REWETTING AGENTS ( water and hema )

The benefit of the wet bonding technique is derived from the ability of water to retain the collagen framework and intertubular porosity patent for subsequent infiltration of monomers. Many dentist, however, still dry the cavity preparation after rinsing the etching gel which results in collagen collapse followed by closing of the micro-pores in the exposed intertubular collagen .

 For better bonding to happen re-wetting the dried etched dentin with WATER and HEMA ( hydroxy ethyl methacrylate ) was demonstrated to restore the bond strength values and raise the collapsed collagen network to a level compared to a wet bonding technique.

                            REF: Dental Materials 15 (1999) 282 -295

SOLVENTS FOR DISSOLVING GUTTA PERCHA

1. eucalyptol
2. xylene/xylol
3.  methyl chloroform
4. tetrahydrofuran
5. methylene chloride
6.  halothane
7.  rectified turpentine  and
8.  orange solvent

REF: Endodontic Topics 2011, 19, 33–57

VARIOOUS ENDODONTIC IRRIGATION NEEDLES

 OPEN-ENDED NEEDLES

Flat end - NaviTip, Max-i-probe,Prorinse

Beveled end - Precision Glide Needle

Notched -Appli-Vac Irrigating Needle Tip

 CLOSED-ENDED NEEDLES

Side vented -KerrHawe Irrigation Probe

Double side vented -Endo-Irrigation Needle  

Multivented -EndoVac Microcannula.

                                  REF:JOE,2010

PHOTON INTIATED PHOTO ACOUSTIC STREAMING

Lasers are used to activate photosensitizers to destroy the bacteria and more recently to activate irrigation solutions by the transfer of pulsed energy. It appears that irrigation enhanced by ER:YAG laser light is effective in removing dentin debris and also in smear layer removal This might be achieved by the action of a pulsed ER:YAG laser via photon-initiated photo- acoustic streaming (PIPS) .

 PIPS functions via a direct shock wave, which is elicited from the specific model and settings of an Er:YAG laser used in this investigation . The unit was equipped with a novel 400-micro meter diameter radial and stripped tip. When activated at sub abalative parameters in a limited volume of fluid, the high absorption of the Er:YAG wavelength in water, combined with the high peak power derived from the short pulse duration that was used (50 microseconds), resulted in a photomechanical phenomenon.

                                                   REF: JOE  37,  7, 2011

PLATELET RICH FIBRIN ( FOR HEALING OF EXTRACTION SOCKET )

Healing of extraction sockets involves resorption ( both horizontal and vertical )and remodeling of the alveolar crest. Around 4mm of bone is lost. Most of the dimensional alterations take place in the first 3 months following tooth extraction. Alveolar ridge resorption and remodeling may affect implant placement.

Platelet-rich fibrin (PRF), is a second-generation platelet concentrate which consist of fibrin membranes enriched with platelets and growth factors that originate from anticoagulant-free blood sample. PRF looks like a fibrin network and leads to more-efficient cell migration, proliferation, and thus angiogenesis. PRF was initially used in implant surgery to improve bone healing.

                       REF : Journal of Dental Sciences (2011) 6, 116—122

PHOTON INTIATED PHOTO ACOUSTIC STREAMING

Lasers’ are used to activate photosensitizers to destroy the bacteria  and more recently to activate irrigation solutions by the transfer of pulsed energy . It appears that irrigation enhanced by erbium:YAG laser light is effective in removing dentin debris and also in smear layer removal This might be achieved by the action of a pulsed erbium:YAG laser via photon-initiated photo- acoustic streaming (PIPS) .

 PIPS  functions via a direct shock wave ,which is elicited from the specific model and settings of an Er:YAG laser used in this investigation . The unit was equipped with a novel 400-micro meter diameter radial and stripped tip. Subablative parameters (average power 0.3W, 20 mJ at 15 Hz) were used to produce a photomechanical effect seen when light energy is pulsed in liquid. When activated in a limited volume of fluid, the high absorption of the Er:YAG wavelength in water, combined with the high peak power derived from the short pulse duration that was used (50 microseconds), resulted in a photomechanical phenomenon.

