Journal articles on the topic 'Teeth Dental casting'

Background : Nows a days has developed many kind of dentures to improve the functionality, comfort aesthetics. Stability, retention and its aesthetic can be improved by attachments. With many kind design assortment of dentures so need a different technique with the existing design. Purpose : The aim of this study is to know the danture manufacturing process in combination with Castable protesa Extracoronal Attachments labolatory procedure. Review: Fixed dentures are each bonded teeth protesa, inserted mechanically and support by teeth or dental implant abutment or that provide the main support for the dental protesa. A partial denture is a spin-off protesa that replaces one or more missing teeth, on the maxillary or mandibullary and can be opened by patients without the supervision of a dentist. Extracoronal attachment is an attachment that is part of the male and female part are almost entirely outside the contours of the Crown of the tooth. Conclusion: the initial stages are making of coping use wax pattern and inserted the female, the casting of metal, porcelain applications, making the wax pattern of the metal frame work, the casting of metal, inserted male, making a removable dentures.

While using casts in place of original bones and teeth for study with the SEM is a rather common practice, periodic updates and introductions of unique casting methods help to keep the process of improving cast quality cumulative, limiting unnecessary repetition of ineffectual procedures. The following is a summary of casting methods that I have synthesized from several published reports as well as some that I have developed independently (e.g., Waters and Savage 1971; Scott 1982; Rose 1983; Gordon 1984; Teaford 1991; Buikstra and Ubelaker 1994; Schmidt, 1998). The study for which I first employed these methods consisted of hundreds of archeologically- derived human teeth dating from about 1,000 to around 10,000 years ago. The study required detailed views of dental surfaces magnified 500X (Figure 1). The casts that I produced routinely had features that were distinct at magnifications of 2.000X and higher.

This article presents the results of the research on the development of the technology of increasing the service life of the sheets in the working conditions of the casting at the Central Repairs and Mechanical Plant at the Almalyk Mining and Metallurgy Refinery (CPC). One of the factors that led to the loss of Val schisternia was the study of the appearance, rupture and dental breakdown of the working surfaces, which led to increased production costs. Analyzes have shown that thermal processing and so-called thermal processing are recommended to increase the working capacity of the plants and factories at the refineries of electrochemicals (EHP).

Dental diseases are among the most common ailments, and dentists in the United States spend over 50% of their time in dental practice rebuilding carious, malformed, and traumatically injured teeth. It is logical, therefore, that the majority of the dental school curriculum is devoted to the diagnosis, prevention, and treatment of teeth with anomalies. Dentists have several choices of materials they can use to accomplish the task of rebuilding teeth. Besides amalgam, they have ceramic materials, resin composites, base-metal and noble casting alloys, and glass-ionomer cements to use to restore the posterior dentition. Each of these restorative materials has advantages and disadvantages, and the clinical judgment as to when a particular material should be used is given a high priority in dental education. Amalgam is the most widely used of these restorative materials, with 92% of dentists listing it as the material of choice in the posterior of the mouth (Clinical Research Associates, 1990). Dentists have been placing amalgams for over 150 years in the US. They placed 150 million last year, which represents over 75 tons of amalgam alloy. The reasons that dentists use this restorative material so frequently are its durability, ease of manipulation, and low cost. Numerous clinical studies have been conducted on the serviceability of amalgam. Most of these have been on the old, low-copper alloys, and results indicate that they last from 8 to 15 years (Bailit et al,, 1979; Osborne et al., 1980; Qvist et al., 1986). In the past 20 years, vast improvements have been made in amalgams with the development of the high-copper systems. Clinical studies initiated in the 1970's are reporting that the well-placed high-copper amalgam will last over 30 years (Laswell et al., 1989; Letzel et al., 1989; Osborne and Norman, 1990; Osborne et al., 1991). The ease with which amalgam is manipulated has no equal. Placement of amalgam takes only 20-50% of the time it takes to restore a tooth with other materials. For the amalgam, this cost in placement time and the cost to purchase the material are considerably less. The one factor that amalgam does not have in its favor is esthetics. The other-restorative materials, frankly, look better.

