MARGINAL ACCURACY OF LUMINEERS VERSUS TRADITIONAL laminate VENEERS

Transcription

1 MARGINAL ACCURACY OF LUMINEERS VERSUS TRADITIONAL laminate VENEERS Thesis Submitted to the Faculty of Oral and Dental Medicine, Cairo University In Partial Fulfillment of the Requirement for the Master Degree in Fixed Prosthodontics By Meral Salah Saleh Nadra B.D.S Ain Shams University 2008 Fixed Prosthodontic Department Faculty of Oral and Dental Medicine Cairo University 2012

2 Supervisors DR. Hesham katamish Professor of fixed prosthodontics Dean faculty of oral and dental medicine Cairo university DR. Mona Attia El Agroudi Assistant professor fixed prosthodontics Facuty of oral and dental medicine Cairo University

3 Contents Contents Page No. Introduction 1 Review of literature 3 Aim of the study 29 Materials and Methods 30 Results 73 Discussion 92 Summary and Conclusion 104 Recommendations 107 References 108 Arabic summary أ

4 List of tables Table no. Title Page no. 1 The ceramic material used in the study 30 2 Composition of ceramic materials used in the study 31 3 Samples grouping 38 4 Manufacturer s firing data of the ceramic materials used in the study 56 5 Horizontal marginal gap results (Mean±SD) for all groups before/after cementation as function of measurement site {measured in µm microns} 74 6 Comparison of horizontal marginal gap results between Low fusing porcelain and CERINATE porcelain 75 7 Comparison of horizontal marginal gap results between prepared and non-prepared groups in µm 76 8 Comparison of horizontal marginal gap results between measurement sites (in µm) Comparison between horizontal marginal gap results before vs. after cementation (measured in µm) Comparison of horizontal marginal gap results between groups before cementation (in µm) Comparison of horizontal marginal gap results between groups after cementation (in µm)

5 List of figures Figure no. Title Page no. 1 LUMINEERS placement system kit by CERINATE 32 2 light body lumineers impression material 32 3 Etch N Seal 33 4 Tenure A and Tenure B adhesive 33 5 Tenure S 34 6 CERINATE prime and conditioner 34 7 Ultra-bond plus resin cement A Parallelometer 36 9 the tooth in the set epoxy resin block three-wheel depth cutter stone tapered stone with round end Window preparation design for laminate veneers prepared tooth after finishing and roundation of all sharp angles prepared tooth after finishing and roundation of all sharp angles Precision measuring, electronic digital caliper, china checking the thickness of the finish line after preparation of group1 and closer view at the digital caliper tip measuring the finish line thickness after preparation Figure (17), (18), (19): fast set polyvinylsiloxane impression material had been placed in the tray and around the finish line to avoid any air bubble inclusions impression before pouring die after setting of the dental stone wax pattern construction spruing 48

6 Figure no. Title Page no. 24 two sprued wax patterns oriented onto the ring base wax patterns inside the silicone ring the IPS silicone ring used for investing burnout heating furnace The EP 600 Pressing Furnace the investement ring placed at the centre of EP 600 press furnace the investment ring left to cool on the IPS Empress cooling rack the investment ring separated at the predetermined mark using a separating disc 32 polishing jet Etchant for the Ips Empress Esthetic application of the etchant to the Empress veneers application of porcelain conditioner application of CERINATE prime Etching of the enamel surface application of tenure A&B to the prepared surfaces applying tenure s to the prepared surface showing sample in place under the predetermined load of the cementing device 41 application of the resin cement Figure (42,43): removal of the excess cement with a brush dipped 43 in tenure S. 44 showing Sapphire-Plus light curing unit LUMINEERS Finishing Kit (No ) Showing Bur G cleaning any leftover resin cement showing Bur C smoothing out any porcelain ledges showing the mosquito diamond bur F refining the interproximal margins 49 showing bur D for final polishong of the LUMINEERS

