Esthetic Rehabilitation Through CAD/CAM Technology - Case Report.

With the progress of dental materials and techniques, CAD/CAM system currently allows the manufacture of high precision prosthetic restorations. Zirconia is an ideal base for porcelain because the bonding process between the zirconia and the porcelain is stronger than it is with porcelain and metal. This means that the porcelain is less likely to fracture away from a zirconia base. Zirconia can also be colored to match teeth and it is translucent, mimicking the natural look of teeth far better than any crown with a metal base could. The aim of this article is to describe a case of oral rehabilitation, involving CAD/ CAM technology for full dental crowns, using zirconia as framework.

[Factors involved in microbial colonization of acrylic resins]. / Factori implicati în colonizarea microbiana a rasinilor acrilice.

UNLABELLED: The objective of this study was to evaluate the effect of polishing technique and the polymerisation type on the microbial colonization of acrylic resins. MATERIAL AND METHODS: The studied resins were: Castapress/Vertex, Prothyl Hot/Zermack, Duracryl Plus/Spofa Dental, Vertex-Soft/Vertex, Superacryl Plus/Spofa Dental. Ten specimens, two for every resin, presenting dimensions of 50/25/2 cm were done. One sample of each resin was polished with extrahard tungsten carbide burs, the other sample being polished with extrahard extrafine and diamond burs. The final polishing was done using a conventional method: pumice, water and lathe bristle brush for 90 seconds, 1500 rpm and soft leather polishing wheel for 90 seconds, 3000 rpm. One sample of Duracryl Plus was glazed after polishing with Glaze/Bosworth. Vertex Soft specimens were not polished because it is a resilient material. The samples were immersed in human saliva for 24 hours and after that were colored with May Grunwald Giemsa (MGG). The total germs number (TGN) was determined by Buiuc method. RESULTS: The lowest value of the microbial colonization was related to the heat-curing resins treated by conventional polishing combined with glazing techniques. CONCLUSIONS: The results noticed that the type of acrylic resin (autopolymerizing and heat-cured) and the polishing techniques have a significant influence on the microbial colonization. Specimens of self curing resin had a higher porosity than heat curing resin after the same surface treatment, generating a higher TGN.

[Surface characteristics of the acrylic resins according to the polishing methods]. / Studiu privind starea de suprafata a rasinilor acrilice în raport cu metodele de prelucrare mecanica.

AIM: The objective of this study was to evaluate the effect of the polishing technique and glazing on the porosity of the dental resins. MATERIAL AND METHODS: The studied resins were: Castapress/Vertex, Prothyl Hot/Zermack, Rapid Simplified/Vertex, Duracryl Plus/Spofa Dental, Vertex-Soft/Vertex, Superacryl Plus/Spofa Dental. Thirty specimens, five for every resin, of 50/25/2 cm in size were done. One surface of each sample was polished with extrahard tungsten carbide burs, the other surface being polished with extrahard extrafine and diamond burs. The final polishing was done using a conventional method: pumice, water and lathe bristle brush for 90 seconds, 1500 rpm and soft leather polishing wheel for 90 seconds, 3000 rpm. Twenty surfaces were glazed after polishing with Glaze/Bosworth. Vertex Soft specimens were not polished because this is a resilient material. Surface porosity of the acrylic resin specimens was measured by optical microscopy. RESULTS: The lowest porosity was obtained by conventional polishing combined with glazing techniques. No differences between glazed and non/glazed self-curing resin specimens were noticed, but there were differences between self-curing and heat-curing resins. CONCLUSIONS: Conventional lathe polishing method is an effective and reliable technique for polishing dental resins. Specimens of self-curing resin had a higher porosity than heat curing resin following the same surface treatment. Higher surface smoothness was obtained by conventional lathe polishing completed by glazing.

[Resilient attachments--biological treatment solution for unilateral partials]. / Sistemele disjunctoare--varianta biologica de tratament in edentatia partiala intinsa.

The attachments recommended for a unilateral free-end distal extension partial denture assure the comfort for the patient because don't need a cross arch stabilization. One of the most used resilient attachment is represented by FM Hinge (New Anchorvis), an extracoronal, hinge resilient distal extension attachment. It is formed by two elements: a metallic female, designed for adhering into the framework of the denture base and a male, made of fully combustible plastic high fusing for casting to precious and semiprecious alloys. The retention of the denture is due to the friction achieved through the male and female elements. The attachment should also be resilient to transfer stress to the ridge and away from the abutment teeth. Resilient attachments represent a functional, aesthetic and biological solution in unilateral extended edentation.

