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1.
Rev. Odontol. Araçatuba (Impr.) ; 42(3): 25-31, set.-dez. 2021. ilus
Artigo em Português | LILACS, BBO - Odontologia | ID: biblio-1284114

RESUMO

Os pilares personalizados são usados em reabilitações protéticas sobre implantes quando há exigências de angulação, perfil de emergência e margem gengival, em que os pilares convencionais não conseguem reabilitar de forma correta os conceitos de forma, função e estética. Através de um relato de caso clínico, onde houve a reabilitação dos elementos 21 e 22, com o uso de implante e próteses, usando o pilar personalizado em zircônia sobre o implante do 22, confeccionado com a tecnologia CAD/CAM. Esse sistema de pilares personalizados oferecem o desenho mais próximo do ideal e o ajuste mais perfeito em relação ao implante e ao tecido gengival, além de considerar as vantagens e desvantagen em relação aos pilares convencionais pré-fabricados nas questões de tempo de tratamento, custos e resultado estético e biológico. Concluimos que a reabilitação com pilares personalizados CAD/CAM confere uma excelente alternativa reabilitadora, devolvendo função e estética aos pacientes, desde que haja conhecimento adequado por parte dos profissionais envolvidos(AU)


Custom abutments are used in prosthetic rehabilitation on implants when angulation, emergence profile and gingival margin are used, where abutments are not recovered in a correct way to rehabilitate the concepts of shape, functions and aesthetics. Through a clinical case, where the elements 21 and 22 were rehabilitated, with the use of implants and practices, using the personalized abutments in zirconia, made with CAD / CAM technology. This customized system and abutments offers the closest ideal design and the most perfect fit in relation to the implant and gingival tissue, in addition to considering advantages and disadvantages in relation to the prefabricated applied abutments in terms of treatment time, costs and results aesthetic and biological. Conclude that a rehabilitation with customized CAD / CAM abutments provides an excellent rehabilitation alternative, returning function and aesthetics to patients, as long as there is adequate knowledge for part of the professionals involved(AU)


Assuntos
Humanos , Feminino , Idoso , Implantes Dentários , Desenho Assistido por Computador , Materiais Biocompatíveis , Prótese Dentária Fixada por Implante , Estética Dentária
2.
Braz. j. oral sci ; 20: e214873, jan.-dez. 2021. ilus
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-1254742

RESUMO

Aim: To compare the marginal fit of lithium disilicate CAD/CAM crowns and heat-pressed crowns fabricated using milled wax patterns, and evaluate its effect on stress distribution in implantsupported rehabilitation. Methods: A CAD model of a mandibular first molar was designed, and 16 lithium disilicate crowns (8/group) were obtained. The crown-prosthetic abutment set was evaluated in a scanning electron microscopy. The mean misfit for each group was recorded and evaluated using Student's t-test. For in silico analysis, a virtual cement thickness was designed for the two misfit values found previously, and the CAD model was assembled on an implant-abutment set. A load of 100 N was applied at 30° on the central fossa, and the equivalent stress was calculated for the crown, titanium components, bone, and resin cement layer. Results: The CAD/CAM group presented a significantly (p=0.0068) higher misfit (64.99±18.73 µm) than the heat-pressed group (37.64±15.66 µm). In silico results showed that the heat-pressed group presented a decrease in stress concentration of 61% in the crown and 21% in the cement. In addition, a decrease of 14.5% and an increase of 7.8% in the stress for the prosthetic abutment and implant, respectively, was recorded. For the cortical and cancellous bone, a slight increase in stress occurred with an increase in the cement layer thickness of 5.9% and 5.7%, respectively. Conclusion: The milling of wax patterns for subsequent inclusion and obtaining heat-pressed crowns is an option to obtain restorations with an excellent marginal fit and better stress distribution throughout the implant-abutment set


Assuntos
Microscopia Eletrônica de Varredura , Desenho Assistido por Computador , Adaptação Marginal Dentária , Prótese Dentária Fixada por Implante , Análise de Elementos Finitos , Materiais Dentários
3.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 56(9): 920-925, 2021 Sep 09.
Artigo em Chinês | MEDLINE | ID: mdl-34496543