Dental casts are invaluable research tools. There are a variety of molding compounds available, all having temperature, humidity, and timing guidelines to ensure a precise replica of dentition. However, not all field research conditions allow for adherence to environmental guidelines requiring longer wait times prior to pouring epoxy for casting. This study, tests a common molding compound in extreme environments and over varying time intervals, testing the integrity of the dental molds in producing precise replicas of original teeth. 580 molds were created under three varying environments: room temperature, hot/humid, and cold/dry. Molds were removed from these environments in two-week intervals over twelve weeks. The resulting casts were measured to determine timing limitations for producing accurate dental casts under varying environments. Molds stored at room temperature retained their shape and size for the complete twelve weeks. Molds kept in a hot and humid environment, however, only maintained their shape and size up to four weeks, whereas molds in a cold and dry environment showed significant changes by the end of the second week. These findings provide additional tools for researchers working in a variety of field conditions allowing casts to be taken of specimens that cannot be transported off site.

Background: Metal frame denture design is common used for partially dentate patient, one of the problem was a metal appearance from wrought wire or a metal casting clasp as retainer, which is not really aesthetic. Telescopic overdenture with its double crown will be the best solution for those cases. Purpose: The purpose of this case report was to reported telescopic overdenture design and fabrication where the aesthetic was the main consideration. Case: Sixty years old female patient, a businesswoman, came to Dental Hospital of Universitas Airlangga, complained about her upper partially dentate and 6 years lower fixed partial denture, which is not comfortable to wear and her upper anterior teeth doesn’t look quite good. She wanted to make crowns and removable denture. Case management: After the diagnosis were made, the pretreatment plan were remove crown for the upper jaw, remove the bridges on lower jaw, and transitional dentures were made to maintain the VDO. The crowns and veneer were fabricated and inserted while the inner copings were tried up on prepared teeth. After the the dentures were produced, the inner copings were luted to the abutment teeth, and then the dentures were inserted using FGP (Friction GriP) cement for the friction effect. Discussion: Telescopic overdenture is consists of a double crown system known as “the telescopic”, the procedure involves fitting the remaining natural teeth with inner metal crowns, followed by outer crowns as part of an over denture that can be removed by the patient. Conclusion: This technique ensures that telescopic overdentures give natural aesthetic result.

Background/Aim: Dental impressions present a negative imprint of intraoral tissues of a patient which is, by pouring in gypsum, transferred extraorally on the working cast. Casting an accurate and precise working cast presents the first and very important step, since each of the following stages contributes to the overall error of the production process, which can lead to inadequately fitting dental restorations. The aim of this study was to promote and test a new model and technique for in vitro evaluation of the dental impression accuracy, as well as to asses the dimensional stability of impression material depending on the material bulk, and its effect on the accuracy of working casts. Methods. Impressions were made by the monophasic technique using the experimental master model. Custom trays with spacing of 1, 2 and 3 mm were constructed by rapid prototyping. The overall of 10 impressions were made with each custom tray. Working casts were made with gypsum type IV. Measurement of working casts was done 24 h later using a co-ordinate measuring machine. Results. The obtained results show that the working casts of all the three custom trays were in most cases significantly different in the transversal and sagittal planes in relation to the master model. The height of abutments was mainly unaffected. The degree of convergence showed certain significance in all the three custom trays, most pronounced in the tray with 3 mm spacing. Conclusion. The impression material bulk of 1?3 mm could provide accurate working casts when using the monophasic impression technique. The increase of the distance between abutment teeth influences the accuracy of working casts depending on the material bulk.

