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1.
Braz. j. oral sci ; 22: e237338, Jan.-Dec. 2023. ilus
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-1397295

RESUMO

Aim: Endocrown restorations are commonly used to rehabilitate endodontically treated posterior teeth and their use is well-founded in these cases. However, to date, there is little scientific evidence of their behavior in anterior teeth. The aim of this in vitro study was to evaluate the compressive strength of upper central incisors teeth, restored with glass-ceramic total crowns by the conventional anatomical core technique, and compare them to teeth restored with endocrowns with and without the presence of ferrule. Methods: Thirty teeth were randomly distributed into three groups: GE2 - endocrown group with 2 mm ferrule, GE0 - endocrown group without a ferrule, and GC - conventional crown with intraradicular post group. Crowns were cemented and teeth submitted to the 45o compression test until the fracture happened. Fractured specimens were analyzed to determine the fracture pattern. Descriptive analysis of the variables was performed and one-way analysis of variance was utilized to analyze the data for significant differences at p < 0.05. Results: The results of the control group (284.5 ± 201.05N) showed the highest fracture resistance value, followed by the 2mm group (274.54 ± 199.43N) and by the 0mm group (263.81 ± 80.05N). There was no statistically significant difference between all the groups (p = 0.964). Conclusions: The absence of a cervical enamel necklace favored a debonding of the pieces and endodontically treated anterior teeth could be restored with endocrown, which could be considered a conservative and viable treatment option


Assuntos
Desenho Assistido por Computador , Coroas , Endodontia , Resistência à Flexão
2.
Braz. j. oral sci ; 21: e225136, jan.-dez. 2022. ilus
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-1354771

RESUMO

Aim: To evaluate the influence of cobalt-chromium (Co-Cr) coping fabrication methods and ceramic application on the marginal and internal fit of metal-ceramic crowns. Methods: Co-Cr copings for metal-ceramic crowns were prepared by lost wax casting or CAD-CAM machining of sintered blocks. The fit was analyzed using the silicone replica technique at four assessment points: marginal gap (MG), axial wall (AW), axio-occlusal (AO) angle, and central occlusal (CO) wall. After the initial analysis, the copings were ceramic-veneered with the layering technique, and the fit was again determined. Data were statistically analyzed by paired and unpaired Student's-t test (α=0.05). Results: Marginal and internal fit before ceramic application according to the coping manufacturing method showed significant differences only at CO (p < 0.001), with milled copings (137.98±16.71 µm) showing higher gap values than cast copings (112.86±8.57 µm). For cast copings, there were significant differences at MG (before 109.13±8.79 µm; after 102.78±7.18 µm) and CO (before 112.86±8.57 µm; after 104.07±10.63 µm) when comparing the fit before and after ceramic firing. For milled copings, there was significant difference only at AO (before 116.39±9.64 µm; after 108.54±9.26 µm). Conclusion: This study demonstrated that the coping fabrication method influenced the internal fit. Ceramic firing maintained or improved the fit of the metal-ceramic crowns. The marginal discrepancy of all restorations, before and after ceramic firing, can be considered clinically acceptable


Assuntos
Cerâmica , Ligas Metalo-Cerâmicas , Adaptação Marginal Dentária , Coroas
3.
BMC Oral Health ; 22(1): 462, 2022 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-36324171

RESUMO

BACKGROUND: The healing period from crown lengthening procedures (CLPs) often delays the final crown delivery. This study aimed to explore the feasibility of a new approach expediting the delivery of the final crowns for teeth requiring CLPs. METHODS: Teeth requiring CLPs and single-crown restorations between the canine and the second molar were included. After the initial tooth preparation, a CLP was performed. In the experimental group, the final tooth preparation and final impression were made during the CLP; the final crown was then delivered at the suture-removal appointment. In the control group, the final impression was made 8 weeks after the CLP. The level of gingival margin (GM), pocket depth (PD), and crestal bone levels (CBLs) were compared between the two groups before CLPs (T0), at delivery of the crowns (T1), and at 12 months in function (T2). RESULTS: Twenty-one lithium-disilicate crowns were delivered to 20 subjects and followed up. The mean interval between the CLPs and the delivery of crowns was 2.5 weeks for the experimental group and 12 weeks for the control group. No significant differences were observed between the two groups in the level of GM, PD, and CBLs at each time point. No significant treatment difference in crestal bone loss was observed between the two groups at T2 (Experimental = -0.11 mm, Control = -0.03 mm; p = 0.67). CONCLUSION: Making the final tooth preparation and the final impression at the CLP significantly reduced the time between the CLP and the delivery of the final crown and showed comparable clinical outcomes.