RESUMO

Objective: To establish a standard method to evaluate the scanning accuracy of intraoral scanner (IOS) and to investigate six IOS's scanning accuracy and the relationship between different scan span. Methods: Five simplified six abutments full arch model were fabricated by high accuracy (5 µm) milling machine with 7075 aluminum alloy. The machining accuracy, which was verified by a coordinate measuring machine with higher accuracy (0.7 µm), was considered as the reference accuracy. The model with the highest machining accuracy was considered as the test model in IOS's scanning accuracy test, and computer-aided design (CAD) data of the model was used as the reference data. Six IOS scanned the test model 10 times with the same scanning path, obtained 60 test data. CAD data and test data were input into Geomagic Studio 2014. The preparation part above the margin of the abutments of the data was isolated and divided into 4 segments of interest: single crown, three-unit bridge, five-unit bridge, and full arch. The test data were then best-fit aligned to CAD data or each other followed by deviation analysis. Scanning trueness and precision were then calculated. Results: The mid-value of scanning trueness and precision of six IOS in single crown, three-unit bridge, five-unit bridge and full arch were 13.3-29.6 µm and 7.6-20.7 µm, 15.4-30.9 µm and 8.7-26.5 µm, 17.0-66.1 µm and 11.3-44.2 µm, 24.0-107.9 µm and 24.6-150.1 µm respectively. Conclusions: Long-span scanning can affect the accuracy of IOS to a varying extent.


Assuntos
Técnica de Moldagem Odontológica , Dente , Desenho Assistido por Computador , Arco Dental , Modelos Dentários , Imageamento Tridimensional
4.
Chin J Dent Res ; 24(3): 185-189, 2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34491013

RESUMO

OBJECTIVE: To evaluate the clinical performance of direct composite restorations using the modified stamp technique (MST) in vivo. METHODS: A total of 30 posterior teeth with undermining caries were randomly divided into two groups and then restored using the MST and conventional technique (CT), respectively. 3D images of the occlusal surface were obtained using an intraoral scanner (CEREC Omnicam, Dentsply Sirona, Charlotte, NC, USA) before and after treatment and the differences between these two 3D images were analysed with reverse engineering software. Statistical analysis was performed using a one-way analysis of variance (ANOVA) combined with a least significant difference (LSD) post hoc test using SPSS 20.0 software (IBM, Armonk, NY, USA). RESULTS: The statistical analysis revealed that the average root mean square (RMS) values of best fit alignment errors were significantly different between groups (P < 0.01). The average RMS values in the MST and CT groups were 0.0738 ± 0.0279 and 0.1638 ± 0.0682, respectively. The LSD post hoc test revealed that the value was significant smaller in the MST group than in the CT group. CONCLUSION: The MST was effective in direct composite restoration. The morphological consistency of the occlusal surface using the MST was better than with the CT.


Assuntos
Desenho Assistido por Computador , Dente , Resinas Compostas , Restauração Dentária Permanente , Imageamento Tridimensional
5.
J Indian Prosthodont Soc ; 21(3): 240-248, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34380810

RESUMO

Aim: The aim of the present study was to clinically assess the performance of BioHPP PEEK material when used for inlay restoration and to compare it with widely used zirconia inlays. This clinical study was undertaken to evaluate their performance in terms of retention, colour matching, marginal discoloration, marginal adaptation, secondary caries, surface texture, wear-anatomic form, postoperative sensitivity and fracture resistance using the modified Ryge's criteria. Settings and Design: In vivo - prospective clinical study. Material and Methods: A total of 40 patients were selected based on inclusion and exclusion criteria requiring inlays. The patients were further divided in two groups: Group A - Consisted of 20 permanent maxillary and mandibular carious posterior teeth restored with BioHPP PEEK inlays and Group B - Consisted of 20 permanent maxillary and mandibular carious posterior teeth restored with CAD/CAM zirconia inlays (sintered monolithic zirconia, Zolid, Amann Girrbach AG, Koblach, Austria). Two prosthodontists, who were blinded to the study groups, evaluated the restorations. In cases of widely different scores, the observers re-evaluated the restorations and reached a consensus. Restorations were evaluated at the end of 1 week (base line), 3 months, 6 months, and 12 months, using modified Ryge's criteria. Statistical Analysis Used: Chi- square' test, 'Fisher's exact' test and 'z' test. Results: 90% of the BioHPP PEEK inlays were rated satisfactory in comparison to 95% of zirconia inlays. Sensitivity score was 10% in BioHPP PEEK inlays and 15% in zirconia inlays. No significant difference was encountered with other parameters in this study. Conclusion: The BioHPP PEEK when used as indirect aesthetic restorations was found to be satisfactory with relatively low rate of fracture over an observation period of one year in comparison to zirconia inlays in posterior teeth. The BioHPP PEEK can be a suitable alternative with high level of accuracy in terms of retention, marginal quality and aesthetics.