[Study concerning the influence of the casting parameters of dental alloys on the cast prosthetic rehabilitation]. / Studiu privind influenta parametrilor turnarii aliajelor dentare asupra pieselor protetice metalice.

UNLABELLED: The integration of a cast rehabilitation into the oral environment and its clinical longevity are mainly determined by the accuracy reproduction of the technological parameters. The aim of this study was to evaluate the structural defects induced by the modification of the technological conditions of casting the conventional and titanium alloys. MATERIAL AND METHOD: We used 35 cast prosthetic rehabilitation, divided into 7 groups. For each group we modified one parameter: the width of the wax pattern, the design and topography of the casting channels, the absence of the cleanliness of the wax pattern, the preparation of the investment material, the thermal system for the mold preparation and reduced quantity of metal used for casting. For the 7-th group, represented by titanium cast rehabilitation, we modified the design and dimensions of the casting channels. RESULTS: The changes in the technological conditions induced porosity, incomplete frameworks or plus on the prosthetic appliances. The fundamental theoretical knowledge of the clinician and dental technician and the strictly application of the technologies assure the premises of the satisfaction of the patient.

Aesthetic goals in porcelain fused to metal prosthetic appliances.

UNLABELLED: The ultimate goal for ceramic fused to metal restoration is the creation of a perfect aesthetic integration of the restoration with healthy tissues. MATERIAL AND METHOD: The study included a group of twenty-one patients. Sixteen of them were partial edentulous patients and five presented dental lesions or chromatic modifications of the dental tissues. The treatment plan consisted of metal-ceramic crowns and bridges. The ceramic system used was Vintage Halo (Shofu). RESULTS: According to the patient's age, topography of the missing teeth or colour modification, we surveyed the aesthetic rehabilitation, creating the specific morphological elements, in order to realise an individual natural aspect with a similar optical behaviour as the dental enamel. CONCLUSIONS: The current popularity of metal-ceramic restorations is primarily related to their predictable strength and reasonable aesthetics. The main parameters that are responsible for a high-quality result are represented by: non-invasive and reversible procedures, conservative preparations, individual function offered by an individualized reconstruction, gnathology-based concepts into the occlusal rehabilitation, biocompatible materials, longevity of the reconstruction and comfort for the patient.

[A maxillary premolar reconstruction with a glass fiber reinforced post]. / Reconstituire corono-radiculara cu pivot armat cu fibre de sticla. Caz clinic.

This paper presents the case of a 37 years old female patient who needed a reconstruction of an endodontic treated' second maxillary premolar. The patient presented large areas of occlusal abrasion caused by bruxism, therefore the solution consisted of a reconstruction with a non-metallic post reinforced with glass fibers. In such cases, the excessive occlusal forces developed by bruxism can produce a radicular fracture if the tooth would be reconstructed with a rigid metallic post. The glass-fiber reinforced post has some important qualities, which render it more suitable in most clinical cases: it is easy to use; has the ability to bond with restorative resins; decreases the risk of tooth fracture and provides better esthetics.

[Analysis on the stress induced by non metallic posts in dental and periodontal support by using the finite element method]. / Analiza stresului indus de pivoturile nemetalice în suportul dento-parodontal prin metoda elementului finit.

AIM: The determination of the influence of non-metallic posts on the stress distribution to the supporting tissues. METHOD: Two 3D models were created: one intact maxillary incisor and one reconstructed with post (ceramic, carbon fiber and glass fiber). The compressive load (30daN) was applied to an angle of 45 degrees on the palatal surface of the crown. The Algor software computed the stress for each model comparing the maximum registered intensity, localization and concentration into the dento-periodontal complex. RESULTS: The fiber reinforced posts induced lower stress peak inside the root, the von Mises stress in the teeth reconstructed with carbon and glass fiber post being similar to that recorded in a tooth without post. The ceramic post produced the greatest stress concentration in the middle third of the root, this behavior supporting the potential risk of the vertical root fractures registered "in vivo". CONCLUSIONS: The fiber reinforced posts are more suitable for the clinical longevity of the tooth, representing the best choice to reconstruct an endodontically treated tooth.

