CAUSES OF MICRO-LEAKAGE Material An article written by Bagis et al. compared micro-leakage between silorane-based resin composite and nanohybrid-based resin composite restorations. The results of the study concluded that the enamel and dentin margins for silorane-based resin composite restorations showed no leakage. The nano-hybrid-based resin composite restorations presented with varying levels of leakage. Applying the findings of this study, a clinician may want to consider use of a silorane-based resin composite to limit micro-leakage experienced by the patient. Placement Instrumentation A study appearing in Operative Dentistry compared micro-leakage associated with a variety of instrument combinations used for composite placement. Four instrument combinations were assessed; a metal matrix with wooden wedge, a transparent matrix with reflective wedge, a metal matrix with wooden wedge and light tip, and a metal matrix with wooden wedge and bio-glass cylinder. The study found that exclusive use of a metal matrix with a wooden wedge, as compared to a transparent matrix and a reflective wedge, significantly increases marginal leakage. Using a conical tip, or other similar light-conducting instruments, significantly reduces micro-leakage to a level equivalent to that of a transparent matrix and reflective wedge. Applying the findings of this study, a clinician should no longer continue to solely use a metal matrix and wooden wedge. Intermediary Flow layer A study published in the Journal of Dentistry assessed cervical enamel micro-leakage with and without an intermediary flowable resin-based composite (RBC) layer for the incremental restoration of mesio-occluso-distal (MOD) cavities. Use of an intermediary flowable resin-based compo... ... middle of paper ... ...ent. 2007;35(6):482-9. 5. Schneider H, Busch I, Busch M, Jentsch H, Häfer M. Effect of operator-specific handling on tooth-composite interface and microleakage formation. Oper Dent. 2009;34(2):200-10. 6. Venturini D, Cenci MS, Demarco FF, Camacho GB, Powers JM. Effect of polishing techniques and time on surface roughness, hardness and microleakage of resin composite restorations. Oper Dent. 2006;31(1):11-7. 7. Pongprueksa P, Kuphasuk W, Senawongse P. Effect of elastic cavity wall and occlusal loading on microleakage and dentin bond strength. Oper Dent. 2007;32(5):466-75. 8. Fugaro OJ. COMMENTARY. Effect of prerestorative home-bleaching on microleakage of self-etch adhesives. J Esthet Restor Dent. 2010;22(3):193. 9. Khoroushi M, Fardashtaki SR. Effect of light-activated bleaching on the microleakage of Class V tooth-colored restorations. Oper Dent. 2009;34(5):565-70.
Khosravi K, Ataei E, Mousavi M, et al. Effect of Phosphoric Acid Etching of Enamel Margins on the Microleakage of a Simplified All-in One and Self-etch Adhesive System. Operative Dentistry 2009; 34(5):531-36.
...at more tentatively, with fluoride gels and varnishes or a chlorhexidine varnish. Some dentists may restore root caries with amalgam restorations. Another treatment option used by some dentists to restore root caries is Glass Ionomer Cements. Glass ionomer cements were first introduced in the early 1970s. They have good adherence to mineralized tooth tissue, which keeps the removal of tooth structure to a minimum. Glass ionomer cements also have the ability to leak and absorb fluoride into the tooth, which decreases the rate of secondary caries. These factors have increased the potential for glass ionomer cements to replace amalgam as a restorative material. (Hammel)
Teeth #1, 16, and 17 are unerupted. There is a PFM on tooth #22. There were two 3-unit bridges: teeth #19 through 21 with a gold abutment on tooth #19, the pontic on tooth #20 and a PFM abutment on tooth #21, as well as on teeth #23 through 25, with PFM abutments on teeth #23 and 25, and the pontic on tooth #24. The amalgam restorations are as follows: an MO on tooth #2 and an MOD on teeth #3 and 5. There are cervical composites on teeth #3 and 4. Tooth #15 was missing the crown. Tooth #13 was a root tip. There are class two furcations on the lingual surface of teeth #1, 18, and 19, and a class one furcation on the buccal surface of tooth #18. There is 2mm of recession on the facial surfaces of teeth #4, 5, 6, 7, 8, 15, 29, 25, 26, and 27, as well as the lingual surfaces of teeth #3, 5, 6, 7, 8, 15, 21, 22, 26, 27. There is 4mm of recession on the facial surfaces of teeth #3 and 23, as well as the lingual surfaces of teeth #12, 23, and 25. There is 6mm of recession on the facial surface of tooth #22. Teeth #3, 4, 18, 26, and 27 had attrition. There was erosion on the lingual and incisal surfaces of teeth #8 through
Tooth surfaces are referred to by various names in dentistry, including mesial, distal, buccal, and lingual. If you drew a midline t...