Assuntos
Desenho Assistido por Computador , Cetonas , Benzofenonas , Humanos , Polímeros , Estudos Prospectivos , Zircônio
6.
J Indian Prosthodont Soc ; 21(3): 269-275, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34380814

RESUMO

Aim: Assess the retention of endocrowns fabricated of different CAD/CAM materials. Settings and Design: In vitro - comparative study. Material and Methods: Root canal treated mandibular first molars were prepared in a standardized method. Standardized endocrowns were manufactured using four CAD-CAM blocks: resin infiltrated ceramic (Vita Enamic), partially stabilized tetragonal zirconia (Katana), lithium disilicate ceramic (IPS e.max CAD), and polyether-ether-keton (PEEK, BioHPP). After proper surface treatment, the restorations were cemented using a resin cement (Panavia F2.0) and were connected to a special attachment unit and secured to a universal testing machine. The amount of axial load required to dislodge the restoration from the tooth structure was measured (n = 12, α = 0.05). Failures were classified as adhesive debonding from the tooth structure without damaging the supporting tooth structure and cohesive fracture of the supporting tooth structure. Statistical Analysis Used: One-way analysis of variance,Tukey's post hoc test. Results: The retention of Vita Enamic (61 ± 11 N) and IPS e.max CAD (58 ± 9 N) was significantly higher (F = 123, P < 0.01) than Katana (33 ± 13) and Peek restorations (23 ± 11). Vita Enamic and IPS e.max CAD were associated with fractured tooth segments during debonding while Katana and PEEK specimens were adhesively debonded from the remaining tooth structure. Conclusions: Within the limitations of this study, using lithium disilicate ceramics and resin infiltrated ceramics as restorative materials to fabricate endocrowns to restore severely damaged endodontically treated teeth, recorded significantly higher retention values. Meanwhile, using yttrium partially stabilized zirconia and polyether ether ketones for the same purpose recorded a favorable mode failure which avoided the possibility of tooth fracture.


Assuntos
Dente não Vital , Desenho Assistido por Computador , Humanos , Teste de Materiais , Dente Molar , Cimentos de Resina
7.
Artigo em Inglês | MEDLINE | ID: mdl-34444195

RESUMO

This in vitro study aimed to evaluate the 3D analysis for complete arch, half arch, and tooth preparation region by using four analysis software programs. The CAD reference model (CRM; N = 1 per region) and CAD test models (CTMs; N = 20 per software) of complete arch, half arch, and tooth preparation were obtained by using scanners. For both CRM and CTMs, mesh data other than the same area were deleted. For 3D analysis, four analysis software programs (Geomagic control X, GOM Inspect, Cloudcompare, and Materialise 3-matic) were used in the alignment of CRM and CTMs as well as in the 3D comparison. Root mean square (RMS) was regarded as the result of the 3D comparison. One-way analysis of variance and Tukey honestly significant difference tests were performed for statistical comparison of four analysis software programs (α = 0.05). In half-arch and tooth preparation region, the four analysis software programs showed a significant difference in RMS values (p < 0.001), but in complete-arch region, no significant difference was found among the four software programs (p = 0.139). As the area of the virtual cast for 3D analysis becomes smaller, variable results are obtained depending on the software program used, and the difference in results among software programs are not considered in the 3D analysis for complete-arch region.


Assuntos
Desenho Assistido por Computador , Imageamento Tridimensional , Software
8.
Artigo em Inglês | MEDLINE | ID: mdl-34443993

RESUMO

The fabrication of a non-metal clasp removable partial denture (RPD) using polymethylmethacrylate in a fully digital workflow has been reported. According to some studies, the polyamide material may be alternatively used for this purpose. The authors are unaware of any reports concerning the additive manufacturing of polyamide. The current proof-of-concept dental technique describes the pathway to construct the non-metal clasp RPD using intraoral scanning and fused filament fabrication (FFF) printing of gingiva-colored polyamide. The present RPD showed acceptable fit and sufficient retention and was considered a valid temporary treatment option.