Traditionally oral appliances i.e. removable orthodontic appliances, bite splints and snoring / sleep apnea appliances are made with alginate impressions and wax registrations. Our aim was to describe the process of manufacturing customized oral appliances with a new technique i.e. rapid tooling method. The appliance should ideally be custom made to match the teeth. An orthodontic patient, scheduled for conventional orthodontic treatment, served as a study subject. After a precise clinical and radiographic examination, the approach was to digitize the patient’s dental arches and then to correct them virtually by computer. Additive manufacturing was then used to fabricate a mould for a soft customized appliance. The mould was manufactured using stereolithography from Somos ProtoGen O-XT 18420 material. Casting material for the mould to obtain the final appliance was silicone. As a result we managed to create a customized soft orthodontic appliance. Also, the accuracy of the method was found to be adequate. Two versions of the described device were manufactured: one with small and one with moderate orthodontic force. The study person also gave information on the subjective patient adaptation aspects of the oral appliance.

Introduction: Tooth crowding can cause complaints if not treated early — this condition resulting in aesthetic disorders, and also masticatory and speech function disruption. The study was aimed to determine the predisposing factors of tooth crowding in the mixed dentition period by the tooth size and dental arch width. Methods: Research type was random cross-sectional. The sample was as much as 29 children with mandibular casting; then the mandibular model cast of these 6 – 9-years old children were divided into two groups according to the crowding condition in the mandibular anterior region, and the measurement was performed afterwards. Space available category was (A/A1), mesiodistal width of mandibular incisor (B/B1), total arch length (C/C1), intercanine width (D/D1), first primary intermolar width (E/E1), second primary intermolar width (F/F1), first permanent intermolar width (G/G1), interalveolar width (H/H1). Result: The results of the t-test showed significant differences (p < 0.05) in the available space for 4 incisors, where the space was larger in the non-crowded group with a difference of 2.22 mm and the mesiodistal sizes of these 4 incisors was larger in the crowded teeth group, with the difference of 1.8 mm. The results of the Pearson correlation coefficient showed a positive relationship to several measurements, namely D to C1, E to D1 and H to B1, C1, D1, F1 and G1, with the t-value > 3 and the r-value was closer to 1, which showed a correlation with strong closeness degree (r > 0.61). Conclusion: Predisposing factors of tooth crowding in the mixed dentition period were the first intercanine width (D), first primary intermolar width (E), and alveolar arch width (H).Keywords: Tooth crowding, arch dimension, mixed dentition period.

Abstract Aim: The aim of this study was to evaluate and compare the tensile bond strength of nickel-chromium alloy to dental enamel by using four different resin cements. Materials and Methods: 40 extracted central incisor teeth embedded in acrylic blocks were flattened not to expose dentin. Wax rectangular blocks of 5 mm length, 5 mm width and 1 mm height with a loop were invested and casted using Nickel-Chromium alloy by conventional induction casting method and sandblasted. Then casted rectangular blocks and 40 tooth embedded acrylic samples were divided into four groups (10 each) and cemented to tooth enamel following manufacturer's instructions as; GroupAcemented using RelyX U200, Group B cemented using Smartcem 2, Group C cemented using Multilink Speed and Group D cemented using Multilink N and then stored in artificial saliva for 24 hours. The direct pull tensile test was carried out on Universal Testing Machine at cross head speed of 0.5mm/min. Results: One way ANOVA showed a highly statistically significant (p<.01) difference between all the four resin cements. Post Hoc Tests- Multiple comparisons showed highly statistically significant (p< 0.01) difference between RelyX U200: Multilink N, Smartcem 2: Multilink Speed, Smartcem 2: Multilink N, Multilink Speed: Multilink N. Difference between RelyX U200 : Smartcem 2 and RelyX U200 : Multilink Speed was statistically significant(p< 0.05). Conclusion: Self etch resin cement (Multilink N) showed maximum mean tensile bond strength as compared to self-adhesive resin cements (Smartcem 2, RelyX U200 and Multilink Speed). Clinically the greatest advantage of self-adhesive cements is the easy and fast application technique. But this time saving technique is not as effective as self-etch resin luting agents. The presumed benefit of saving time with self-adhesive luting agents may only be realized at the expense of compromising bond strength.