7 Figure no. Title Page no. 50 showing the polishing cup and paste for polishing showing the SEM and accompanying analysis screens Screens attached to the SEM showing the teeth blocks inside the SEM chamber Showing teeth blocks fitted on the special mounting device Histogram of horizontal marginal gap mean values for all groups before/after cementation as function of measurement site Histogram comparing horizontal marginal gap mean values between Low fusing porcelain and CERINATE porcelain Histogram comparing horizontal marginal gap mean values between prepared and non-prepared groups Histogram comparing horizontal marginal gap mean values between measurement sites Histogram comparing horizontal marginal gap mean values before vs. after cementation Histogram comparing horizontal marginal gap mean values between groups before cementation Histogram comparing horizontal marginal gap mean values between groups after cementation Scanning electron micrograph (x80) showing a gap width at the cervical margin that is tapering at the sides with maximum width 81 more or less at the mid-cervical margin but it s not very wide. 62 Scanning electron micrograph (x250) showing comparatively very narrow gap proximally; noticing that there are unfilled parts along the interface may be due to the very narrow gaps making it 82 harder for the try-in paste to fill it. 63 Scanning electron micrograph (x250) showing proximal gap width readings that are emphasizing the previous micrograph 82 readings of the opposite side.

8 Figure no. Title Page no. 64 Scanning electron micrograph (x80) showing the cervical margin 83 with a homogenous gap width along the cervical margin. 65 Scanning electron micrograph (x250) showing a narrower gap 83 width proximally than in the cervical margin reaching half or less the gap width readings than the cervical margin, noticing that in some parts the try-in paste along the interface is not completely filling the interface leaving unfilled spaces at the interface. 66 Scanning electron micrograph (x250) showing scanning electron 84 micrograph showing a narrower gap width proximally than in the cervical margin relatively same readings as the other proximal side. 67 Scanning electron micrograph (x80) showing a very wide, 84 homogenous gap tapering at the sides with the maximum width of the gap at the middle cervical margin. 68 Scanning electron micrograph (x250) showing a very wide gap 85 noticing an irregular interface between the try-in paste and the ceramic veneer margin; leaving some unfilled parts at the interface due to dragging out of the try-in paste during removal of the excess. 69 Scanning electron micrograph (x250) showing a very wide gap 85 noticing the interface at this side between the try-in paste and the ceramic veneer margin was more or less smooth. Consistent readings with no significant variation in the gap width between the two proximal sides; noticing small gaps at the interface between the ceramic veneer and the try-in paste due to dragging out of the material. 70 Scanning electron micrograph (x80) showing relatively narrow gap width tapering at the sides with the maximum width at the mid-cervical region. with little insignificant unfilled grooving along the interface. 86

9 Figure no. Title Page no. 71 Scanning electron micrograph (x250) showing narrow gap width 86 that is totally filled with no grooves along the interface. 72 Scanning electron micrograph (x250) showing narrow gap width with no significant difference between both sides. The readings are relatively having the same gap width as the other proximal surface of the tooth Figure (73) indicating the homogeneity of the pressure the ceramic veneer was subjected to during cementation Scanning electron micrograph (x80) showing narrow 87 homogenous gap width 74 Scanning electron micrograph (x250) showing completely filled 88 interface with some disturbance in the cement layer resulting from the finishing procedures. 75 Scanning electron micrograph (x250) showing homogenous 88 relatively narrow gap width along the interface. 76 Scanning electron micrograph (x80) showing relatively narrow gap 89 width that is more or less homogenous. 77 Scanning electron micrograph (x250) showing irregular interface gap 89 widths, noticing that the ceramic veneer is not well adapted on the tooth surface leaving furrows along the whole interface. 78 Scanning electron micrograph (x250) showing irregular interface 90 gap widths along the proximal margin as the previous micrograph; noticing there is no significant difference in the readings along the interface on the two sides. In addition to the presence of the furrows along the interface indicating no good adaptation between the ceramic veneer and the tooth structure 79 Scanning electron micrograph (x250) showing homogenous gap width 90 but with bulging excess cement at some parts indicating that some parts have been abraded along the interface. 80 Scanning electron micrograph (x250) showing a more or less homogenous gap width with readings relatively similar to the other side indicating the equal pressure during cementation. 91

10 List of Diagram Diagram Page No. Diagram (1 ): diagram showing the window design of laminate veneers Diagram (2): a diagram showing the cementing device components 42 62