Assuntos
Prótese Parcial Removível , Desenho Assistido por Computador , Nylons , Impressão Tridimensional , Fluxo de Trabalho
9.
Gen Dent ; 69(5): 52-55, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34424213

RESUMO

The endocrown is a ceramic restoration that combines a core and a crown into a single structure. This restoration can be useful for endodontically treated teeth, for which traditional crown preparation can be difficult. Although most of these restorations are fabricated using single-visit computer-aided design/computer-aided manufacturing technology, they can also be fabricated by a laboratory using traditional polyvinyl siloxane impressions. This article will review the concept of endocrowns and describe 3 clinical situations in which an endocrown was utilized for the restoration of a compromised endodontically treated tooth.


Assuntos
Dente não Vital , Cerâmica , Desenho Assistido por Computador , Coroas , Planejamento de Prótese Dentária , Humanos , Dente não Vital/terapia
10.
J Biol Regul Homeost Agents ; 35(4 Suppl. 1): 1-9, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34425656

RESUMO

Nowadays, the objective of esthetic rehabilitation is not only to guarantee the results to the patients in terms of esthetic parameters but also the possibility to show the pre-visualization of possible results and therapy planning. OBJECTIVE: The aim of this study is to apply the 3D-DPS digital planning technique, in the prosthetic treatment of a patient, to produces digitally the mockup for the digital previewing and esthetic crown and veneer for the final prosthetic treatment. MATERIALS AND METHODS: A case report participant is a young patient, a female, 26 years old, with no oral, periodontal, or systemic diseases. After a sign of an informed consent and an explication of a plan of treatment, technical intraoral and extraoral pictures and intraoral digital impressions were taken. The digital images improved from the 2D Smile Lynx Software and the scanner stereolithographic (STL) file was matched into the CAD Lynx to obtain a virtual previsualization of teeth and smile design. Then, the mockup was milled using a CAM system. Minimally invasive preparation was carried out on the enamel surface with the mockup as position guides. Finally, the esthetic CAD-CAM veneer and crown were produced digitally using the CAD Wax as a guide. RESULTS: The use of the digital project and the pre-operative mockup allowed a perfect initial evaluation and a better understanding of the patient's treatment plan. CONCLUSIONS: The 3D digital planning technique is a new, predictably and minimally invasive technique. It allows diagnosis and a better communication with the patient. It helps to reduce the working time and the possible errors usually associated with the classical prosthodontic manual step.


Assuntos
Estética Dentária , Dente , Adulto , Desenho Assistido por Computador , Feminino , Humanos , Técnicas de Planejamento , Sorriso
11.
J Biol Regul Homeost Agents ; 35(4 Suppl. 1): 11-29, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34425657

RESUMO

The aim of this clinical study is to present an integrated digital project through the description of a clinical case, made entirely in digitized form, taking advantage of the opportunity offered by instrumental diagnostic software. A case report participant is a 65-year-old female patient presents with loss of diffuse bone support, caused by periodontal disease. After a sign of an informed consent and an explication of a plan of treatment, technical intraoral and extraoral pictures and intraoral digital impressions were taken. The digital images improved from the 2D Smile Lynx Software and the scanner stereolithographic (STL) file was matched into the CAD Lynx to obtain a virtual previsualization of teeth and smile design, and to mill the provisional and the definitive crowns. The digital prosthetic design allows the evaluation of the dental parameters in relation to the parameters of the patient's face for the new prosthetic project and the radiological examination using CBCT guides the insertion of the fixtures for the rehabilitation phase. The surgical and prosthetic design are subsequently integrated. The evaluation of the bone bases is carried out with a radiological diagnostic software for CT (Real Guide 5.0-3Diemme, Cantù-Italy) which can virtually design the implant insertion. The functional examination of the patient is carried out through an occlusion-postural examination that uses digital electromyographic assessments. The integrated digital protocol proposal inserts in the rehabilitation path the digital recording of the free mandibular movement, as well as the scan of the patient's face, data that will be integrated into the CAD software for the design of temporary and definitive prosthetic artifacts, made using the CAM method. This study showed guided implant placement and the application of fixed implant-supported prosthetic restorations carried out with a fully digital workflow, dependent on the functional digital evaluation of the patient's occlusion. The proposed protocol described the correct use of digitalization of clinical, surgical, and prosthetic procedures, and the matching of the data into a computerized environment, to improve team communication and to take advantage of the combination of collected data to not lose information using classic manual steps.