Assuntos
Aumento da Coroa Clínica , Coroas , Projetos Piloto , Coroa do Dente/cirurgia , Dente Molar
4.
Head Face Med ; 18(1): 36, 2022 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-36411462

RESUMO

BACKGROUND: Tooth-colored onlays and partial crowns for posterior teeth have been used increasingly in clinics. However, whether onlays/partial crowns could perform as well as full crowns in the posterior region was still not evaluated thoroughly. METHODS: A literature search was conducted without language restrictions in Pubmed, Embase, Cochrane Central Register of Controlled Trial and Web of science until September 2021. RCTs, prospective and retrospective observational studies with a mean follow-up of 1 year were selected. Cochrane Collaboration's tool was adopted for quality assessment of the RCT. The quality of observational studies was evaluated following Newcastle-Ottawa scale. The random-effects and fixed-effects model were employed for meta-analysis. RESULTS: Four thousand two hundred fifty-seven articles were initially searched. Finally, one RCT was identified for quality assessment and five observational studies for qualitative synthesis and meta-analysis. The RCT was of unclear risk of bias while five observational studies were evaluated as low risk. The meta-analysis indicated no statistically significant difference in the survival between onlays/partial crowns and full crowns after 1 year (OR = 0.55, 95% CI: 0.02-18.08; I2 = 57.0%; P = 0.127) and 3 years (OR = 0.65, 95% CI: 0.20-2.17; I2 = 0.0%; P = 0.747). For the success, onlays/partial crowns performed as well as crowns (OR = 0.58, 95% CI: 0.20-1.72; I2 = 0.0%; P = 0.881) at 3 years. No significant difference of crown fracture existed between the two methods (RD = 0.00, 95% CI: - 0.03-0.03; I2 = 0.0%; P = 0.972). CONCLUSIONS: Tooth-colored onlays/partial crowns performed as excellently as full crowns in posterior region in a short-term period. The conclusions should be further consolidated by RCTs with long-term follow-up.


Assuntos
Coroas , Coroa do Dente , Humanos , Estudos Retrospectivos , Estudos Prospectivos
5.
Sci Rep ; 12(1): 19879, 2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36400914

RESUMO

Considering that the movement trajectory of roadheader cutting head directly affects the surface morphology characteristics of roadway forming, the creation mechanism of roadway contour obtained by cutting head cutting roadway is analyzed. The robot kinematics analysis method was used to determine the coordinates of the roadheader cutting head in the roadway space coordinate system, and the mathematical model of the cutting head cutting the roadway contour was constructed. Through numerical calculation, the differences of roadway morphology characteristics formed by three different types of cutting heads are analyzed. The orthogonal experiment was designed, and the regression equation under multiple factors was solved with the experimental results. The influence of cutting feed rate, cutting Angle, cutting head radius and cutting head cone Angle on the morphology characteristics of cutting surface was analyzed by regression calculation and theoretical calculation. The research results show that the roadway surface obtained by "spherical crown + cylinder" cutting head is the most uneven, and the roadway surface obtained by "spherical crown + cone + cylinder" cutting head is the most flat. With the decrease of cutting lifting Angle, cutting feed, cutting head cone Angle and the increase of cutting head crown radius, the smoothness of roadway obtained by cutting is higher.


Assuntos
Coroas , Modelos Teóricos , Fenômenos Biomecânicos
6.
Sci Rep ; 12(1): 19070, 2022 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-36351981