Adhesion of resin materials to tooth structure has been a challenge in the history of adhesive dentistry. Currently, bond durability is one of the main research topics in adhesive dentistry. Regardless of the improvements in bonding technology, resin dentin bonds show limited durability for both etch and rinse and self-etch adhesive systems.
... teeth was 79% and 65% in the permanent first molars. The arrest rate for caries on both permanent and primary teeth was 77%. In comparison, a study done on children in Greenland, the arrest rate for dentinal caries applied with just NaF varnish was only 33%(Ekstrand, et al; 2010)
Dental composites, also known as "white fillings", are a group of restorative materials composed of a mixture of powdered glass and plastic resin regularly used in modern dentistry to resemble the appearance of the natural tooth. Acrylic resin was first introduced to the dental profession in the mid 1950s. Since their introduction, acrylic based materials have continued to play a pivotal role in restorative and prosthetic dentistry. After the introduction of the bisphenol A glycidyl methacrylate, or BIS-GMA, by Bowen in the early 1960s the potential application of resins has emerged. This composition and formulation possessed a higher molecular weight and therefore better mechanical properties and reduced polymerization shrinkage, the newer polymer offered potential for much greater applications that included anterior and posterior composite resin restorations, indirect inlays/onlays, pit and fissure sealants and more wear resistant denture teeth.
The future of dentistry is the end of the use of amalgam restorations. Amalgam restorations are believed to be the cause of many illnesses for dental professionals. Dental professionals are exposed daily to the harmful chemicals contained in the material that makes up amalgam, including mercury. With the advent of resin restorations and their more popular use, amalgam restorations will be a thing of the past, only read about in dental history books.
Many clinicians and researchers have been concerned about the condition of tooth enamel erosion for many years, which led them to discover that dental erosion has been increasing steadily throughout the world. From the time of the children’s health survey in 1993 compared to 1997, erosion was shown to have increased (Lussi & Jaeggi, 2008). More tests and research based studies resulted in the information that erosion seems to be greater in older adults from 52-56 years old than it is in younger generations of people who range from 32-36 years old (Luggi & Jaeggi, 2008). It has become an issue that many people are suffering from dental erosion without being aware of it. It is very difficult to detect in most cases because the ones that have erosion are uneducated about the issue that they are facing with their teeth (Luggi & Jaeggi, 2008).
Throughout the history of dental medicine dentist have searched for the perfect material to aid in the treatment of the most common problem in people’s mouths, cavities. The material would also be useful in fixing chipped and broken teeth. Dentist needed a material that was strong, relatively low costing, easy to apply, durable, and able to limit the growth of bacteria. In the early 19th century in France dentist found their wonder material and that material was amalgam. The dental amalgam is constructed of a mixture of mercury and at least one other metal such as zinc, copper, tin, or silver. The combinations of these metals are the foundation of what gives silver amalgams their strong make up and shiny metallic appearance.
10. Gharizadeh N, Moradi K, Haghighizadeh MH. A study of microleakage in Class II composite restorations using four different curing techniques. Oper Dent. 2007; 32(4): 336-40.
It is an excellent tooth filling material which is used to restore decayed teeth. It has been one of the most popular and efficient filling material of choice by the dentists for more than one hundred years around the globe because of its strength, high longevity, ease of use and inexpensive material. (1,2)
...an be seen that composite teeth form a high stability bond than PMMA teeth. This is due to the filler content allowing for low shrinkage, increased wear resistance and better cross-linkage with the base. In overall consensus the technique of heat-curing is believed to achieve significantly more polymer cross-linkage than that of self-curing the acrylic resin PMMA base - giving us a stronger base to teeth interface. It should be noted however that both techniques can be used for denture fabrication to achieve a desired result and it is up to the dentist and the technician to determine which one they prefer however, composite teeth bonded to a heat-cured PMMA base works best. Though the tooth and base by themselves may be strong, if the interface between them is not strong, this will result in the overall denture produced being weak independent of material selection.
As opposed to the endodontic triad approach (consisting of biomechanical preparation, microbial control and complete obturation) , shaping to facilitate cleaning and filling might be a more appropriate concept considering that a major goal of root canal treatment is removal of microorganisms from the complex root canal system. Of course, while these objectives are being achieved, conservation of tooth structure and canal m...
Strength is an important property for restorative materials, which depends on the microstructure and composition of material, the method of testing the fracture mechanism and the environment (20). The measurement of compressive and flexural strength is one of the methods to investigate the mechanical properties of restorations (21). Flexural strength is one of important characteristics of MTA. This property becomes more important when the MTA is placed under occlusive pressures, such as when MTA is used as pulpotomy material or direct pulp coating or forcal perforation repair. In such cases, the flexural strength of the MTA should be greater than the strength of the amalgam condensation to prevent the fracture of the MTA. Considering the clinical applications of MTA and other suitable materials in perforation repair, the bonding strength of these materials is an important factor in providing a suitable and optimum seal between the root canal system and the material.