Assuntos
Desenho Assistido por Computador , Cirurgia Assistida por Computador , Idoso , Protocolos Clínicos , Computadores , Feminino , Humanos , Mandíbula
12.
Am J Orthod Dentofacial Orthop ; 160(2): 302-311, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34332692

RESUMO

INTRODUCTION: Computer-aided design and manufacturing of orthodontic retainers from digitally debonded models can be used to facilitate same-day delivery. The purpose of this prospective clinical study was to validate a novel technique for virtual bracket removal (VBR) in-office, comparing the accuracy with 2 orthodontic laboratories that use VBR for retainer fabrication in the digital workflow. METHODS: The sample consisted of 40 intraoral scans of 20 patients. Four groups were compared. The scans without brackets were used as a control group. VBR was performed by 3 groups: In-office VBR (Software Meshmixer, version 3.5.474; Autodesk, San Rafael, Calif), Orthodent Laboratory (ODL; Buffalo, NY), and New England Orthodontic Laboratory (NEOLab; Andover, Mass). The virtually debonded models were superimposed onto the control models using surface-based registration. Regional 3-dimensional Euclidean distances between surface points of superimposed models were calculated for comparative analysis of surface changes after VBR using Vector Analysis Module (Canfield Scientific, Fairfield, NJ) software. RESULTS: The accuracy of VBR using the Meshmixer did not differ significantly from the VBR protocols used by the 2 laboratories. However, there was a statistically significant difference between the 2 laboratories, with ODL showing lower accuracy than NEOLab. Although some differences were statistically significant, they were very small and not considered clinically relevant. There was also a statistically significant difference between the 3 tooth segments (incisors, canines/premolars, and first molars), with VBR of the first molars and second premolars showing the least accuracy. CONCLUSIONS: The VBR techniques using the in-office Meshmixer, ODL, and NEOLab were considered accurate enough for the clinical use of orthodontic retainers fabricated from printed models.


Assuntos
Braquetes Ortodônticos , Contenções Ortodônticas , Dente Pré-Molar , Desenho Assistido por Computador , Humanos , Dente Molar , Estudos Prospectivos
13.
Artigo em Inglês | MEDLINE | ID: mdl-34360288

RESUMO

CAD/CAM technology can enhance the dentistry application of ceramic materials that meet the more relevant biocompatibility and aesthetics demands. In implant-borne prosthesis rehabilitation, yttria-stabilized zirconia appeared to be a valid alternative to metal-alloys and titanium, with comparable mechanical properties and even better interaction with bone and soft tissues. The improvement of monolithic CAD/CAM manufacturing allows for a reliable, predictable, and rapid workflow that can correspond to a holistic treatment philosophy associated with zirconia fixtures. This reported clinical case highlights the advantages of this approach in resolving particularly functionally and aesthetically complex situations. A 40-year-old patient with permanent canine impaction and the persistence of a deciduous tooth compromised by caries was successfully rehabilitated with the surgical removal of the enclosed tooth, the seating of a mono-phase zirconia implant after the deciduous extraction and its loading with a zirconia single crown, without any clinical or radiographical alteration up to seven years follow-up.