RESUMO

We conducted a six-month clinical follow-up on computer-aided design/computer-aided manufacturing-fabricated molar polyetheretherketone PEEK crowns to investigate their therapeutic effect. Only the PEEK crowns were examined as our study focused on short-term clinical evaluation of the new PEEK material. Twenty-three cases of PEEK crowns placed on the molars of 20 subjects (7 males and 13 females, mean age: 60.6 ± 14.2 years) were included in the study. The evaluation items were the condition of the crowns at the time of cementation and after six months, patient satisfaction, masticatory ability, and occlusal force. Mann-Whitney U tests with a significance level of 5% were used to examine the difference in glucose concentration by masticatory ability, occlusal pressure, and occlusal force, with and without PEEK crowns. The occlusion, margin fit, and contact of all 23 cases at the time of cementing were good. Six months after cementation, there was no crown desorption, fracture or crack, and prosthodontics was not needed in the 22 cases (one patient dropped out). No wear of the dental antagonist was observed. Patient satisfaction was generally high. There was no significant difference in masticatory ability between the groups with and without PEEK crowns. The subject's occlusal force was within the normal range. PEEK crowns used on molars can replace metal crowns and hold promise for an appropriate and effective treatment.


Assuntos
Coroas , Polímeros , Masculino , Feminino , Humanos , Pessoa de Meia-Idade , Idoso , Seguimentos , Benzofenonas , Cetonas , Desenho Assistido por Computador , Polietilenoglicóis
7.
J Long Term Eff Med Implants ; 33(1): 1-7, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36382699

RESUMO

The prosthetic replacement is achieved for the functional aspect of the stomatognathic system. Achieving prosthetic occlusion is challenging and has an occlusal concept of its own when the type of prosthesis varies. The implant occlusion differs for its load transfer concept and longevity. The study was employed to assess the dynamic occlusal contact in implant occlusion through digital means. The study was carried out on implant prosthesis and its dynamic parameters were evaluated using T-Scan Novus (BioResearch, Inc., Brown Deer, WI, USA) in a university hospital setting after collecting 35 patients. Mandibular arch prosthesis tends to swing from high intensity to low or no contacts frequently and when the percentage of implant crown contact at 10% is present there is more of implant protected occlusion achieved. Use of T-Scan Novus can reveal more occlusal details in functional form which can help in achieving new treatment goals.


Assuntos
Cervos , Animais , Humanos , Coroas , Próteses e Implantes
8.
Int J Esthet Dent ; 17(4): 394-406, 2022 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-36426612

RESUMO

AIM: The purpose of the present retrospective case series was to introduce a minimally invasive two-stage flapless crown lengthening procedure where a gingivectomy was avoided or minimized by reducing the bone height through a tunneling technique. MATERIALS AND METHOD: Ten patients (median age 46.6 years, range 26.9 to 71.6 years) were included in the study. The indications for performing a crown lengthening procedure were esthetically short clinical crowns (n = 5), asymmetry of the gingival margin level (n = 2), and both esthetically short clinical crowns and asymmetry of the gingival margin level (n = 3). All the patients presented a thick gingival phenotype, and the mean number of operated teeth per patient was 3.7 (range 2 to 8 teeth). Three patients underwent an additional gingivectomy 6 weeks after the crown lengthening procedure. RESULTS: The esthetic and functional outcome of the treatments fulfilled the patients' and dentist's expectations. CONCLUSION: A minimally invasive two-stage crown lengthening procedure applying a tunneling technique has the potential to achieve predictable esthetic outcomes without an open-flap approach and an additional gingivectomy. However, prospective clinical studies are needed to validate this technique.


Assuntos
Aumento da Coroa Clínica , Estética Dentária , Aumento da Coroa Clínica/métodos , Estudos Prospectivos , Estudos Retrospectivos , Coroas
9.
Int J Comput Dent ; 25(4): 361-368, 2022 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-36426840