Aim: The purpose of this research was to evaluate the behavior of the system locator settings associated with distal extension removable partial denture lower (PPR) by finite element analysis (FEA).
 Materials and Methods: A Class II Kennedy 3D model using a CAD software Solid Works 2010 (SolidWorks Corp., Concord, MA, USA), and subsequently processed and analyzed by ANSYS Software version Model 14. One (1) was designed implant Tapered Screw -Vent® (ref TSVB10 Zimmer Dental-Carlsbad,CA,USA.) length x 10mm diameter 3.7mm with a 3.5mm platform, internal hexagon with its respective screw fixation; this was located at the tooth 37 as a rear pillar of a PPR, whose major connector was a lingual bar casting (alloy cobalt chromium), based combined (metal/ acrylic) with teeth to replace (37, 36 and 35). Efforts were evaluated von Mises in a 400N load. This analysis allowed assessing the performance of various prosthetic structures modeled and generated effects on bone-implant interface.
 Results: Differences between the values von Mises in all structures and loads were observed before there was no permanent deformation in any of them. Structures such as bone showed in normal values microstrain.
 Conclusions: The behavior of the PPRimplant connection, showed a favorable distribution efforts by using a PPR, subjecting it to load in the vertical direction.

Periodontitis is a local infection in the gingival crevices, which affects the structural organs surrounding the teeth like periodontal ligament, connective tissue and bone. Ornidazole is an antimicrobial drug widely used to treat periodontitis. The primary objective of this study was to design and evaluate periodontal films of ornidazole for placement into the periodontal pockets for targeted delivery of drug. Nine formulations (F1 to F9) were prepared by solvent casting method using polymer A, polymer B and plasticizer A. Chloroform and dichloromethane were used as solvent system. The API and dental films were then evaluated for various parameters including trinocular microscopic image, melting point, weight variation, thickness, folding endurance, surface pH, swelling index, percentage moisture loss, antimicrobial activity, content uniformity, in vitro drug release and release kinetics as well as RTIR and DSC. Formulation F1 showed the minimum weight and thickness and F9 showed the maximum. It was observed that weight and thickness of film were directly proportional to the total solid content of the film. RSDs of content uniformity test for all the batches were below 3.0%. Folding endurance and swelling index of films were inversely proportional to the amount of polymer in the film. The surface pH of all the batches were between 6-7. Formulation F1 revealed the maximum percentage of moisture loss (19.34%), while F8 showed the minimum (3.654%). Formulation F2 demonstrated data the highest zone of inhibition (21.91 mm).Bangladesh Pharmaceutical Journal 19(2): 133-146, 2016

Purpose Fixed structures in prosthetic dentistry are highly customized products, manufactured individually for patients who have missing teeth. When choosing the technology for fixed dental structure manufacturing, three viable options are available (precise casting, milling and selective laser melting [SLM]). All these technologies can be used to produce a dental structure from CoCr alloy. Besides materials and availability of technologies, economic efficiency is an important factor when choosing a production method. The purpose of this study is to develop an estimation model for achievable productivity of selective laser melting and compare the results with the productivity of conventional manufacturing. Design/methodology/approach Results presented in this paper are based on manufacturing time analysis of an individual case with each of the technologies mentioned above. Because of the efficiency of SLM is highly dependent on how efficiently the work space of the machine is used, this issue was also included in the research. Data used for research were acquired from practical use of each technology in dental applications. Findings Analysis of achievable SLM manufacturing speeds is based on the previous research into manufacturing speeds of additive manufacturing technologies. The presented results present a model that can be used to estimate the productivity of the SLM technology. Research limitations/implications Research was limited to a specific SLM machine type with a fixed workspace volume. Nevertheless, the results show that any SLM machine has to be used as efficiently as possible to be able to be competitive regarding the conventional manufacturing technologies. Practical implications The presented results show clearly at least a rough estimation of what kind of parts and in what volume will be manufactured with an SLM machine prior to buying one. Social implications Results can help to widen the economically efficient way of running SLM machines, replacing conventional manufacturing for medical applications especially with complicated cases. Originality/value A method is presented to adapt the estimation model to a particular real-life production scenario. This method can be used to establish how efficiently selective laser sintering can be used and if using SLM machine instead of conventional manufacturing would be economically viable.