Assuntos
Desenho Assistido por Computador , Zircônio , Adulto , Coroas , Humanos , Tecnologia
14.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 39(4): 386-397, 2021 Aug 01.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-34409793

RESUMO

The correct implant site design and placement are the basic clinical techniques that must be known for implant restoration. For a long time, most implants have been placed by free hands, and the choice of site is mostly dependent on the accumulation of long-term experience of the surgeon. The selection of implant site guided by this experience analogy logic is often based on the surgeon's level of experience,which often makes it very easy to produce complications related to the implant restoration of the incorrect site. In contrast, a clinical program using digital guidance and real-time measurable verification has emerged based on the restoration-oriented implantation concept, which marks the formation of an accurate, measurable and verifiable whole-process digital implant prototype. Furthermore, from the perspective of surveying, the numerical requirements that digital implant restoration relies on are actually incomplete to the four elements of measurement, which leading to the doubts about its authenticity. This article will question the numbers in implant restoration, and conduct a preliminary demonstration, and propose a new reliable actual measurement and verification method of the correct location and the numerical requirements of the restoration space and a new clinical program that relies on numbers from the perspective of the evolution of digital restoration, guided implantology and actual measurement technology. And this article further discusses the current mainstream implant restoration technology based on experience analogy which cannot effectively support the whole process of digital implant restoration and provides a new logical cognitive basis for the final realization of the entire process of digital implant restoration.


Assuntos
Implantes Dentários , Prostodontia , Desenho Assistido por Computador , Implantação Dentária Endo-Óssea , Humanos
15.
Medicina (Kaunas) ; 57(8)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34440981

RESUMO

Background and Objectives: Ceramic veneers represent the most appropriate treatment option for minimally invasive aesthetic rehabilitation. For long-term clinical success, the accurate marginal and internal adaptation of dental restorations are of paramount importance. The aim of this in vitro study is to assess the effect of a novel (patented) design of veneers compared to conventional ones on their marginal and internal gap to the prepared tooth surface. Materials and Methods: Twenty-four lithium disilicate ceramic veneers are obtained using Computer-Aided-Design (CAD) and then milled using Computer-Aided-Manufacturing (CAM). The samples are divided into two groups: 12 conventional (CO) veneers (i.e., with a linear marginal contour) and 12 crenelated (CR) veneers, the latter with the novel sinusoidal marginal design. All samples are bonded to frontal teeth, and the adhesive interfaces are analyzed using two methods, optical microscopy and micro-Computed Tomography (CT): the former for the accuracy of the marginal gap and the latter for the internal gap (as well as for the homogeneity of the luting cement) of ceramic veneers. Results: STATA and one-way ANOVA tests reveal significant differences between CO and CR veneers: (i) the marginal gap is smaller for CR (64 µm) than for CO veneers (236 µm); (ii) the internal adaptation is better for CR veneers: for a cement width of up to 120 µm, the covered surface for the CR group is 81.5%, while for the CO group it is 64.5%; (iii) the mean of the porosities within the cement is not significantly different (3.4·106 µm3 for CO and 3.9·106 µm3 for CR veneers), with a higher standard deviation for the CO group. Analytical modeling is achieved for internal gaps using the micro-CT results. The characteristic functions obtained allow us to compare the volume of luting cement for the two types of veneers. Conclusion: The novel veneers design produces an improvement in the marginal and internal adaptation of the restorations to the prepared tooth surface. Thus, it provides favorable premises for better clinical performances.


Assuntos
Cerâmica , Microscopia , Desenho Assistido por Computador , Humanos , Teste de Materiais , Microtomografia por Raio-X
16.
BMC Oral Health ; 21(1): 335, 2021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-34233683

RESUMO

BACKGROUND: Conventional static computer-assisted implant surgery (s-CAIS) requires special equipment, such as 3D printers or computer numerical control (CNC) lathes. We present a low-cost workflow for manufacturing dental implant guides based on tetrahedron positioning technology (TPT). The aim of this case report was to use a surgical guide technique for dental implant placement using tetrahedron positioning technology. CASE PRESENTATION: A 28-year-old man consulted for the treatment of a missing right first mandibular molar by implant placement. The cone-beam computed tomography (CBCT) data were imported into medical image processing software for analysis, and the implant design was simulated. The implant design on CBCT was transferred to the mandibular model using TPT, and the implant surgical guide was made to guide the dental implant operation. CBCT was performed postoperatively and compared with the preoperative design to check the accuracy. The central deviation of the implant head was 0.31 mm, the central deviation of the implant apex was 0.93 mm, and the implant angular deviation was 2.45°. CONCLUSION: The use of tetrahedral positioning technology based on CBCT data is a new method for making implant guides. It is a promising technique offering a highly predictable outcome and lower risk of iatrogenic damage. However, these results should be interpreted with care since they are based on limited evidence from a case report. Larger population studies with longer follow-up periods and standardized experimental studies are required.