RESUMO

AIM: There is controversy in the literature regarding clinical outcomes of CAD/CAM laminate veneers. The aim of the present study was to assess the impact of different levels of CAD expertise and different software programs on the reliability and reproducibility of digital wax patterns of laminate veneers and single crowns. MATERIALS AND METHODS: The present preliminary in vitro study was performed on 10 prepared maxillary central incisors available in dental study models. Of the total, five central incisors were prepared with shoulder finish lines for single crowns, whereas the other five underwent incisal shoulder preparation for laminate veneers. The models were scanned using an intraoral scanner. Four dentists (group DENT) and four CAD dental technicians (group CAD) with expertise in different software programs performed digital diagnostic waxing on all prepared teeth. The resulting digital wax patterns (n = 80) were exported as standard tessellation language (STL) files and superimposed on gold standard digital wax patterns (obtained from the original shape of the teeth before preparations). 3D mesh deviations at the cervical margins as well as distal, mesial, and incisal/palatal surfaces between each STL and the gold standard digital wax patterns were calculated in millimeters using a CAD software program. The mean time required by each operator to perform digital waxing was also recorded. Paired comparisons between groups DENT and CAD as well as between nondental and dental software programs were performed for the crowns and laminate veneers using the Wilcoxon signed-rank and paired t tests (α = 0.05). RESULTS: For group DENT, median deviations for single crowns were 0.15 mm (range: 0.08 to 1.05 mm) and for laminate veneers they were 0.15 mm (range: 0.08 to 0.76 mm). For group CAD, median deviations for single crowns were 0.16 mm (range: 0.09 to 0.73 mm) and for laminate veneers they were 0.10 mm (range: 0.06 to 0.53 mm). The Wilcoxon signed-rank test revealed a statistically significant difference between groups DENT and CAD (P = 0.041) and between the software programs (P = 0.029) for laminate veneers, but not for single crowns (P > 0.05). Furthermore, mean times required for group CAD and for dental software programs were significantly shorter than those for group DENT (P = 0.001) and for nondental software programs (P = 0.001), respectively. CONCLUSION: Within the limitations of the present study, the findings suggest that CAD expertise and the software program significantly affect digital wax patterns for laminate veneers, but not for single crowns. (Int J Comput Dent 2022;25(4):361-0; doi: 10.3290/j.ijcd.b3555819).


Assuntos
Planejamento de Prótese Dentária , Facetas Dentárias , Humanos , Reprodutibilidade dos Testes , Planejamento de Prótese Dentária/métodos , Porcelana Dentária , Desenho Assistido por Computador , Coroas
10.
BMC Oral Health ; 22(1): 516, 2022 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-36402987

RESUMO

BACKGROUND: This in-vitro study was conducted to assess the effect of aging on the fracture load of molar crowns fabricated with monolithic CAD/CAM materials. METHODS: The crown restorations were produced from Cerasmart, Vita Enamic, and IPS e.max CAD blocks. Aging was applied to the 10 samples each of monolithic CAD/CAM materials (n = 10). Dual-axis chewing simulator (50 N, 1.1 Hz, lateral movement: 1 mm, mouth opening: 2 mm, 1,200,000 cycles) and thermocycling (± 5-55 °C, 6000 cycles) were applied as an aging procedure. 10 samples each of monolithic CAD/CAM materials without aging (n = 10) were considered the control group. 6 tested groups were obtained. Then, all samples were evaluated in a universal testing machine to determine the fracture loading values'. RESULTS: There was not a statistically significant difference between the fracture load values before and after aging for all samples of Cerasmart, Vita Enamic, and IPS e.max CAD (p > 0.005). In a comparison of the monolithic materials together, a statistically significant difference was found between the fracture load values of IPS e.max CAD and Vita Enamic crowns before aging (p = 0.02). Also, Vita Enamic crowns (1978,71 ± 364,05 N) were found different from the IPS e.max CAD (p = 0.005) and Cerasmart crowns (p = 0.041) after aging. CONCLUSIONS: Dynamic aging with 1.200.000 cycles was found to have no effect to fracture loading on milled Cerasmart, Vita Enamic, and IPS e.max CAD monolithic crowns.


Assuntos
Coroas , Porcelana Dentária , Humanos , Teste de Materiais , Desenho Assistido por Computador , Envelhecimento
11.
BMC Oral Health ; 22(1): 517, 2022 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-36403015

RESUMO

OBJECTIVE: The purpose of this study was to compare the usefulness of intraoral photographs, acquired with a household intraoral camera operating in conventional, calibrated, and polarized modes, with clinical examinations for assessing the marginal adaptation and gingival status of full-crown restorations. METHODS: Clinical examinations were performed by a prosthodontist who classified the marginal adaptation of full-crown restorations according to FDI World Dental Federation criteria, and a periodontal expert who classified gingival status according to the Modified Gingival Index (MGI). The margins and gingival status of the conventional, calibration, and polarization groups of full-crown restorations were independently assessed by three evaluators who obtained photographs using an intraoral camera. Cases where at least two of three assessors were in agreement were analyzed using Cohen's kappa coefficient and the chi-square test, and the sensitivity and specificity were calculated. RESULTS: The conventional, calibration, and polarization groups differed significantly in marginal and gingival status of full-crown restorations. In the calibration group, there was good agreement between the camera-based and oral clinical examinations in terms of the gingival status of full-crown restorations (kappa = 0.945), with 100% sensitivity and 91.67% specificity; this was also the case in the polarization group with respect to the margins of full-crown restorations (kappa = 0.917, sensitivity = 97.22%, specificity = 94.44%). CONCLUSIONS: An intraoral camera with black and white calibrated images is useful to assess the gingival status of full-crown restorations. Polarization mode can be used to assess the marginal adaptation of full-crown restorations. The camera is a feasible and valid diagnostic aid.


