Effect of mechanical and chemical preparation of Artificial and Acrylate prosthetic base

Introduction: Preparation of the basal area in acrylate artificial teeth is a very important factor in the quality of a dental prosthesis. It refers to the link between artificial teeth and acrylic denture base made of heat polymerized acrylic. The most common reason for failure of mobile prosthetic works is falling artificial teeth acrylate prosthetic base. The failure is due to the manner of connection between the base and artificial teeth. As the main factor which affects the level of retention is mechanical preparation of the basal area in acrylate teeth. Materials and Methods: For realization of the setted aim 10 acrylic models were analysed. The research was designed to show the justification for the mechanical and chemical preparation of the basal area in acrylate artificial teeth, then using a light microscope to measure the size of the crack between acrylic artificial teeth and acrylic denture base. The research described two different techniques, the first one with chemical preparation and the second one with mechanical and chemical preparation, which justify the best technique of preparation. Results: The results showed that there is no distance to the interspace occurs in models from the first and the second group. For the models of second group interspace between artificial teeth and acrylic base have bgger contact area, so there is better connection. Conclusion: Combination of mechanical and chemical preparation of artificial teeth significantly affect the degree of physical connection and also provides greater contact surface with acrylate prosthetic base. Keywords: arteficial teeth connection, heat polymerization, mechanical preparation, chemical preparation

Циркониум керамика за современи дентални надоместоци

Стоматологија како научна и професионална дисциплина се развива од ден на ден и во голема мера допринесува за развојот на стоматолошките материјали и нивната технологија. Компјутерската технологија станува дел од секојдневниот живот на современиот човек, а со тоа истата неминовно станува дел и од денталната медицина. Следејќи ги светските трендови во денталната реконструктивна протетика која се занимава и со изработка на фиксни протетски надоместоци, слободно може да кажеме дека сегашноста и блиската иднина му отстапува место на циркониумот, кој се повеќе ја истиснува метал-керамиката

Effect of mechanical and chemical preparation of Artificial and Acrylate prosthetic base

Introduction: Preparation of the basal area in acrylate artificial teeth is a very important factor in the quality of a dental prosthesis. It refers to the link between artificial teeth and acrylic denture base made of heat polymerized acrylic. The most common reason for failure of mobile prosthetic works is falling artificial teeth acrylate prosthetic base. The failure is due to the manner of connection between the base and artificial teeth. As the main factor which affects the level of retention is mechanical preparation of the basal area in acrylate teeth. Materials and Methods: For realization of the setted aim 10 acrylic models were analysed. The research was designed to show the justification for the mechanical and chemical preparation of the basal area in acrylate artificial teeth, then using a light microscope to measure the size of the crack between acrylic artificial teeth and acrylic denture base. The research described two different techniques, the first one with chemical preparation and the second one with mechanical and chemical preparation, which justify the best technique of preparation. Results: The results showed that there is no distance to the interspace occurs in models from the first and the second group. For the models of second group interspace between artificial teeth and acrylic base have bgger contact area, so there is better connection. Conclusion: Combination of mechanical and chemical preparation of artificial teeth significantly affect the degree of physical connection and also provides greater contact surface with acrylate prosthetic base. Keywords: arteficial teeth connection, heat polymerization, mechanical preparation, chemical preparation

Approximal margin adaptation on class II – posterior interproximal cavity restored with open and closed sandwich technique