ABSTRACT Background There are a great amount of materials and techniques to use during dental prosthesis production that may confuse the dentist at the time of choice. Material's choice should be done considering ideal chemicophysical and biological properties and high detail reproduction. Aims The present study aimed to test the influence of differents impression materials and storage times on the dimensional accuracy of casting models. Materials and methods Four elastomeric materials– polysulfide, polyether, condensation silicone and addition silicone–were used to reproduce a master model of human teeth which were prepared for metaloceramic fixed prosthodontics. Six reference points were established on each tooth in order to determine four intervals: MD–mesial-distal, BL–buccal-lingual and CO–cervical-occlusal distance from premolar, and INT– interpillar distance–from the distal surface of the premolar to the mesial surface of the molar. The impressions were stored for half, 2 and 12 hours and pondered with a type IV gypsum. Results Cast measurements data were subjected to ANOVA (4 × 3), Tukey's – α = 0.05, Kruskal-Wallis and Dunn's tests – α = 0.05. The interaction between materials and storage time presented statistically significant for VP and CO intervals. For each storage time, materials presented dimensional alteration statistically significant. Conclusion Impression materials accuracy was affected by the storage time. All materials presented different dimensional accuracy when evaluated in a same period of time. Polysulfide was the only material that presented stable behavior over the time. How to cite this article Gonçalves FS, de Freitas Oliveira W, Soares LA, Carlo HL, da Mota AS, Popoff DAV, Soares CJ. Impression Materials and Storage Time Influence on Cast Models Accuracy. Int J Experiment Dent Sci 2013;2(1):18-23.

Among the numerous techniques of oral rehabilitation, precision attachments are considered as a good treatment option in removable (RPD) as well as fixed partial dentures (FPD). Precision attachments enhance patient’s self-confidence and selfimage as they help in facilitating aesthetic, functional and retentive replacement of teeth that are missing in the oral cavity. They can improve the aesthetics by eliminating the clasp assembly in cast partial dentures (CPD). This particular case report explains the treatment sequence and approach for the utilisation of attachments in a Kennedy Class 2 situation. A successful removable partial denture includes a precise diagnosis with meticulous treatment planning. However, re-establishment of partially edentulous arch is particularly challenging in distal extension situations classified as Kennedy’s class 1 or 2 conditions.1 In such clinical cases, where a fixed prosthesis cannot be fabricated, a prosthodontist often suggests an implant retained prosthesis that is not routinely possible because of the insufficient available bone width and height.2 Thus to ensure functional and aesthetic substitution of lost teeth, an attachment secured RPD can be considered as a good treatment option in such cases. Attachments are constructed in a ready to place form (pre-fabricated) known as precision attachments. Another one is semi precision attachment where the segments have to be constructed by dentists or dental technicians because it requires casting for incorporating into fixed unit of restoration.3 Hence precision attachments are considered as possible alternatives when patients demand for a fixed restoration in distal extension cases. Various extra coronal attachments are available and used in distal extension cases. Preci-Sagix is considered as an ideal extra coronal attachment for removable partial dentures and also in over denture cases. It is accessible in two sizes, 1.7 mm mini or 2.2 mm standard and is selected according to the permitted space. The male component is available in three varieties, a plastic castable pattern (any hard alloy), cast to no prax (only non-precious alloy) and a threaded male and base ring (2.2 mm size only).4 These attachments produce vertical, horizontal and rotational movements during its function which supports the prosthesis by transferring harmful forces from the abutments to the supporting structures by its passive movement, which helps in the rehabilitation of distal extension cases.5 This case report explains restoration of partially edentulous arch by incorporating a Preci Sagix attachment in mandibular cast partial denture retained by a six-unit FPD and a maxillary conventional cast partial denture.

