture base.


Assuntos
Desenho Assistido por Computador , Polimetil Metacrilato , Bases de Dentadura , Dentaduras , Teste de Materiais , Estresse Mecânico , Propriedades de Superfície
13.
J Mech Behav Biomed Mater ; 110: 103949, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32957241

RESUMO

Fabrication of complete dentures using a 3D printer is quicker and more economic than conventional methods. However, the photopolymer resins used in 3D printers has a lower flexural strength than heat-cured resin. Furthermore, photopolymer resins exhibit anisotropic properties depending on the printing direction, but no studies have evaluated their mechanical properties. The impact of stress distribution caused by changing the printing direction of the 3D printed denture has not been clarified. This study aimed to investigate the effect of different printing directions (0°, 45°, and 90°) of stereolithography (SLA) 3D printed dentures on stress distribution. Artificial mucosa was fabricated to fit a maxillary edentulous model, which was scanned to generate a standard tessellation language (STL) file. Subsequently, the upper denture was designed using computer-aided design (CAD) software, output as an STL file (master data), and set in three different printing directions (0°, 45°, and 90°). It was printed by the SLA 3D printer using photopolymer resin (n=6, in each printing direction). The stress distributions of the dentures were monitored using four rosette strain gauges, which were cemented to the midline of each denture as follows: above the labial frenum (A), at the incisive papilla (B), at the endpoint of the denture (D), and at the mid-point of B and D (C). A load was applied to the posterior region at a loading rate of 20 N/s from 0 N to 200 N using a universal testing machine. Changes in the applied load and strain at each point were recorded. The maximum principal strain (MPS) and the direction of the MPS (θ) were calculated. Each mean MPS was compared using Kruskal-Wallis and Steel-Dwass multiple comparison tests (p < 0.05). The stress distribution showed that the MPS for 45° printing was the lowest at each measurement point except for A under 200 N loading. The MPS at C for 0° was significantly different from that at C for 45° and 90°. The MPS at D in all the printing directions showed significant differences. The MPS at B for 45° was significantly different from that at B for 90°. The MPS at A in all printing directions showed no significant difference. Within the limitations of this study, differences in printing direction affected the stress distribution of SLA 3D printed dentures. The results showed that the stress distribution of the denture printed at 45° by the 3D printer system was the smallest compared with dentures printed at 0° and 90°. These results suggest that a printing direction of 45° is preferable when fabricating dentures using a 3D printer in clinical setting.


Assuntos
Impressão Tridimensional , Estereolitografia , Desenho Assistido por Computador , Dentaduras , Maxila
14.
Materials (Basel) ; 13(15)2020 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-32748815

RESUMO

This study evaluated the effects of the differences in the printing directions of stereolithography (SLA) three-dimensional (3D)-printed dentures on accuracy (trueness and precision). The maxillary denture was designed using computer-aided design (CAD) software with an STL file (master data) as the output. Three different printing directions (0°, 45°, and 90°) were used. Photopolymer resin was 3D-printed (n = 6/group). After scanning all dentures, the scanning data were saved/output as STL files (experimental data). For trueness, the experimental data were superimposed on the master data sets. For precision, the experimental data were selected from six dentures with three different printing directions and superimposed. The root mean square error (RMSE) and color map data were obtained using a deviation analysis. The averages of the RMSE values of trueness and precision at 0°, 45°, and 90° were statistically compared. The RMSE of trueness and precision were lowest at 45°, followed by 90°; the highest occurred at 0°. The RMSE of trueness and precision were significantly different among all printing directions (p < 0.05). The highest trueness and precision and the most favorable surface adaptation occurred when the printing direction was 45°; therefore, this may be the most effective direction for manufacturing SLA 3D-printed dentures.

