Ceramir Crown & A ; Bridge ( Ceramir C & A ; B ) is the chief merchandise of DOXA AB. It is the first of all time invented merchandise based on the Ceramir engineering which belongs to the stuff group Nanostructurally Integrating Bioceramics i.e. , NIB ( H. Engqvista et al. , 2001 ) .
Ceramir hardens by fade outing with H2O foremost which wets the tooth, and continues to recrystallize as nanocrystalline hydrates which precipitates on the wall of the tooth, making a basic pH ( L. Hermansson et al. , 2003 ) . This mechanism is based on surface energy and mechanical engagement at Nano-level, and this whole procedure is called nanostructural integrating. Ceramir chemically resembles hydroxylapatite, which is a major constituent of dentition and this helps ceramir to fit natural dentitions in its composing. It has the capableness to make a natural zone of contact without any mechanical or thermic emphasis for which its unique belongingss are really of import ( L. Hermansson et al. , 2006 ) .
Properties and waterproofing:
To understand sealing mechanism it ‘s of import to discourse mechanical belongingss, thermic belongingss, and physical belongingss of ceramir ;
1. It has a basic pH which is helpful to keep a neutralized stable environment even when sourness increases inside the oral cavity ( L. Hermansson et al. , 2003 ) , and it is an of import demand for the stuff to stay bioactive, by agencies of which it produces hydroxyapatite on the surface whenever it comes in contact with phosphate solutions ( Pameijer CH, 2009 ) . Hydroxyapatite has some particular belongingss as follows ;
a. Hydroxyapatite decomposes at temperature between 800-1200A°C, and is an unstable compound thermally.
B. Large volume of hydroxyapatite fails to retain long term burden bearing, and does n’t hold mechanical strength.
2. It takes over the belongingss of hydroxyapatite when it comes into contact with phosphates and crystallizes of course into a Nano crystalline construction ( L. Hermansson et al. , 2003 ) .
3. It interacts with the tooth tissue through the mechanism of Nano structural integrating, and remains bioactive in the unwritten environment ( L. Hermansson et al. , 2003 ) .
4. Physical belongingss like hardness, flexural strength, solubility are outstanding, and are really of import for biocompatibility ( Pameijer CH, 2009 ) .
5. In vivo surveies on Primatess supported by X raies from homo on clinical test has revealed that Ceramir C & A ; B is a stuff with highly non-irritating and bland features in the unwritten environment which makes it more widely used stuff ( Pameijer, C.H et al. , 1988 ) . It stands out when compared to other stuffs. There are histological ratings and clinical test studies which prove its non-irritant belongingss ( Pameijer, C.H et al. , 1988 ) .
6. The stuff does non shrivel at all, has opposition to impact, scratch and has a life-time functioning quality ( R J Mangabhai et al. , 2001 ) .
7. Since it is calcium aluminates based system, the turnover of H2O is really high during the hardening procedure ; this shows it binds tonss of H2O inside the stuff throughout the procedure of indurating. This sum of H2O is straight relative to the strength of the stuff, and is several times greater than that of other Ca phosphate systems. It besides causes a big fluctuation in its viscousness and composing ( R J Mangabhai et al. , 2001 ) .
8. It has a really rapid hardening capacity which is a most of import demand in dental stuffs. The hydrates formed by nano crystallisation contain ions which are formed from the dissolved chemical pulverization ( stuff ) and H2O. When the concentration of the ions reaches a certain degree, the stuff forms a lasting construction. The freshly formed stuff has two hydrates ; Katoite and Gibbsite ( H. Engqvista et al. , 2001 ) .
9. Katoite is chemically calcium aluminum oxide hydrate and built of crystals each with size 10-40 nanometers. Gibbsite is chemically aluminium hydrated oxide and signifiers crystalline gibbsite over clip. And this stuff attaches to the tooth by the Nanostructural integrating as explained before ( H. Engqvista et al. , 2001 ) .
10. Ceramir has natural thermic features of dentitions like, thermic conduction and elastic modulus. It has thermic belongingss similar to enamel and dentine, which helps to understate the consequence of thermal daze when it faces sudden temperature alteration. And it is able to travel along with the tooth, avoiding the formation of spread ( Pameijer CH, 2009 ) . The thermic belongingss of ceramir and other dental stuffs are tabulated below:
( in GPa )
( in W/mk )
( in ppm/k )
11. For a good contact between the stuff and the dental tissue viscousness and rheology are besides of import. There are many different mechanisms by which stuffs attach to weave like, creative activity of mechanical lock between stuff and tooth abnormalities, by usage of adhesives, and by chemical bonding ( Pameijer CH, 2009 ) .
The different clinical probes resulted in saying that the pulverization and liquid constituent commixture was easy. It was a smooth process to follow, its working and setting clip were about 2 – 2.5 and 4 – 5 proceedingss and comparatively were superior to other cements by and large used in clinics ( S R Jefferies et al. , 2009 ) .
Clinical surveies were carried out for a twelvemonth with the dental cement Ceramir C & A ; B, on 38 Crowns and 17 patients with span abutment. Their scene frosts, working times and managing features were recorded during this period ( S R Jefferies et al. , 2009 ) . Gingival redness ( GI ) , Pre-cementing and Post-cementing sensitivenesss including gum tissue reactions, stain and integrating of the stuff were besides analysed and reported. All the patients were recalled for clinical scrutiny on a changeless clip period interval, like 30 yearss, 3 months, and 6 months. One twelvemonth scrutiny of the stuff was done on 15 patients. Researchers found that the on the job clip and setting clip of the stuff was found to be surprisingly inside bounds and it was an easy procedure of remotion of the cement every bit good. Though 4 patients reported ailments instantly about the post-cementing sensitiveness, but nevertheless it subsequently vanished within a month by an occlusive change ( S R Jefferies et al. , 2009 ) .
In a clip period of one twelvemonth no keeping failures or post-cementing sensitiveness was reported. All the Crowns and cementing procedure were rated Excellent by all the patients on the clinical tests. The Gingival redness, tooth sensitiveness, Pre- and Post-cementing job tonss were decreased during this clip period of survey. And this survey period besides revealed absence of secondary cavities and stain of the tooth border. Therefore, the new cement in the market ; Ceramir C & A ; B was found to be successful in the clinical tests, and was executing favorably for lasting cementation as a lute agent ( S R Jefferies et al. , 2009 ) .