Abstrak: Bucket teeth adalah komponen attachment yang sering digunakan pada heavy equipment salah satunya yaitu bucket wheel excavator, yang fungsinya untuk material handling. Prinsip kerja bucket wheel excavator adalah continuous excavators, namun dalam pengoperasinnya bucket teeth sering terjadi kendala yang dapat mengganggu proses produksi. Salah satu kendala yang sering terjadi adalah keausan pada bucket teeth. Bucket teeth harus mempunyai ketangguhan dan kekuatan bahan yang tinggi, sehingga dapatmempengaruhi life time dari komponen tersebut dan mengurangi down time. Dalam penelitian ini akan dibahas mengenai karakterisasi material bucket teeth pada BWE (Bucket wheel excavator) dengan menggunakanmetoda pengamatan metalografi, pengujian komposisi kimia, dan pengujian kekerasan yang berguna untuk mengetahui harga kekerasan pada bucket teeth dengan, demikian dapat memberi informasi kepada industri lokal dan perusahaan yang menggunakan bucket teeth mengenai spesifikasi material yang cocok untuk pembuatan bucket teeth. Adapun hasil pengujian metalografi, analisa komposisi kimia bucket teeth adalah termasuk material baja paduan sedang yang mengandung silicon, mangan dan krom yang mempunyai sifat tangguh, tahan korosi dan tahan aus. Diliahat dari struktur mikro dan kekerasan mempunayai struktur martensit temper dan harga kekerasanya rata-rata 468 BHN. Dengan adanya porositas dan permukaan specimen yang kasar dapat diperkirakan bahwa proses pembuatan bucket teeth menggunakan proses pengecoran (casting), dan diikuti dengan pengerasan (hardening) dan temper

Successful root canal therapy requires an in-depth knowledge of root canal morphology.False assumptions about the root canal anatomy of teeth may lead to misdiagnosis, missed canals, improper debridement and breakage of root canal instruments during root canal treatment. The objective of this paper was to review the various methods used to study and understand root canal systems. The complexity of root canal morphology presents a challenge to any clinician. Any attempt to perform root canal therapy must be preceded with a thorough understanding of the anatomy of both the pulp chamber and the root canal system.Several methods have been used to examine the root canal system ranging from in vitro methods such as sectioning of teeth, metal castings to advanced in vivo tomographic imaging, along with the use of magnificationBangladesh Journal of Dental Research and Education Vol.5(2) 2015: 59-63

Using the clinical and radiological methods of investigation, the results of an assessment of the state of 287 metal-ceramic prosthetic structures were presented during the warranty period of their use in 186 people (53 men and 133 women) aged from 29 to 62 years who were made dental treatment and prophylactic institutions, located in the city (1 group of patients, 120 people) and rural areas (2 patients, 66 people) in the Krasnodar Territory of various forms of ownership. When assessing the condition of denture prosthesis, prosthetic bed and field, inflammatory changes in the periodontium, mobility and inflammation of the pulp of supporting teeth, recession of the gum, pressure ulcers in the region of the body of the bridge, contact between the prosthesis and antagonizing teeth in the central occlusion or overstrain of the occlusion in several units of dental prostheses structures, the presence of a large washing space in the area of the body of the bridge in the front sections of the dentition rows of the jaws, fracture castings, chips ics, chronic periapical foci of odontogenic infection of teeth under single, welded or supporting artificial crowns, as well as cementing of structures and the presence of hypersensitivity of teeth under artificial crowns. The frequency of occurrence of defects in dentures and complications of prosthetics, which were more often detected in persons who were prosthetically tested in health facilities, was determined, regardless of the form of their property located in rural areas. It is shown that at the moment many of the possible complaints and complaints of patients, in connection with the manufacture of metal-ceramic dentures, can prove to be justified. It is concluded that the introduction of internal quality control of medical care in all dental hospitals, clinics and offices, regardless of their territorial location and form of ownership, is a requirement of the time.