15.
J Oral Sci ; 62(1): 98-102, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31996534

RESUMO

This study evaluated marginal bone loss and prosthetic complications associated with single implant-retained mandibular overdentures (1-IODs) with locator attachments. The 1-IOD was placed in the mandibular midline by using a conventional loading protocol in 22 patients with an edentulous mandible. Marginal bone loss at the start of loading and 12 months postoperatively was assessed by radiographic and crestal bone evaluation. The crestal bone was defined as the distance between the customized abutment shoulder and the top of the bone, as indicated by probing. In addition, implant stability quotient and prosthetic complications were recorded. The cumulative implant survival rate was 95.5%. Median implant stability quotient remained greater than 80, and median radiographic bone loss was 0.56 mm. Crestal measurement showed a median crestal bone loss of 0.16, 0.43, 0.39, and 0.52 mm on the buccal, right, lingual, and left sides, respectively. Both radiographic and crestal bone loss values significantly differed between the start of implant loading and 12 months postoperatively (except on the buccal and lingual sides; P < 0.05). The need to replace the nylon insert was the most common complication. Conventional loading of a 1-IOD with a locator attachment resulted in a high survival rate, good implant stability, and acceptable marginal bone loss.


Assuntos
Perda do Osso Alveolar , Implantes Dentários , Arcada Edêntula , Prótese Dentária Fixada por Implante , Revestimento de Dentadura , Humanos , Mandíbula
16.
Int J Oral Maxillofac Implants ; 34(6): 1434­1440, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31532825

RESUMO

PURPOSE: To treat mandibular edentulous patients by fitting immediately loaded two-implant overdentures via guided flapless surgery and evaluate their masticatory performance. MATERIALS AND METHODS: Nineteen patients who presented with edentulous mandibles (mean age: 69.8 years; range: 60 to 85 years) at the Dental Hospital, Tokyo Medical and Dental University, were enrolled in this study. A newly fabricated complete denture was used as a radiographic guide. Computer planning followed the design procedure, and surgical guides were fabricated for each patient. Flapless surgery was performed using this guide, and two implants were placed in the canine positions. On the day of surgery, a removable overdenture supported by two ball attachments was fitted. Masticatory function was evaluated on the basis of masticatory performance with a color-changeable chewing gum, maximum occlusal force with an occlusal force meter, and occlusal contact area with an occlusal diagnostic system. RESULTS: The masticatory performance significantly improved from 48 months after surgery. The maximum occlusal force significantly increased 24 months after surgery. The occlusal contact area significantly increased from 6 months after surgery. This prospective study indicated that maximum occlusal force and occlusal contact area significantly improved at a comparatively earlier period after implant surgery and were maintained for up to 5 years with the immediate loading of two-implant overdentures with stud attachments. However, masticatory performance took more time to improve than maximum occlusal force and occlusal contact area. CONCLUSION: According to this 5-year prospective study, masticatory performance, maximum occlusal force, and occlusal contact area showed significant improvement after 4 to 5 years, 2 years, and 6 months postsurgery, espectively.


Assuntos
Implantes Dentários , Revestimento de Dentadura , Idoso , Idoso de 80 Anos ou mais , Prótese Dentária Fixada por Implante , Humanos , Mandíbula , Pessoa de Meia-Idade , Estudos Prospectivos
17.
J Indian Prosthodont Soc ; 19(3): 272-275, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31462868

RESUMO

Three cases of mandibular implant overdentures (IODs) were measured for retention by a developed model. A nylon thread was tied through a hole at the midline of the IOD and seated it in the patient's mouth properly. Briefly, a facebow was set on the patient, with its arms firmly held by an assistant. The other end of the thread was tied into a loop, and the thread was inserted through a hole at the Camper's line of the facebow and hooked onto a portable force gauge. The thread was then pulled in parallel with the arms of the facebow by the force gauge until the prosthesis dislodged while the patient opened his mouth. Denture retention was measured five times, and the mean was calculated. Appropriate analysis for validity and reliability of the model was performed, and statistical results showed that it was valid and reliable for measuring the retention of removable mandibular prostheses.