11 Review of literature Review of literature The demand for tooth-colored restorations has grown considerably during the last decade (1). This overwhelming trend has been both a bane and a boon to the dental profession. As the world nowadays strives towards perfection and excellence, Esthetics and beauty have also gained importance and professionalism in dentistry (2). Cosmetic dentistry nowadays have become a necessity for everyone in the dental profession; noticing that Changing trends, concepts and treatments for dental disease have made it necessary to diversify dental services. (2) Recent modifications and advances in the techniques of bonding porcelain to enamel created the possibility of the porcelain veneers to become an alternative to the use of full crowns in treatment of many clinical situations such as diastemas, worn dentition, chipped teeth, malaligned and excessively discolored teeth. Veneers were considered to be a more conservative approach because its preparation was thought to involve less tooth reduction than full crown preparations. Although this is technically true it was actually found that the traditional porcelain veneer preparation procedures needs aggressive tooth reduction similar to the three-quarter crown preparations (3). This conventional approach requires local anesthesia, considerable treatment time and temporaries are needed to be fabricated in most cases, so after all it was concluded that the traditional porcelain veneer preparation were still aggressive. This 3

12 Review of literature urged dental companies to find a less aggressive approaches that copes more with the minimally invasive dentistry. (3) This led finally to a truly conservative approach in the world of porcelain laminate veneers referred to as the no-prep technique, this technique is characterized by minor adjustments of enamel in selected locations or in many cases no preparation of teeth at all preserving the natural tooth structure. (3) The no prep technique was made possible by advances in custom-designed bonding systems and in porcelain materials which are of high strength allowing it to be fabricated into exceptionally thin veneers in the range of mm. knowing that this thickness range there is no need to cut down bulk of tooth structure to accommodate the thickness of the porcelain veneers. (3) CERINATE LUMINEERS that are considered one of the best following the no prep technique introduces an alternative to traditional veneers that can be easily marketed and implemented to a versatile age group. The advantages of this system are that the LUMINEERS can be made as thin as a contact lens and may be placed over existing teeth without having to remove healthy tooth structure. In cases where tooth reduction is necessary, it can be kept conservative. These properties attract many seniors who may be concerned about complications with their medications to local anesthetic or about general health during a routine dental procedure. (4) 4

13 Review of literature Introduction of laminates as an effective esthetic alternative has overtaken all the conventional options and specially its conservative approach in its preparation will always make a sensible dentist to think before going on to any alternative esthetic procedure. (2) History of laminate veneers : Charles Pincus a California dentist in 1938 first invented teeth ceramic veneers that were thin-facings of air-fired porcelain attached to sound teeth with adhesive denture powder to mask the unesthetic teeth of actors and actresses but it was debonding shortly after placement as denture adhesives bonded it. (5) Later In 1982 Simonsen and Calamia (6) had modified the technique as they discovered that porcelain can be etched using hydrofluoric acid and bond strengths could be achieved between composite resins and porcelain that were predicted to be able to hold porcelain veneers on to the surface of a tooth permanently and that was confirmed by Calamia (7) in an article describing a technique for fabrication, and placement of Etched Bonded Porcelain Veneers using a refractory model technique In 1983, whereas Horn (8) described a platinum foil technique for veneer fabrication. Kihn and Barnes,1998 evaluated the clinical longevity of a brand of porcelain veneers and its accompanying cementation system in a study using fifty-nine porcelain veneers that were pepared and placed in 12 patients by one practitioner and was evaluated using modified ryge criteria at baseline and 12 months. They found that Over the past 20 years veneers were 5

14 Review of literature constructed using various techniques and materials such as direct composite resin, preformed acrylic laminates and laboratory fabricated acrylic resins, microfill composite resins, porcelains and glass ceramic veneers. (9) Preformed acrylic laminates and composite veneers were found to discolor and develop surface stains overtime (9). Composite resin veneers undergo surface abrasion and softening caused by solvents present in some mouth rinses, toothpastes and alcoholic beverages. (10,11,12) The introduction of the porcelain veneer brought about many advantages and solutions not only for the dentists and dental technicians but also for patients as well; because of its peculiar properties as it s strong, durable, esthetically pleasing maintaining their color stability and do not harm the peridontium (9). Along with the innovations in the types of porcelain used in fabrication of the veneers; Bonding agents and adhesive systems are being developed as well in order to reach the ultimate bond between the tooth structure and porcelain leading to more durable restorations, superior bond strength, marginal adaptability and therefore better esthetics. (13) The majority of teeth receiving porcelain laminate veneers should have some enamel removal, usually about 0.5mm that allows for the minimal thickness of porcelain (14). Christensen 1991 (15) states that the optimal amount of enamel that should be removed is 0.75mm however, according to patroni et al 1992 (16) the extent and thickness of the enamel gingivally in anterior teeth 6

