Tuesday 31 May 2011

INTRAOSSEOUS DELIVERY SYSTEM (stabident and X- tip)

The X-tip system consists of two parts: a drill and a guide sleeve component . The drill has a special hollow needle which leads the guide sleeve through the cortical plate, where it is separated and withdrawn. The remaining guide sleeve is designed to accept a 27-gauge needle to inject the anesthetic solution. The guide sleeve is removed after the IO injection is complete.                                                                                               

Stabident system is composed of a perforator driven by a slow-speed handpiece and a solid 27-gauge wire with a beveled end that, when activated, drills a small hole through the cortical plate . The anesthetic solution is delivered to cancellous bone through the 27-gauge ultra-short injector needle placed in the hole made by the perforator.

                                                                    REF:JADA,2003,134,11

MTA as root canal sealer

Mineral trioxide aggregate (MTA) is used primarily to seal lateral root perforations, as a root-end filling material .MTA can also be used for a variety of other applications  including pulp capping and pulpotomy procedures

Newer developments of MTA include its use as a root canal sealer. Currently, three MTA sealer formulations are available; Endo-CPM-Sealer ,MTA Obtura and ProRoot Endo Sealer.

The composition of CPM sealer after mixing is reported to be 50% MTA (Si02, K20, A1203, SO3, CaO and Bi203), 7% Si02, 10% CaCO3, 10% Bi203, 10% BaSO4, 1% propylene glycol alginate, 1% propylene glycol, 1% sodium citrate and 10% calcium chloride .

MTA-Obtura is a mixture of white MTA with a proprietary viscous liquid.

ProRoot Endo Sealer is calcium silicate based endodontic sealer. The major components of the powder of ProRoot Endo Sealer are tricalcium silicate and dicalcium silicate, with inclusion of calcium sulphate as setting retardant, bismuth oxide as radiopacifier and a small amount of tricalcium aluminate.

Sealers based on MTA have been reported to be biocompatible, stimulate mineralization and encourage apatite-like crystalline deposits along the apical and middle thirds of canal walls .

                                                                                REF;IEJ,2011,44(9)

Endovac

The EndoVac is a new irrigation system. A delivery/evacuation tip is attached to a syringe of irrigant and the high speed suction of the dental chair . A small tube attaches either a macro- or microcannula to the suction. The delivery/evacuation tip places irrigant in the chamber and siphons off the excess to prevent overflow. The macrocannula is plastic with an open end that measures International Standards Organization (ISO) size 55 with a .02 taper. The microcannula is stainless steel and has 12 small, laterally positioned, offset holes in 4 rows of 3, with a closed end measuring ISO size 32 . As these cannulas are placed in the canal, negative pressure pulls irrigant from a fresh supply in the chamber, down the canal to the tip of the cannula, into the cannula, and out through the suction hose.

                                                                                          REF: JOE ,2007,33.

APEXUM procedure

This procedure is based on a device that removes the chronically inflamed periapical tissues through a root canal access by a procedure that is minimally invasive compared with open-flap apical surgery

 Apexum  instrument kit consists of

The Apexum kit consists of two devices, the Apexum NiTi Ablator and Apexum PGA Ablator.

The Apexum NiTi Ablator consists of a specially preshaped Nitinol wire. One end is bent and is designed to enter the periapical tissues through the root canal and apical foramen, whereas the other end has a latch-type connector to allow its attachment to a low-speed contra-angle handpiece. The bent part is initially concealed in a straight super elastic Nitinol tube that serves as a sheath allowing its introduction up to the apical foramen. When pushed, the wire emerges from its sheath and through the apical foramen and resumes its preshaped form. The special retrograde design of the bent part allows it to rotate in the periapical soft tissues at 200 to 250 rpm and coarsely grind them while being deflected from the surrounding bone.

The second device is the Apexum PGA Ablator, built from a Nitinol shaft. It has a bioabsorbable  filament is attached, which is designed to enter the periapical bony crypt and rotate at 5,000 to 7,000 rpm, turning the tissue that was initially minced with the NiTi Ablator into a thin suspension that may be flushed through the root canal.

                                                                                    REF: JOE, 2009,35(2).

Monday 30 May 2011

CALCIUM HYDROXIDE ( antibacterial activity and mineralisation mechanism )

  1. Calcium hydroxide is antibacterial depending on the availability of free hydroxyl ions .
  2. Denaturation of proteins ,DNA break down and lipidic peroxidation are main actions responsible for antimicrobial activity of calcium hydroxide
  3. It has a very high p11 (hydroxyl group) that encourages repair and active calcification. There is an initial degenerative response in the immediate vicinity followed rapidly by a mineralization and ossification response .
  4. The alkaline pH of calcium hydroxide neutralizes lactic acid from osteoclasts and prevents dissolution of mineralized components of teeth. This pH also activates alkaline phosphatase that plays an important role in hard tissue formation .
  5. Calcium hydroxide activates the calcium-dependent adenosine triphosphatase reaction associated with hard tissue formation .
.
                                                                                    REF: JOE, 2009, 35 (4)

BUC ultrasonic tips

BUC-1

The BUC-1 can be used for gross dentin removal, moving access line angles, cutting a groove in the mesial access wall to drop into MB2 canals, and for quickly and carefully unroofing pulp chambers. Its radiused tip geometry also allows effortless entry into each canal orifice and facilitates the creation of a smoothly troughed surface, which is helpful in finding reclusive MB2 canal

BUC-2 and BUC-2A

The BUC-2, with its disk-like radiused tip, can be used to smoothly and safely plane attached pulp stones from the pulp chamber floor without scoring it. In molars, it can be used to horizontally smooth the pulp chamber floor without cutting past it to get to the darker colored dentin. The smaller version BUC-2A has a 1.0mm diameter and can be used for corners of molar access prep and bicuspid access prep.