18.
J Oral Rehabil ; 46(12): 1100-1106, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31228219

RESUMO

BACKGROUND: Dietary advice combined with prosthetic treatment could improve dietary intake earlier than prosthetic treatment only. This early improvement might signify early adaptation to new prostheses. Therefore, dietary advice might affect functional adaptation to new prostheses. OBJECTIVE: The aim was to clarify the influence of simple dietary advice on masticatory function of elderly individuals with new complete dentures. METHODS: A randomised controlled trial was performed on 59 edentulous elderly individuals who had received new complete dentures. Participants were randomly divided into an intervention group (received simple dietary advice: 15 men and 15 women, mean age: 74.8 ± 8.0 years) or a control group (received denture care advice: 15 men and 14 women, mean age: 78.6 ± 6.8 years). Masticatory function was assessed using colour-changeable chewing gum for mixing ability and test gummy jelly for shearing ability. Mixing and shearing ability were assessed at pre-treatment, and 3 and 6 months post-treatment. At each assessment time, mixing ability was compared using Student's t test and shearing ability using Mann-Whitney's U test. Within-group differences in mixing ability were analysed using repeated-measures one-way analysis of variance and those in shearing ability were analysed using Wilcoxon signed-rank test with Bonferroni correction. RESULTS: At each assessment time, there was no significant difference in mixing or shearing ability between groups. In the intervention group, mixing and shearing ability significantly increased at 3 and 6 months post-treatment. In the control group, mixing ability significantly increased at 6 months post-treatment. CONCLUSION: Simple dietary advice might lead to relatively early improvements in masticatory function.


Assuntos
Prótese Total , Boca Edêntula , Idoso , Idoso de 80 Anos ou mais , Goma de Mascar , Aconselhamento , Feminino , Alimentos , Humanos , Masculino , Mastigação
19.
J Prosthodont Res ; 63(4): 428-433, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30956160

RESUMO

PURPOSE: The study aimed to compare the mixing ability (MA), comminuting ability (CA), and maximum bite force (MBF) of single-implant overdentures (IODs) and clinically acceptable complete dentures (CDs) through a randomized crossover control trial. METHODS: New CDs were fabricated for 22 patients. One implant was inserted in the middle of the symphyseal region for each patient. The patients were randomly allocated into two groups: group IC received an IOD, whereas group CI received a CD, for 2 months; the treatments were interchanged for the next 2 months. The MA, CA, and MBF were evaluated with the old CDs, new CDs (at the end of CD treatment period), and IODs (at the end of IOD treatment period). RESULTS: The MA, CA, and MBF of the IODs were significantly higher than those of the old and new CDs (p < 0.01). New CDs only showed a significant improvement in MA (p < 0.05), while there were no significant differences in CA and MBF between the old and new CDs. CONCLUSIONS: Compared with the CD, IOD is more effective in restoring the MA, CA, and MBF of edentulous mandibles.


Assuntos
Força de Mordida , Prótese Dentária Fixada por Implante , Prótese Total , Revestimento de Dentadura , Retenção de Dentadura , Prótese Total Inferior , Humanos , Mandíbula , Mastigação , Satisfação do Paciente
20.
J Dent ; 83: 7-11, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30711603

RESUMO

OBJECTIVES: To compare the effect of conventional complete dentures fabricated using two different impression methods on masticatory performance and factors relating to masticatory performance in a randomized controlled trial. METHODS: A crossover randomized controlled trial was performed with edentulous patients requiring maxillomandibular complete dentures. Mandibular complete dentures were fabricated using two different methods. The conventional method (C) used a custom tray border molded with an impression compound and a silicone. The simplified method (S) used a stock tray and an alginate. Participants were randomly divided into the two groups. In the C-S group, the conventional method was used first, followed by the simplified method; the order was reversed in the SC group. Adjustments were performed four times. The wash out period was 1 month. Masticatory performance as assessed by the mixing of a color-changeable chewing gum (mixing ability). Maximum occlusal force, occlusal contact area, and perceived chewing ability were assessed for each group. RESULTS: Twenty-seven patients underwent randomization and 24 participants completed the trial. With regard to occlusal contact area, the conventional method showed significantly larger occlusal contact area than the simplified method. No significant differences were observed between the two methods regarding mixing ability, maximum occlusal force, and perceived chewing ability. CONCLUSIONS: This study showed that complete dentures fabricated with the conventional method had a significantly larger occlusal contact area than those made using the simplified method. CLINICAL SIGNIFICANCE: Complete dentures fabricated with the conventional method, comprising a preliminary impression using alginate in a stock tray followed by a final impression using silicone impression material in a border molded custom tray, resulted in fewer post-insertion adjustments than the simplified method, potentially contributing to earlier stability of new dentures.


Assuntos
Planejamento de Dentadura , Prótese Total , Boca Edêntula , Força de Mordida , Estudos Cross-Over , Humanos , Mastigação
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