<p><strong>Background:</strong> Clinicians are continually challenged to improve the standard of treatment. Careful measurements and designs, based on knowledge of tooth loss patterns and biomechanical principles, will determine the overall quality of removable prostheses.</p><p><strong>Objectives:</strong> This study maps the pattern of tooth loss in a sample of patients and the most efficient designs employed for their cobalt-chrome removable prosthesis.</p><p><strong>Material and Methods:</strong> Data was collected from gypsum casts, metal castings, and prescriptions sent to dental technicians. The sample included both men (44) and women (109). Information was obtained on their Kennedy classification, number of missing teeth in the maxilla and the mandible, the type of major connector fitted, and when additional indirect retainers with clasps were incorporated into the frame. The significance of the association between pairs of these categorical variables was tested by a Chi Square test.</p><p><strong>Results:</strong> Patients with maxilla loss (82%) had mostly (54%) 6 to 10 missing teeth and were assessed principally (78%) as exhibiting Kennedy Class II or III patterns. Most (77%) of those missing teeth in their mandible (66%) were assessed as either Class I or Class II. The Anterior-Posterior (70%) in the maxilla and the Lingual Bar (74%) in the mandible were the most common fitted connectors. Indirect retainers were used for patients with maxilla (78%) or mandible (96%) tooth loss to provide extra stability.</p><p><strong>Conclusion:</strong> Additional components incorporated in the Cobalt-Chrome frame increased the biomechanical efficiency of the appliance by reducing destructive forces, caused by the torque on the abutment teeth.</p>

The surface modifications in teeth increase the retentive strength of cemented castings by providing micro as well as macro retentive ridge and groove patterns. Restoring the dental implants with cement-retained prosthesis is well known. Therefore, it is of interest to compare retentive property of implant abutments with and without circumferential grooves. Hence, 20 straight shoulder type titanium abutments were with abutment screws as well as prefabricated plastic copings and corresponding 12 mm-long stainless steel laboratory implant analogs were used. The abutments were divided into two subgroups of 10 abutments each: without grooves and with grooves. After thermocycling and storing the cemented abutments in water at 37°C water for 6 days they were assembled in the Universal testing machine and subjected to a pullout test (retention) at a crosshead speed of 5.0mm/min to record forces in Newton. Data suggest that the addition of grooves increased the retention. The mean retentive forces of standard machined abutments (plain) cemented with Resin modified GIC showed 339.34 N. Retention increased by 667.39N after addition of circumferential grooves. The surface modification of an implant abutment by means of circumferential grooves is an effective method of improving the retention of cast crowns cemented with resin modified GIC especially in short abutments.

The article presents the results of evaluating the prototyping of metal-ceramic structures made by casting and selective laser sintering. To achieve this goal, 27 patients with fabricated metal-ceramic crowns and bridgeworks were examined. Two study groups were created. The first group included 14 patients for whom dental prosthesis frameworks were made by casting. The second group consisted of 13 people, for whom the frames of dentures were made by the method of selective laser sintering. The analysis of clinical effectiveness was carried out according to the following criteria: 1- precision of the felling of prosthesis frame to solid tissues of abutment teeth; 2- the condition of the marginal periodontium; 3- the integrity of the ceramic cladding. The results of the study showed that the precision to solid tooth tissues of metal-ceramic dental prostheses made by laser selective sintering is higher than of frames made by casting. In accordance to the second criteria the best results were also shown by the participants of the second group. No chipping of the ceramic veneer from the metal-ceramic denture frameworks made by laser selective sintering was found. Thus, dentures which frameworks are made by the method of selective laser sintering are characterized by a higher objective assessment of their precision to the solid tissues of the abutment teeth. Lesions of the marginal periodontium both inflammatory and dystrophic were less in the participants of the second group. The frequency of defects in the coating of metal-ceramic dentures was significantly lower in the case of fabrication frameworks by laser selective sintering.