BUC-3

The BUC-3 is an extremely active instrument with a sharp tip. It is used for chasing canals halfway up a root or for digging around a post or carrier-based obturator to remove it. It has a water port placed near the cutting surface of the tip for increased washing and cooling of the operative site.

RESILON-EPIPHANY SYSTEM

Resilon

organic part: thermoplastic synthetic polymer – polycaprolactone,

inorganic part: bioactive glass, bismuth oxychloride, barium sulphate

Epiphany (sealer)

organic part: BisGMA, ethoxylated BisGMA, UDMA, hydrophilic
difunctional methacrylates

inorganic part: calcium hydroxide, barium sulphate, barium glass,
bismuth oxychloride, silica

Resilon Primer
sulfonic acid terminated functional monomer, HEMA, water.

                                                                            Ref-Adv in med science-2006

monoblock

The term monoblock, literally meaning a single unit,

Primary monoblock.- A primary monoblock has only one interface that extends circumferentially between the material and the root canal wall. Ex - hydron and MTA obturation

Secondary Monoblocks
Secondary monoblocks are those that have two circumferential interfaces, one between the cement and dentin and the other between the cement and the core material. Ex – post luting and conventional sealer ,gutta percha obturation

Tertiary Monoblocks
Tertiary monoblocks are those in which a third circumferential interface is introduced between the bonding substrate and the abutment material. Ex  -  Activ Gp  , which has an external Gic coating.

                                                                                     
                                                                                REF: JOE,2007,33,(4).

Sunday 29 May 2011

composites-repairing technique

1) sand blasting with aluminium oxide particle. ( 30 micro meter ).

2) etching with HF acid .

3) application of silane coupling agent.
                                 
these techniques improves the bond strength while repairing composites,however depending on the type of the composites ,the above one of the methods can be used

                                                                                      REF:DM,2011,27,701-709

DIAGNODENT (laser induced fluroscence)

For early caries detection, laser-induced fluorescence (LIF) has proven its effectiveness. Fluorescence is the emission of visible light by a substance that has absorbed light of a different wavelength . LIF yields information on the metabolic state of cells or presence of micro-organisms depending on the nature of the fluorescent molecule (co-enzymes or porphyrin metabolites, respectively). The tissue examined is excited with a specific laser wavelength that generates a maximum fluorescence response. After a few nano/micro-seconds, the tissue will de-excite and emit light at a wavelength larger than the original excitation wavelength. The so-called ‘DIAGNOdent’ (Kayo, Biberach, Germany) is a laser-induced caries-detection device that is equipped with a semiconductor laser (655 nm) as excitation source. The laser light is emitted from the tip of the handpiece that also captures the fluorescence reflected from the tooth surface, by means of a photodiode (680 nm) in combination with a long-pass filter that absorbs the backscattered excitation. The device quantifies the fluorescence intensity that is subsequently converted to a calibration standard, ranging from 0 to 99.

                                                                                         REF: JR OF DENT, 2011.

Saturday 28 May 2011

Autotransplantation (remedy for missing tooth)

Autotransplantation is defined as the transplantation of teeth from one site to another in the same individual into extraction sockets or surgically prepared sites . prognosis of autotransplantation depends on a number of preoperative and postoperative factors including root development, position of the tooth and surgical technique. proper manipulation of the donor tooth and recipient site under favourable preoperative, surgical and postoperative conditions ensures survival of the cells of the periodontal ligament and promotes the reformation of a normal supporting apparatus. Recent advances in procedures and materials have resulted in the development of autotransplantation for the treatment of missing teeth.

Autotransplantation of premolars to replace missing teeth in young individuals has been better substitution method with potential for bone induction and reestablishment of a normal alveolar process . The most successful procedure involves transplanting premolars before the root is fully formed. This way, pulp revascularization and health can be preserved, and the tooth retains the potential to erupt and induce alveolar bone growth.


                                                                                          REF: IEJ,2011

self adjusting file (SAF)

SAF system, was recently introduced by ReDent-Nova . The SAF is a hollow file designed as a compressible, thin-walled, pointed cylinder 1.5 mm in diameter and composed of 120-micro meter-thick nickel-titanium lattice. The SAF is operated using a trans-line (in-and-out) vibrating handpiece head (RDT3, ReDent-Nova) that generates 5,000 vibrations per minute at an amplitude of 0.4 mm. This innovative file is claimed to adapt itself to the 3D canal morphology both longitudinally and cross-sectionally.

                                                          REF. JOE 2011,37,881-887.

Friday 27 May 2011

enamel microabrasion

 The procedure was introduced by mckloskey. It is a technique to remove super- ficial enamel discoloration earlier 18% hydrochloric acid and laboratory pumice was used. By a combined chemical action of the acid and the abrasive effect of the pumice, a superficial enamel layer was removed improving the color of the enamel.  Later a compound called PREMA composed of HCL and silica carbide was used for removal of surface discoloration of enamel.                                                                                                                                                                                                                                                                     

Thursday 26 May 2011

fibre posts

introduced by durret et al... composed of glass,graphite,polyethylene,fibre,quatrz,carbon,embeded in a resin matrix......

esthetics,modulus of elasticity similar to that of dentinare some of its advantages...