Assuntos
Assistência Odontológica , Gengiva , Humanos , Fotografia Dentária , Índice Periodontal , Coroas
12.
Medicina (Kaunas) ; 58(11)2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36363569

RESUMO

Dental implants have been placed millions of times worldwide, and the surgical procedure and implant design have steadily improved. The basic prosthetic connection, which makes use of an abutment, has changed little over the past decades. These days, implant placement with immediate provisionalization is an essential stage in implant dentistry and interdisciplinary treatment strategies. Temporary computer-aided design and computer-aided manufacturing (CAD/CAM) of implant-supported crowns restore esthetics and guarantee function during the restoration process and the osseointegration of the dental implant. This case report describes the digital planning; the immediate, static, computer-assisted implant surgery, and the immediate chairside provisionalization of a novel implant system that is directly screw-retained without an abutment.


Assuntos
Coroas , Cirurgia Assistida por Computador , Humanos , Fluxo de Trabalho , Desenho Assistido por Computador , Parafusos Ósseos
13.
BMC Oral Health ; 22(1): 493, 2022 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-36380324

RESUMO

BACKGROUND: Short-term sintering may offer advantages including saving time and energy but there is limited evidence on the effect that altering sintering time has on the accuracy of monolithic zirconia crowns. The purpose of this in vitro study was to investigate the effect of shortened sintering time on the marginal and internal fit of 3Y-TZP and 4Y-TZP monolithic crowns. METHODS: Sixty monolithic zirconia crowns were fabricated for the maxillary first molar tooth on the prefabricated implant abutment. Groups were created according to the material composition: 3Y-TZP Generation 1, 3Y-TZP Generation 2 and 4Y-TZP. Two different sintering protocols were performed: same final sintering temperature (1500 °C) and various rates of heating (10 °C/min and 40 °C/min), cooling down speed (- 10 °C/min and - 40 °C/min), holding time (45 and 120 minutes), and total sintering time (approximately 2 and 7 hours, respectively). The marginal and internal fit of the crowns were determined using the silicone replica technique. Comparisons between groups were analyzed using two-way ANOVA. Pairwise multiple comparisons were performed using t-test (p < 0.05). RESULTS: The mean marginal gap values of 4Y-TZP zirconia revealed statistically significant increase for the short-term sintering protocol (p < 0.0001), while no difference was observed between the sintering protocols for the mean marginal gap values of 3Y-TZP groups. Although all groups showed clinically acceptable gap values, altering the sintering time had an effect on marginal fit of the crowns manufactured from 4Y-TZP zirconia. CONCLUSIONS: Shortening the sintering time may lead to differences within clinically acceptable limits. The manufacturer's recommendations according to material composition should be implemented with care.


Assuntos
Desenho Assistido por Computador , Planejamento de Prótese Dentária , Humanos , Planejamento de Prótese Dentária/métodos , Coroas , Zircônio , Teste de Materiais
14.
Shanghai Kou Qiang Yi Xue ; 31(3): 260-264, 2022 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-36204953