The sandwich technique is used for restoring class II caries where glass-ionomer cement is used as a liner under some composite restorations. There are two variations of the sandwich technique, the open sandwich and the closed sandwich technique. The open sandwich technique involves the placement of glass ionomer cement into the base of a proximal cavity and filling the preparation with glass ionomer up to the level of the dento-enamel junction. The final portion of the restoration is placed with composite resin to provide wear resistance and aesthetics on the occlusal surface. The closed sandwich technique involves placing the glass ionomer at the base of the proximal box so as it falls just short of the external cavo surface. After setting, the glass ionomer is etched and a dentine bonding agent is applied before placing a composite resin into the proximal box and occlusal surface, leaving the glass ionomer cement encased within the preparation. In this study we will test the approximal margin adaptation on teeth restored using both open and closed sandwich techniques. On 30 extracted teeth we prepared class II cavities where 15 of them were restored using the closed and 15 using the open sandwich technique. The teeth around the margins of the restoration (the crown and root) were then isolated using varnish which is not permeable for methylene blue, then they were placed in a solution of methylene blue to check the micropermeability of the margins. In that solution the teeth were kept seven days and after that they were cut in longitudinal sections. Under microscope we checked the marginal adaptation of the teeth restored using closed and open sandwich technique i.e. if the margins on the longitudinal section were colored in blue. All the teeth in our study had a very good marginal adaptation, no significant differences were found in the teeth restored using the open sandwich technique and closed sandwich technique. Because of the properties of the glass ionomer cement, as listed in various 52 literature: (1) the glass-ionomer material bonds both to the tooth structure and the composite, thereby increasing retention form; (2) fluoride contained in the glass-ionomer material reduces the potential for recurrent caries; and (3) the glass-ionomer material, because of its bond to tooth structure, provides a better seal when used at non-enamel margins; the marginal adaptation was very good on our test subjects, which implies that in clinical use these techniques may provide a good alternative for restorations to minimize the chances of seconder caries formation. Keywords: class II restoration, closed sandwich technique, marginal adaptation, open sandwich technique

Значење на оклузалната морфологија при артикулација

Цел: Цел на нашиот труд беше да постигнеме идеална функционална оклузална морфологија и интеркуспидација при моделација на оклузалните површини на бочни заби во горна и долна вилица. Материјал и метод: за реалзација на поставената цел го применивме оклузалниот компас според Douglass De Vreught кој овозможува и ја олеснува моделацијата на функционалната оклузална површина преку различно обоени полиња (букалните тубери на долни и горни бочни заби за време на мастикацијата - назад до центрична оклузија и за време на парафункционалните движења - надвор од оклузија). Со помош на оваа алатка беа измоделирани во восок 10 молари (пет горни и пет долни). Во трудот ќе бидат прикажани етапно фазите на работа. Резултати: Со примена на Douglass De Vreugd оклузалниот компас се постигна следново: кога беше поставен во дисталниот централен стоп сите површини кои припаѓа во обоените секции беа ослободени од интерференции со крајна цел да обезбедат спротивните тубери да патуваат во и од централна оклузија. Заклучок: Интердисциплинарната стручна соработка на стоматолозите и забните техничари се неопходни во имплементацијата на овој оклузален компас како современа алатка која ја олеснува и ја подобрува функционалната оклузална морфологија на идната фикснопротетска конструкциј

3D Printing in Dental Lab

Researchers all over the world are very busy developing 3D printers that we will be able to use for many applications and (for now) in unimaginable ways. With the speed of developing increasing at an exponential rate, those developments are seemingly around the corner. In the dental technology world, engineers are coming close developing a 3D printer that will be able to print a complete denture, including both the resin base and the teeth. There is a lot to be excited about in the dental industry.It is considered a rapid technology because it eliminates several laborious steps used in conventional dental technology techniques and it takes nearly the same amount of time to produce one object or many. Therefore, its efficiency is enhanced by printing multiple units and relying upon the economies of scale. The objects the printer can produce for the laboratory include models (casts), crown and bridge resin burnout patterns for casting or pressing ceramics, temporary crowns, surgical guides, splints, partial denture framework patterns, custom impression trays, and more. With proper settings, it can consistently produce resin products of stunning accuracy and detail, especially when compared with subtractive milling technology. Conventional dental technology is subject to a high degree of inaccuracy, costly labor, and even more expensive materials. Making these objects not only requires a considerable amount of time, but also a highly skilled technician with a complete understanding of the process. And, last but not least, researchers at Wake Forest University in North Carolina say they have created a 3D printer that can produce organs, tissues, and bones that could theoretically be implanted into living humans. Using some of the same methods we are using to print today these researchers are laying down layers of human cells. They have printed out an ear-shaped piece of cartilage, a muscle, and a piece of a jawbone. BioPrinting is truly ground breaking. We may be a few years from printing the final restoration and even farther than that from printing a replacement jaw, but as the above research suggests we may be there sooner than we think. Keywords 3D printers, CAD design, digital dental technology, bio print