                                                   REF: JOE  37,  7, 2011

RETROPLAST

Retroplast is resin based root end filling material .

Composed of BIS-GMA TEGDMA ,BIS –DMA.

Allows the proliferation of fibroblast along the root end thus enhancing periodontal ligament attachment.

                       REF: JOE ,34, 11, 2008.

GERISTORE

 Geristore is a dual cure , hydrophilic, nonaqueous  polyacid modified composite resin composed of fluoride releasing glass, mainly barium fluorosilicate, and a polymerizable organic matrix (Modified Bis-GMA, including 2-HEMA) combined with a photoinitiator.

Used as retrograde filling material for perforation etc….

Advantages of these materials

1. include insolubility in oral fluids,
2. increased adhesion to tooth structure,
3. dual cure effect,
4. low cure shrinkage,
5. low coefficient of thermal expansion,
6. radiopacity,
7. fluoride release, and
8. biocompatibility.

                                    REF: JOE  31, 3, 2005

MTA ( mechanism of action )

MTA basically both osteo inductive and conductive material,

Forms calcium hydroxide that releases calcium ions for cell attachment and proliferation.

Because of CH production it creates an antibacterial environment by its alkaline pH .

Modulates cytokine production .

Encourages differentiation and migration of osteo and odontoblast cells ,and

Forms HA (hydroxy apatite ) and provides a  seal.

                                       REF: JOE ,36,3, 2010

SERRATIOPEPTIDASE

Basically a proteolytic enzyme which has the following functions.

Eliminates post operative swelling and odema .

Enhances the action of antiobiotics.

Accelerates the liquefaction of pus and sputum.

Advised after traumatic extraction, I & D , periapical surgery etc.

  Available as 5 and 10 mg tablets.

HOW TO MANAGE A PATIENT IN DENTAL CLINIC

Listen to the patient completely of what is he saying.

Talk politely, and explain the condition of his oral cavity

Explain him the treatment options available for his condition.

Explain him each and every procedure that you are going to perform in his oral cavity.

Explain the function of each drug that you prescribed for him.

Always enquire about the patients post operative status when he comes for the next visit.

RETREAMENT FILES (R -ENDO AND M -TWO-R)

The R-Endo system, which consists of three size-25 instruments, the R1, R2 and R3 with 0.08, 0.06 and 0.04 tapers, respectively, is designed to work in each root canal third. .

The Mtwo-R file sizes 15 and 25, both with 0.05 taper, were designed with two blades, a tighter pitch that increases in the distal direction and an active point for easy penetration.

REF:IEJ ,2011

ACTIV -GP

Activ GP Precision Obturation System (Brasseler USA, Savannah, GA) is a new glass ionomer (GI )based obturation system. Inadequate bonding between GI and gutta percha  (GP) is a drawback with GI-based sealers . To enhance the GP-GI bonding, Activ GP has a 2 micrometre coating of GI particles on its surface; these particles-are also incorporated into the body of the cone.

The Activ GP System  is ISO sized and colored and is available in two types: a traditional design and an enhanced version (Activ GP Plus). Activ GP Plus uses calibration rings for easy depth measurement and a unique barrel handle which, when placed with an insertion instrument (transporter), facilitates easy placement into the canal .This Activ GP Obturation System delivers a true monobloc obturation result through a single-cone technique.Available in 0.4 and 0.6 percentage taper.

                                                          

                                                         REF: JOE, 34, 6, 2008.

RETREATMENT FILES ( PROTAPER SIZE AND TAPER )

1. ProTaper D1 file (30/09)
2. ProTaper D2 file (25/08)
3. ProTaper D3 file (20/07)

CCP-ACP

• Delivers supercharged calcium and phosphate ions to the enamel
• Binds readily to surfaces within the oral cavity and forms nanoclusters
• Helps maintain a state of supersaturation of calcium and phosphate at the tooth surface, enhancing
• Prevents and reverses early caries lesions often seen as white spots
• Works with fluoride in toothpaste to strengthen tooth enamel more effectively than fluoride alone
• Tooth paste with CCP-ACP are GC- tooth mouse and recaldent