Morphological changes in dental pulp after the teeth preparation procedure.

The aim of this study was to evaluate the immediate changes in the pulp-dentin complex that result from crown preparation, and their correlation with the thickness of remaining dentin and the preparation technique (with or without water spray cooling). Thirty upper intact premolars scheduled for extraction for orthodontic reasons were high speed prepared, extracted immediately after preparation and divided in 5 groups. The analysis of the pulp morphology demonstrated that there are several differences according with the preparation technique. The most severe changes appear after the profound preparation without water-cooling, the odontoblastic layer being extremely affected. Also, vascular reactions and inflammatory infiltrate (in the absence of bacteria) were present. Our study revealed that the histologic changes in the pulp and dentin following complete crown preparation occur anyway and they are considered difficult to avoid, even if an adequate technique of preparation is used.

[Prevention of root fracture using posts reinforced with fiberglass]. / Prevenirea fracturilor radiculare cu ajutorul pivoturilor armate cu fibre de sticla.

(The aim of this study was to evaluate the fracture strength and mode of failure of endodontically treated teeth reconstructed with glass fiber reinforced posts. Twenty maxillary central incisors, extracted for periodontal reasons, were divided in 2 groups: gr. 1 - glass fiber posts, and gr.2 - control (endodontically treated but without posts). All samples were embedded in resin bloks and mounted in stainless steel cylinders for the compressive test. The force was applied on oral surface of the crown, until the failure occurred. The compressive loads at failure were recorded and compared with the statistical method Student t. The mode of failure of the specimens were also evaluated. The statistical analysis of the force values showed no significant difference between the groups. In conclusion, because of their low Young's modulus, the non-metallic posts made of resin composite reinforced with glass fibers have a protective effect on the dental tissues, the recorded mode of failure being very similar with the control group.

[Coronal restoration with all ceramic inlay]. / Restaurarea coronara prin inlay integral ceramic.

We present a 29 years old female patient treated with an all ceramic inlay. The IPS Empress system has been used to make an optimal, esthetic and morpho-functional restoration. An inlay restoration is a biological prosthetic solution that is indicated as a proper treatment possibility for the young patients. The IPS Empress inlays are characterized by a good biomechanical behavior, law abrasion rate and perfect chromatic integration.

[Dento-stomato-facial rehabilitation of young patients. Practical alternatives]. / Alternative practice de reabilitare dento-somato-faciala la tineri.

The design conception and the technological achievement of every gnato-prosthetic device are conditioned by a minute evaluation of the biological and morphological individualities of each case, the social level of the patient, corroborated with the technological supply. In our study we evaluated different modalities of dento-stomato-facial rehabilitation of young patients with partially reduced maxillary or mandibular dentition. The study was carried out on a group of 12 young patients, 5 males and 7 females, aged between 16-24 years, who presented at the clinic for the treatment of complex functional disorders that occurred as a consequence of the dentition. The fixed mixed gnatoprosthetic therapy for the young patients and teenagers has to be adapted to the surveyed clinical individuality. The success of the therapy is assured by the accurate application of the gnatoprosthetic principles, the accurate achievement of the technological steps, the use of compatible biomaterials according to the dento-stomato-facial features of this age category.

[Preventing methods of prosthetic stomathopaties concerning patients with partial removable prosthesis]. / Metode de prevenire a stomatopatiilor protetice la pacientii protezati adjunct.

Partial removable prosthesis is the most frequently therapeutical solution applied to patients aged more than forty years and which were diagnosed with extended partial edentations. The purpose of our study is to estimate oral tissues diseases installment to subjects having partial removable prosthesis, this patients being exposed on contacting stomatopaties. We developed this study on the clinical examination of a group of forty subjects partial removable prostheded, three or four year ago, respectively 23 woman and 17 men aged between 40 and 75 years. The oral hygiene, caries incidence, clasps fractures were evaluated, it was registered the aspect of the acrylic resin of the base, and also the inflammation degrees of the oral mucousa. A high level of oral hygiene statement diminuates the installment of the whole series of post-prothetical involvements, also decreasing the stomatopathies appearance frequently.