15 Review of literature doesn t permit a reduction of 0.5mm without exposing dentine, which may be a cause of postoperative sensitivity. While Natress et al (17) in an in vitro study examining the depth of preparation and the incidence of dentin exposure resulting from a freehand technique to prepare maxillary central incisors for porcelain veneers. It was found that in case of freehand preparation the proximal and cervical enamel was reduced more than 0.5mm and exposure of dentin was inevitable in majority of cases. Paul et al (18) proposed the application of the dentinbonding agent immediately after completion of tooth preparation; as this technique may prevent bacterial leakage and dentin sensitivity and was associated with improved bond strength in vitro. Regarding the incisal preparation for porcelain veneer there are three basic techniques used the window technique, the overlapped incisal edge and the feathered incisal preparation (14,15) There was a debate on which type would result in less stresses and occlusal load on the veneer but as a conclusion it was found that if strength is the primary concern the most conservative preparation design would be using the window design. (19) Dhawan et al (20) conducted a study to assess to both clinical and scanning electron microscopy of porcelain and ceromer resin veneers,the study was proposed as ceromer resin was expected to provide a cost effective modality alternative to porcelain veneers. the study was done to evaluate the surface finish and esthetic quality clinically and by scanning electron microscope as well at 12 months period. Seventy-two veneers, 36 7

16 Review of literature porcelain and 36 ceromer resin veneers were placed in 12 patients and were luted with opal luting composite and scotchbond multi purpose system and the SEM assessment was made by quantitative analysis of the marginal fit of the two veneering materials.it was found that although ceromer exhibited a good anatomiacal form during the study period there were changes in color, surface appearance, marginal adaptation, increased marginal discoloration, and tissue response. Inability to achieve a good finish with high gloss was a major drawback of the ceromer. Porcelain exhibited better esthetics, marginal adaptation, finish qualities, and tissue response. The SEM showed good to excellent marginal fit at baselinne in ceromer and porcelain veneers, but loss of luting resin at the margins was evident in both the materials after 12 months, leading to visible gaps in a number of veneer restorations. Ceromer veneers exhibited poor surface characteristics in several restorations, which further degraded in oral conditions over 12 months. DiTolla 2005 (21) carried out a study Prep & No-prep Comprehensive Porcelain Veneers Techniques concluded that Although material should not determine the amount of preparation of tooth structure that will be removed, Traditional porcelain veneers materials that have been used in the past 30 years needs a specific amount of tooth preparation according to the type of porcelain used to give the sufficient bulk to the porcelain to maintain its strength. This brought about some drawbacks like cutting through dentin causing postoperative sensitivity in most cases. 8

17 Review of literature During the past 25 years, there has been an ongoing debate regarding the preparation techniques used for porcelain veneers. Calamia 1983 (7) and other early pioneers looked at veneers as a noninvasive, additive process and worked primarily with a nopreparation concept but it didn t meet the success because of the type of porcelain used back then wasn t strong enough. As porcelain laminate veneers became one of the most common if not the first choice when considering esthetic bonded restorations because of its natural translucency and its ability to be manipulated in laboratories creating a beautiful transition of colors that mimics the polychromatic nature of natural tooth structure and because of the fact that glazed porcelain was found to be the most biocompatible dental material in the oral cavity; these made the porcelain the best candidate for constructing a natural looking durable, functioning and strong laminate veneers that last for long years. (22) Tooth preparation for porcelain veneers has undergone a cyclical evolution. It began in the early 1980s with minimal or no preparation, progressed to more aggressive tooth reduction in the 1990s, and today, has returned to very little, if any, tooth reduction when possible. (23) Ceramics overview: In an article reviewed by Font et al. (24) about the choice of ceramic for use in treatments with porcelain laminate veneers. Ceramics can be classified according to their composition into two main groups, silicate ceramics and oxide ceramics. Silicate ceramics are further classified into feldspates and alumina 9