RESUMO

PURPOSE: To evaluate the clinical effect of three-dimensional digital smile design (3D-DSD) combined with double positioning crown extension guide in aesthetic restoration of anterior teeth. METHODS: Twenty patients who needed aesthetic crown lengthening and full crown restoration of upper anterior teeth were selected and randomly divided into the experimental group and control group, with 10 cases in each group. The experimental group carried out 3D-DSD, after confirming the plan, 3D printed double positioning crown extension guides were used to guide aesthetic crown lengthening, and full crown was completed 3 months after operation. The control group used traditional aesthetic crown lengthening and full crown restoration. PES/WES evaluation was performed before operation, three months and six months after operation. Visual analogue scales(VAS) were used to evaluate patient satisfaction 6 and 7 months after surgery, and the repeatability evaluation of VAS was conducted. The correlation between PES/WES score and overall satisfaction was analyzed 6 months after operation. SPSS 23.0 software package was used for statistical analysis. RESULTS: The PES/WES scores of the two groups of patients at 3 months and 6 months after operation were higher than those before operation(P<0.05). The two groups showed that the scores of the experimental group were significantly higher than those of the control group for PES 3 months after operation, PES and WES 6 months after operation(P<0.05).Satisfaction survey results showed that the intra-group correlation coefficient of the two VAS results was 0.956(P<0.05),and crown length-to-width ratio, smile curve, personality characteristics, patient participation and overall satisfaction in the experimental group were better than those of the control group(P<0.05).The results of Speraman correlation analysis showed that PES and WES scores at 6 months after operation were positively correlated with overall satisfaction (rs1=0.905, P<0.001; rs2=0.460, P=0.041). CONCLUSIONS: 3D digital smile design combined with double positioning crown extension guide guides the anterior aesthetic crown lengthening and restoration treatment, which can improve the effect of pink and white aesthetics after treatment and patient satisfaction.


Assuntos
Implantes Dentários para Um Único Dente , Coroas , Estética Dentária , Humanos , Satisfação do Paciente , Resultado do Tratamento
15.
Shanghai Kou Qiang Yi Xue ; 31(3): 305-308, 2022 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-36204962

RESUMO

PURPOSE: To investigate the effect of different implant systems on peri-implant soft tissue. METHODS: Forty patients requiring single implant therapy in posterior teeth at Dental and Ophthalmic Clinic of Putuo District from December 2020 to February 2021 were selected. Ten patients were implanted with bone level implants and 30 patients with soft tissue level implants. Periodontal exploration was performed at the buccal side, lingual side, mesial and distal axial angle of the implants, and the gingival crevicular fluid of these locations were taken to detect the enzyme level. The probing depth, aspartate aminotransferase (AST) and alkaline phosphatase (ALP) level of the two groups were compared at the day, 3 months, 6 months and 12 months after crown restoration. Statistical analysis was completed by SPSS 17.0 software package. RESULTS: The probing depth and ALP level of soft tissue level implants were significantly lower than those of bone level implants at the day, 3 months, 6 months and 12 months after crown restoration(P<0.05). At the day when crown restoration was accomplished, AST of soft tissue implant was significantly lower than that of bone level implant(P<0.05). AST in gingival crevicular fluid of bone level implants decreased rapidly in the following three time periods, and close to that of the soft tissue level implants(P>0.05) at last. CONCLUSIONS: Both bone level implants and soft tissue level implants have good clinical effects, but peri-implant soft tissues of the soft tissue level implants show better stability.


Assuntos
Fosfatase Alcalina , Implantes Dentários , Aspartato Aminotransferases , Coroas , Implantação Dentária Endóssea , Líquido do Sulco Gengival , Humanos
16.
Shanghai Kou Qiang Yi Xue ; 31(3): 313-317, 2022 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-36204964

RESUMO

PURPOSE: To analyze the clinical effect of digital impression combined with all-ceramic denture restoration on patients with dental defects. METHODS: A study was conducted on 120 patients with dental defects admitted to Dongfeng Stomatological Hospital from June 2018 to June 2020. The two groups of patients were randomly divided into digital imprinting modules and silicone rubber imprinting modules using a random number table method. There were 60 cases in each group. The silicone rubber imprint module used traditional silicone impression combined with all-ceramic denture restoration, while the digital imprint module used digital impression combined with all-ceramic denture restoration.The clinical efficacy of the two groups was observed. Gingival index (GI), periodontal index (PI) before dental restoration, during dental restoration and 6 monthes after dental restoration were compared. The adjacent surface contact conditions, occlusion and adverse reactions of the two groups were compared. SPSS 22.0 software package was used for statistical analysis. RESULTS: The two groups of patients selected grade A and grade B for the evaluation of the restoration when the restoration was completed. The number of patients who chose grade A for the digital imprint module was more than that of the silicone rubber imprint module,but there was no significant difference(P>0.05). Six months after the tooth was worn, GI and PI indexes of the two groups of patients increased. GI and PI indexes of the silicone rubber stamping module were significantly higher than those of the digital stamping module(P<0.05). When dental restoration was completed and 6 months after the tooth was replaced, the pass rate of contact between the adjacent surfaces of the imprinting module patients was significantly higher than that of the silicone rubber imprinting module(P<0.05). When dental restoration was completed, the occlusion of the digital imprinting module patients was significantly better than that of the silicone rubber imprinting module(P<0.05). Six months after wearing the denture, there was no significant difference in occlusion between the two groups of patients(P>0.05). When dental models of the two groups of patients were taken, the incidence of adverse reactions in patients with digital imprints was significantly lower than that of silicone rubber imprints(P<0.05). CONCLUSIONS: The use of digital impressions combined with all-ceramic restorations to repair patients with dental defects can effectively improve the treatment effect, improve prognostic GI and PI indexes of the patients, increase the pass rate of the adjacent surface contact and occlusion of the tooth, and reduce the process of dental restoration. The incidence of adverse reactions are minimal, with good prognostic effects. It is worthy of clinical application.