Digital technology and techniques used in the fabrication of complete dentures

Digital denture is a complete manufacturing process for the rapid production of removable full-arch dentures. Exclusive design software and ideally coordinated materials, combined with well-designed manufacturing strategies and milling equipment platform, provide predictable and reproducible results. The material for digitally produced, are tooth coloured discs made from acrylic material, which are suitable for the individual design and production of whole tooth segment. The long-lasting dental restorations are individually customized to integrate with patients natural antagonist teeth Base material are PMMA discs for the production of denture bases. The PMMA material is distinguished by its high impact quality. This enhances the fracture strength and increases the longevity of the restoration. In addition, the industrial manufacturing process ensures homogeneous material quality. In the first milling procedure, the dental arch is milled occlusally with oversized dimensions. The basal surfaces, however, are milled exactly to their final dimension, so that the denture base fits perfectly. The oversized dental arch is adhesively cemented to the denture base. Cementation is a quick and easy procedure for the dental technician. During the fine milling process, the dental arch is milled to its final size and the excess bonder is removed. With digital denture, the new digital manufacturing process for dentures, you save valuable time compared to manual production methods: less manual working steps, less interruptions in production, no complex plaster models and no articulating. As a result, porosities and air inclusions in the material can be avoided, which results in a high-quality denture base. Keywords Digital denture, CAD design, PMMA discs, prosthetic

Comparison between CAD-CAM and hot-press lithium disilicate crowns

Hot-pressing and computer-aided design and computer-aided manufacturing (CAD-CAM) are major techniques for the fabrication of lithium disilicate crowns. They exhibit different accuracies regarding marginal fit, an important factor in restoration survival. However, studies comparing the marginal fit of different fabrication methods are lacking. Purpose: The purpose of this in vitro study was to compare the marginal discrepancy (MD) and absolute marginal discrepancy (AMD) of lithium disilicate crowns produced by the hot-press and CAD-CAM techniques. Meterial and methods: Thirty typodont teeth were divided into 2 groups. Fifteen teeth were scanned with the CEREC Omnicam intraoral scanner, and crowns were fabricated with the CEREC MC XL chairside CAD-CAM milling unit from IPS e.max CAD blocks. Fifteen typodont teeth were sent to a dental laboratory, and lithium disilicate crowns were fabricated from IPS e.max press ingots using the hot-press technique. The 30 crowns were cemented and then sectioned with a precision saw. The MD and AMD were measured for each crown with a light microscope. One-way ANOVA was conducted to analyze significant differences in crown marginal fit between the fabrication systems (α=.05). Results: For the CAD-CAM technique, the mean values of the AMD measurements were 115 μm, and for the hot-press technique, 130 μm. The MD measurements were 87 μm for the CAD-CAM technique and 90 μm for the hot-press technique. Conclusons: No significant differences were found between the fabrication methods tested. Both the CAD-CAM and hotpress techniques for producing monolithic lithium disilicate crowns produced MD values of less than 120 μm, within the clinically acceptable range

CAD/desing and types of aestethic layerng zirconia

Introduction: Zirconium restorations are put in place to achieve a better aesthetic appearance that over the years aesthetically does not satisfy or if there is a shortage of certain teeth to compensate for the space. Aim: To present the method of making full-featured zirconia and the construction of a vestibular cut-back modeling technique through a CAD / Design system with complete anatomy-morphological features. The aim is to make a comparison between these two techniques. Material and method: The 3Shape program is one of the programs used to design bridges or crowns. Zirconium discs are used on which the designed bridge or crown through the CAD / Design system is operated. CAD / Design system is a system used to design the anatomo-morphological characteristics of the bridge or crown that needs to be made. After the designing, zirconium discs are used for bridge or crown modeling and they are part of the CAD / CAM system. In the case of full zirconia bridges or crowns after their cutting they are stained with paint, and in the case of cut-back zirconia, a bridge construction allows designing a certain space on the vestibular surface to place ceramics. Conclusion: These crowns or bridge are long lasting, naturally lying under the gingiva and showing successful incorporation in the oral environment. Also, zirconium crowns do not have transparency and do not differ from natural teeth, making it very difficult to see the difference between the crown and the already existing natural tooth

Анатомија на вилици и дентална морфологија - Скрипта

Пред вас се наоѓа скриптата по предметот Анатомија на вилиците и дентална морфологија, ракопис со чија што помош ќе запливате во водата на денталната медицина. Оваа скрипта ги содржи описите на сите анатомски делови на вилиците и околувиличните структури. Исто така во неа се опишани и сите морфолошки карактеристики на поедините заби. Се надеваме дека оваа скрипта ќе Ви помогне за понатомошното надрградување