Assuntos
Implantes Dentários , Adulto , Desenho Assistido por Computador , Tomografia Computadorizada de Feixe Cônico , Implantação Dentária Endo-Óssea , Humanos , Imageamento Tridimensional , Masculino , Tecnologia
17.
Clin Oral Implants Res ; 32(9): 1097-1104, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34218450

RESUMO

PURPOSE: The study aims to evaluate the effect of tooth position, sleeve height, supporting length, resin E-modulus, and manufacturing method on the accuracy of dental implants placed in vitro fully guided in a lower jaw free-end situation. MATERIAL AND METHODS: Using resin clones of a patient case providing a free-end situation 384 implants has been experimentally placed guided. The accuracy of postoperative implant position analyzed depending on the tooth position (first and second molar), sleeve height (2 and 6mm), supporting length (tooth no. 37-33 and 37 43), resin E-modulus (<2,000, >2,000, and >3,000 MPa), and manufacturing method (milled, printed). To determine the three-dimensional accuracy angular deviation, mean crestal, apical deviation, and the linear vertical deviation at apex were calculated separately for each group (n = 12). RESULTS: The accuracy of implant placement using milled guides was affected only by the tooth position, indicating stronger deviation of implants replacing second molars than first molars. Considering printed guides, the implant position was influenced by tooth position, sleeve height, and supporting length. Linear vertical deviation >1 mm was found for printed materials with the lowest E-modulus at tooth position no. 37. Logistic regression analysis revealed a significant lower odds for linear vertical deviation >1 mm for materials with higher E-modulus (OR: 0.04; 95% CI:0.01-0.97; p = .048) and higher ratio for smaller sleeve height (OR: 2.77; 95% CI:1.20-6.38; p = .017). CONCLUSION: Accuracy of implant placement in a free-end situation lacking distal tooth support is superior for milled as compared to 3D-printed surgical guides. When using 3D-printed surgical guides, smaller sleeve heights and extended tooth support improve the accuracy of implant placement.


Assuntos
Implantes Dentários , Cirurgia Assistida por Computador , Desenho Assistido por Computador , Tomografia Computadorizada de Feixe Cônico , Implantação Dentária Endo-Óssea , Humanos , Imageamento Tridimensional
18.
Int Immunopharmacol ; 98: 107831, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34247016

RESUMO

Explicit hindrance and blockade of the viral RNA-dependent RNA polymerase (RdRp) of SARS-CoV-2 is considered one of the most promising and efficient approaches for developing highly potent remedies for COVID-19. However, almost all of the reported viral RdRp inhibitors (either repurposed or new antiviral drugs) lack specific selectivity against the novel coronaviral RdRp and still at a beginning phase of advancement. Herein, I discovered and introduce a new pyrazine derivative, (E)-N-(4-cyanobenzylidene)-6-fluoro-3-hydroxypyrazine-2-carboxamide (cyanorona-20), as the first potent SARS-CoV-2 RdRp inhibitor with very high selectivity (209- and 45-fold more potent than favipiravir and remdesivir, respectively). This promising selective specific anti-COVID-19 compound is also deemed to be the first distinctive derivative of favipiravir. Cyanorona-20, the unprecedented nucleoside/nucleotide analog, was designed, synthesized, characterized, computationally studied, and biologically evaluated for its anti-COVID-19 actions (through a precise in vitro anti-COVID-19 assay). The results of the biological assay displayed that cyanorona-20 surprisingly exhibited very high and largely significant anti-COVID-19 activities (anti-SARS-CoV-2 EC50 = 0.45 µM), and, in addition, it could be also a very promising guide and lead compound for the design and synthesis of new anti-SARS-CoV-2 and anti-COVID-19 agents through structural modifications and further computational studies. Further appraisal for the improvement of cyanorona-20 medication is a prerequisite requirement in the coming days. In a word, the ascent of the second member (cyanorona-20 "Corona Antidote") of the novel and promising class of anti-COVID-19 pyrazine derivatives would drastically make a medical uprising in the pharmacotherapeutic treatment regimens and protocols of the recently-emerged SARS-CoV-2 infection and its accompanying COVID-19.