18 Review of literature porcelains. feldspates in which silica oxide is the predominant component 46-66% versus 11-17% alumina are sub-classified into conventional feldspate porcelain and the high resistance reinforced feldspate porcelains. The low fracture resistance of the conventional feldspate porcelains which reaches 56.5 Mpa urged the evolution of the higher resistance reinforced feldspathic porcelain that lead to diversification of the present dental porcelain materials used.either the leucite reinforced feldspathic porcelain or the lithium di silicate reinforced feldspathic. Porcelain which reaches mpa respectively are the most widely used porcelain nowadays specially for porcelain laminate veneers. As a result of the pressing process used to manufacture the leucite reinforced feldspathic porcelain, the porosity is reduced and adequate and reproducible fit precision is achieved. The perfect distribution of the leucite crystals within the glass matrix observable during the cooling phase and after pressing, contributes to increase resistance without significantly diminishing translucency. (24) Glass ceramics consists of glass matrix phase and at least one crystal phase that is produced by controlled crystallization of glasss. It s available in castable, machinable, pressable and infiltrated forms which is used in all types of ceramic restoration. (25,26) The pressable glass ceramic is the type that involves pressure moulding in the manufacture process. Heat pressed ceramics were introduced in dentistry in the early 1990 s; in which 10

19 Review of literature the restoration is waxed, invested and pressed in a manner somewhat similar to that of gold casting. Ceramic ingots are pressed at high temperature over a 45 min. period into a refractory mold made by the lost-wax technique. Two finishing techniques can be used; characterization technique and the layering technique which lead to a translucent ceramic core with advantages of moderately high flexural strength, excellent fit and esthetics. The first generation of the heat-pressed ceramics was leucite-based e.g. IPS EMPRESS 1 (SiO 2 -AL 2 O 3 -K 2 O), while later generations involves the use of lithium disilicate e.g. IPS EMPRESS 2 (SiO 2 - Li 2 O) (25,27). IPS EMPRESS was released in the market in the early 1990 s this material was used to fabricate veneers, inlays, onlays and crowns, the chemical composition was based on the SiO 2 -AL 2 O 3 - K 2 O system and the microstructure consisted of homogenously dispersed leucite crystals (KALSi 2O 6 ) embedded in a glassy matrix (28) IPS EMPRESS ESTHETIC was recently introduced after that as an improved product that offers a more homogenous microstructure where the leucite crystals are more evelnly distributed with increased density and smaller grain size with subsequently enhanced esthetics, it consists of highly esthetic reinforced glass-ceramic with a chemical composition of more than 98% SiO 2 BaO,AL 2 O 3, CAO,CeO 2,Na 2 O,K 2 O,B 2 O 3,less than 2% TiO 2 and pigments;it has been clinically tried and tested for years being characterized by excellent strength values and outstanding esthetic appearance and thus it s used in fabrication of all ceramic restorations such as inays,veneers and crowns. (29) 11

20 Review of literature MCLAREN 2009 (30) did a research reviewing different classes of ceramic materials in which it was found that ceramics and dental porcelain with its different classes in dentistry have been invading the field of esthetic dentistry in the past 25 years with an overwhelming modifications in the microstructural components and processing techniques in order to enhance the properties for the good of the patients. It was concluded that Properties of ceramics may differ greatly according to the microstructure of each type of porcelain, it can be very translucent to very opaque affected by many factors such as the ratio of the non-crystalline glassy microstructure to the crystalline structure which if it s high gives a more opaque type of porcelain, additionally Porcelain particle size, particle density, refractive index and porosity are also contributing factors in different properties of different ceramic materials. According to the Microstructural components of porcelain, ceramics can be classified into four major categories, category 1,which is a glass based system containing mainly silicon dioxide with various amounts of alumino-silicate glasses called feldspars, category 2 which is the glass based systems with fillers that differ according to the type of crystals that have been added or grown within the glassy matrix, category 3 is the crystalline based systems with glass fillers and the fourth category is the polycrystalline solids. (30) Pressable ceramics were manufactured to be extremely dense and demonstrating much higher strength ratings such as flexural strengths up to 180 MPa and due to this improved strength 12