Assuntos
Coroas , Porcelana Dentária , Cerâmica , Desenho Assistido por Computador , Técnica de Moldagem Odontológica , Planejamento de Prótese Dentária/métodos , Dentaduras , Humanos , Elastômeros de Silicone
17.
Dent Mater ; 38(11): 1812-1825, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36192277

RESUMO

OBJECTIVES: This study aimed to determine the effects of the postwashing method and time on the mechanical properties and biocompatibility of three-dimensional (3D) printed crown and bridge resin. METHODS: DLP (digital light processing)-printed specimens produced from Nextdent crown & bridge (C&B) resins were washed separately using an ultrasonic bath and rotary washer with TPM (tripropylene glycol monomethyl ether) for 3 min, 6 min, 10 min, 20 min, and 1 h. Postcuring was applied for 30 min to each specimen after the washing process. The flexural strength, Vickers hardness, water sorption and solubility, degree of conversion (DC), elution of residual monomers, and biocompatibility of the specimens were evaluated. RESULTS: The ultrasonic bath showed greater washing efficacy by reducing the residual HEMA (2-hydroxyethyl methacrylate) from 2.0634 ppm to 0.1456 ppm and reducing the residual TEGDMA (triethylene glycol dimethacrylate) from 1.4862 ppm to 0.1484 ppm. With prolonged washing, the flexural strength significantly decreased from 129.67 ± 6.66 MPa (mean±standard deviation) to 103.17 ± 7.20 MPa, while the Vickers hardness increased slightly for the first 6 min and then decreased thereafter significantly. The DC was 87.78 ± 1.34% after 3 min and then gradually decreased with extended washing time. The cytotoxicity significantly decreases with the increment of the washing time. SIGNIFICANCE: The washing effect on the elution of residual monomers was better for an ultrasonic bath than for a rotary washer. Extending the washing time reduces the mechanical properties and cytotoxicity of the Nextdent C&B resin.


Assuntos
Resinas Compostas , Coroas , Éteres , Teste de Materiais , Metacrilatos , Polietilenoglicóis , Ácidos Polimetacrílicos , Impressão Tridimensional , Água
18.
Medicina (Kaunas) ; 58(10)2022 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-36295521

RESUMO

Background and Objectives: The report describes a technique using a diagnostic mock-up as a crown-lengthening surgical guide to improve the gingival architecture. Materials and Methods: The patient's primary concern was improving her smile due to her "gummy smile" and short clinical crowns. After clinical evaluation, surgical crown lengthening accompanied by maxillary central full-coverage single-unit prostheses and lateral incisor veneers was recommended. The diagnostic mock-up was placed in the patient's maxillary anterior region and used as a soft tissue reduction guide for the gingivectomy. Once the planned gingival architecture was achieved, a flap was reflected to proceed with ostectomy in order to obtain an appropriate alveolar bone crest level using the overlay. After six months, all-ceramic crowns and porcelain veneers were provided as permanent restorations. Results: A diagnostic mock-up fabricated with a putty guide directly from the diagnostic wax-up can be an adequate surgical guide for crown-lengthening procedures. The diagnostic wax-up was used to fabricate the diagnostic mock-up. These results suggested that it can be used as a crown-lengthening surgical guide to modify the gingival architecture. Several advantages of the overlay used in the aesthetic complex case include: (1) providing a preview of potential restorative outcomes, (2) allowing for the appropriate positioning of gingival margins and the desired alveolar bone crest level for the crown-lengthening procedure, and (3) serving as a provisional restoration after surgery. Conclusions: The use of a diagnostic mock-up, which was based on a diagnostic wax-up, as the surgical guide resulted in successful crown lengthening and provisional restorations. Thus, a diagnostic overlay can be a viable option as a surgical guide for crown lengthening.