Assuntos
Antivirais/farmacologia , COVID-19/tratamento farmacológico , Inibidores Enzimáticos/farmacologia , RNA Polimerase Dependente de RNA/antagonistas & inibidores , SARS-CoV-2/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Antivirais/síntese química , COVID-19/diagnóstico , COVID-19/virologia , Desenho Assistido por Computador , Desenho de Fármacos , Inibidores Enzimáticos/síntese química , Interações Hospedeiro-Patógeno , Humanos , Simulação de Acoplamento Molecular , Estrutura Molecular , Terapia de Alvo Molecular , RNA Polimerase Dependente de RNA/metabolismo , SARS-CoV-2/enzimologia , SARS-CoV-2/crescimento & desenvolvimento , Relação Estrutura-Atividade
19.
Clin Implant Dent Relat Res ; 23(4): 635-643, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34288341

RESUMO

BACKGROUND: Different designs of surgical drilling systems have been developed for the purpose of static Computer-Assisted Implant Surgery (sCAIS), but there is at present little understanding of how design principles affect the accuracy of implant placement. PURPOSE: The aim of this in vitro study was to compare the accuracy of implant placement among five drilling systems of sCAIS in a controlled experimental setting. MATERIALS AND METHODS: Twenty-five 3D printed models with two edentulous bilateral premolar spaces were allocated to five different drilling systems: group A: sleeve-in-sleeve, group B: sleeve-in-sleeve with self-locking, group C: mounted sleeve-on-drill, group D: integrated sleeve-on-drill with metal sleeve in the guide, group E: integrated sleeve-on-drill without metal sleeve. Models were scanned with CBCT and optical scanner. All implants were digitally planned and 10 implants placed with sCAIS in each group. Postoperative 3D deviation of placed vs planned position was measured by means of platform, apex and angular deviation. Data was analyzed using Kruskal-Wallis test (P ≤ .05). Pairwise comparisons were tested with Dunn's test with adjusted P values. RESULTS: The overall platform deviation ranged from 0.42 ± 0.12 mm (group B) to 1.18 ± 0.19 mm (group C). The overall apex deviation ranged from 0.76 ± 0.22 mm (group B) to 1.95 ± 0.48 mm (group D). The overall angular deviation ranged from 2.50 ± 0.89 degree (group B) to 5.30 ± 1.04 degree (group E). Group A and B showed significantly less angular deviation than groups D and E (P < .05). There was no statistically significant differences in all parameters between group A and B, as well as between group D and E (P > .05). CONCLUSIONS: Significant differences were found with regards to accuracy among the five sCAIS systems tested, suggesting that the drilling protocol, the devices used and the design principles of the guides could influence the accuracy of implant placement.


Assuntos
Implantes Dentários , Cirurgia Assistida por Computador , Desenho Assistido por Computador , Computadores , Tomografia Computadorizada de Feixe Cônico , Implantação Dentária Endo-Óssea , Imageamento Tridimensional
20.
J Biol Regul Homeost Agents ; 35(3 Suppl. 1): 19-28, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34289661

RESUMO

The purpose of this work was to assess the discomfort perceived by the patient during the intraoral scan procedure using the iTero Scanner. A sample of 33 patients was selected on the basis of parameters that identify a complete dentition. All treated patients underwent a traditional polyvinylsiloxane impression with double procedure and an intraoral scan in the same session. Subsequently they were given a questionnaire concerning the discomfort perceived by both procedures. Once the completed questionnaires were obtained, preliminary statistical tests were carried out to check if the distribution of scores assigned by patients to the two procedures differed significantly from a Gaussian distribution. Furthermore, the discomfort/preference indexes for the two procedures were compared using the Wilcoxon test for paired data. Finally, the Spearman correlation test was used. From the results of the preliminary normality tests, it was decided to use nonparametric type tests that gives the intraoral scan procedure more favorable scores relative to a minor discomfort. The use of intraoral scanning and more specifically of the iTero 2.9 scanner (despite a not small wand), represents an option largely preferred by patients in terms of reduction of discomfort and classic discomfort related to relief systems traditional imprint.


Assuntos
Desenho Assistido por Computador , Procedimentos Cirúrgicos Reconstrutivos , Técnica de Moldagem Odontológica , Modelos Dentários , Humanos , Imageamento Tridimensional , Percepção , Inquéritos e Questionários
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