Periodontal disease causes destruction of adjuvant structures of the teeth predominate in all groups, ethnicities, races and both genders. Systemic antibiotic therapy is employed in treating this diseased condition, but it has limited due to the lack of accessibility to periodontopathic organisms in the periodontal pocket. These controlled intra-pocket devices also help in the maintenance of therapeutic drug concentration for the desired period of time. The goal of this research was to fabricate controlled release dental films, loaded with Tinidazole as an antimicrobial agent which consists of a common nonbiodegradable polymer and a co-polymer in different proportions for targeted delivery of drug. Nine formulations of Tinidazole dental films were prepared with ethyl cellulose as the main common non- biodegradable polymer and different co-polymers like PVPK30, HPMC K4M, Eudragit RL 100 in three ratios using solvent casting method. These films were evaluated for various parameters like thickness uniformity, content uniformity, swelling index, percentage moisture loss, in vitro drug release studies etc. Based on these parameters best film was selected as the one which is prepared with ethyl cellulose and eudragit RL100 (20%w/w of ethyl cellulose) i.e F5, since it can release the drug above MIC in each day of treatment and it is having sufficient drug content and other required film characteristics. The kinetic models of the formulation F5 was then found and it indicated that the formulation undergoes zero order release kinetics and model fits to Higuchi which is indicative of the diffusion mechanism of drug release. The mechanism of drug release was found to be Non-Fickian. From all of these studies it was concluded that Ethyl cellulose - Eudragit RL100 (20%w/w of EC) combination is the best carrier among the other polymers for the Tinidazole film for the treatment of periodontitis.

Devido a evolução dos sistemas cerâmicos, atualmente, são permitidas inúmeras associações de materiais restauradores. Entretanto, mimetizar as características visuais das próteses livres de metal com próteses metalocerâmica permanece um desafio. Assim, o objetivo deste trabalho foi relatar o caso clínico de substituição de próteses desadaptadas, homogeneizando próteses parciais fixas livres de metal e metalocerâmicas dento e implantossuportadas, após cirurgia periodontal. O paciente de 55 anos, gênero masculino, compareceu à Clínica de Prótese Parcial Fixa, da Faculdade de Odontologia de Araçatuba – FOA/UNESP em 2017 queixando-se dos seus dentes anteriores estarem “feios” e com a “raiz aparecendo”. No exame clínico foi constatada recessão gengival nos elementos 11 e 13, os quais continham uma prótese parcial fixa de três elementos metalocerâmicas desadaptada, prótese sobre implante nos elementos 21 e 22, que apresentavam-se desadaptadas e com estética desfavorável. No exame radiográfico pôde-se observar a presença de um núcleo metálico fundido nos elementos 11 e 13. Foi proposto, então, a confecção de coroas totais livres de metal nos elementos anteriores superiores (13, 12, 11, 21 e 23) e coroa metalocerâmica para o elemento 22. Para isso, foi realizado enceramento diagnóstico inicial e, após o consentimento do paciente, foi efetuada a remoção das próteses antigas. Com a remoção, visualizamos uma depressão na vestibular do rebordo na área do 12 (ausente), solucionado com um enxerto gengival subepitelial. Após a realização dos preparos dentários e moldagem com silicone de adição as peças foram confeccionadas com sistema e.max Ceram (Ivoclar Vivadent). Após a prova estética e ajustes oclusais iniciais, as peças foram preparadas para cimentação resinosa com o sistema Variolink® N (Ivoclar Vivadent). O cimento transparente foi selecionado previamente por meio de provas com o kit Try-In. 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