Assuntos
Aumento da Coroa Clínica , Porcelana Dentária , Humanos , Feminino , Aumento da Coroa Clínica/métodos , Gengivectomia/métodos , Coroas , Incisivo
19.
Pediatr Dent ; 44(5): 368-374, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36309781

RESUMO

Purpose: The purpose of this in vitro study was to compare the fracture resistance and survival of various esthetic crowns for primary molars after artificial aging via chewing simulation. Methods: A typodont tooth (mandibular primary second molar) was prepared to receive five different types of crowns as follows (n equals 10): prefabricated fiberglass (PF); CAD/CAM zirconia (CZ); CAD/CAM resin-ceramic (CR); composite- strip (CS); and prefabricated zirconia (PZ) as control. All specimens were subjected to 750,000 cycles of thermomechanical loading to artificially simulate three years of clinical service. None of the crowns from the CS group survived artificial aging. Surviving crowns were evaluated via micro-CT considering microcrack formation, and a load-to-fracture test was applied. Data were analyzed using one-way analysis of variance followed by the Duncan test. Results: Group PZ (557.4±170.1 N) and CR (669.6±255.2) were found to have comparable results (P >0.05), which were lower than the other groups (P<0.05). Group CZ resulted in the highest mean load-to-fracture value (1126.2±180.6; P <0.05). At the end of three years of artificial aging, microcracks were observed for only CS and PF groups. Conclusions: These in vitro data suggest that all tested crowns, except CS crowns, survived three years of artificial aging; however, CAD/CAM zirconia crowns may provide longer service, as they showed the highest fracture resistance with no microcrack formation.


Assuntos
Falha de Restauração Dentária , Estética Dentária , Humanos , Análise do Estresse Dentário , Teste de Materiais , Coroas , Zircônio , Dente Molar
20.
Pediatr Dent ; 44(5): 363-367, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36309785

RESUMO

Purpose: The purpose of this study was to evaluate the surface roughness of three different brands of prefabricated pediatric zirconia crowns (ZRCs) following simulated toothbrushing with a variety of dentifrices. Methods: Ninety-six total maxillary right central incisor prefabricated pediatric ZRCs (n equals 32 ZRCs/brand) were obtained from the manufacturers: Kinder Krowns®, NuSmile®, and Sprig®. ZRCs were equally assigned to dentifrices (n equals eight/dentifrice) with a variety of Relative Dentin Abrasion (RDA) values: Tom's of Maine Children's; Crest Kid's; Prevident 5000; and Crest® Pro-Health. ZRCs were brushed 10,000 strokes with a V-8 Toothbrushing Machine using the assigned dentifrices. Pre- and post-intervention data for the surface roughness of ZRCs, represented in Ra (average roughness) and Rz (mean roughness depth), were obtained using a stylus profilometer. Data were analyzed independently using two-way repeated measures analysis of variance with the Holm- Sidak method (α equals 0.05). Results: Baseline versus brushed Ra Kinder Krowns® with Prevident and Sprig® with Crest Kid's indicated statistically significant differences. Sprig® versus NuSmile® utilizing Crest Kid's were different in change in roughness. Both baseline and brushed NuSmile® dentifrice options were different versus all Sprig® and Kinder® ZRCs. Conclusions: Despite statistical significance, changes in surface roughness were small in scale. Although this study did not address toothbrushing and different dentifrices may affect the mechanical properties, durability, and/or retention properties of ZRCs, the study's results provide confidence to clinicians when using prefabricated pediatric ZRCs as a sustainable treatment option along with other restorative options, such as strip crowns and stainless steel crowns.


Assuntos
Dentifrícios , Escovação Dentária , Humanos , Criança , Escovação Dentária/métodos , Propriedades de Superfície , Coroas
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