                                   REF : journal of oral sciance- 2007

remineralization

INSTRUMENT REMOVAL SYSTEM

The Instrument Removal System (iRS) provides another mechanical method for the removal of intracanal obstructions such as silver points, carrier-based obturators or broken file segments.The iRS is indicated when ultrasonic efforts prove to be unsuccessful and may be used to remove broken instruments that are lodged in the straightaway portions of the root or partially around the canal curvature. The black instrument has an outside diameter of 1.00 mm and is designed to work in the coronal onethird of larger canals, whereas the red and yellow instruments have outside diameters of 0.80 and 0.60 mm, respectively, and can be placed deeper into more narrow canals. Each complete instrument is comprised of a color coordinated microtube and screw wedge Each microtube has a small-sized plastic handle to enhance vision during placement, a side window toimprove mechanics, and a 45° beveled end to "scoop up" the coronal end of a broken instrument. Each screw wedge has a knurled metal handle, a left handed screw mechanism proximally, and a solid cylinder that transitions into 0.02 tapered K-type file blades towards its distal end to facilitate engaging an obstruction

REF :JOE 2004.

ROTOSONICS (for post removal )

Rotosonics is a straightforward method to potentially loosen and remove a fully exposed post. The Regular Tip Roto-Pro bur (Ellman International; Hewlett, New York) is a highspeed, friction grip bur whose six faces are joined by six edges and when rotated one revolution, its edges produce six vibrations per revolution. When the instrument is rotated at 200,000 RPM, it produces 1.2 million vibrations per minute, . This instrument provides an inexpensive method to remove certain posts. The bur is kept in intimate contact with the obstruction and is generally carried counterclockwise around the post.

                                                                   REF:JOE,2004

ENDOX SYSTEM

The Endox system (Lysis S.r.I., Nova Milanese, Italy)

can sterilize the root canal by emitting high-frequency

electrical impulses. The manufacturer has claimed that

Endox could completely eliminate the pulp and bacteria

from the entire root canal system, including the lateral

canals. In addition, many other advantages have been

claimed—for example, the reduced treatment time and its

safety.

REF: Hong Kong Dental Journal 2004;1:52-7

PHOTO ACTIVATED DISINFECTION ( PAD )

In PAD, a photoactive agent (tolonium chloride,methylene blue , toulidine blue.) is applied to the infected area and left in site for a short period. The agent binds to the cellular membrane of bacteria, which will then rupture when activated by a laser light of appropriate wavelength (e.g. 635-nm radiation emitted by SaveDent; Denfotex Light Systems Ltd,United Kingdom). The light is transmitted into the root canals at the tip of a small flexible optical fiber that is attached to a disposable handpiece. The laser emits a maximum of only 100 mW and does not generate sufficient heat to harm adjacent tissues. Moreover the photo active agent ,( tolonium chloride )is biocompatible and will not stain dental tissue.

                           

                           REF : Hong Kong Dental Journal 2004;1:52-7

ELECTROCHEMICALY ACTIVATED WATER (ECA )

Electrochemically activated (ECA) water has been found to be biocompatible and effective in wound cleansing . Two types of ECA solutions can be produced from tap

water and a saline solution using a flow-through electrolytic module . The first is an anolyte that has antimicrobial properties, a high oxidation potential, and a pH value

ranging from 2 to 9. The other is a catholyte that acts like a detergent, has a high reduction potential, and is alkaline. Electrochemically activated water exists in a metastable state that contains a variety of free radicals, molecules, and ions. Biocidal agents, such as hydrogen peroxide, sodium hydroxide, and ozone, are also present in ECA water. After 48 hours, the solution will return to a stable inactive state. Electrochemically activated water is more effective than sodium hypochlorite solution in smear layer removal. Nevertheless, when the anolyte and catholyte were used individually to irrigate infected root canals, results of antimicrobial effectiveness tests were disappointing compared with 3.5% sodium hypochlorite.

                              REF : Hong Kong Dental Journal 2004;1:52-7

E.FAECALIS VS CALCIUM HYDROXIDE ( resistance features of E.faecalis )

 E. faecalis passively maintains pH homeostasis. This occurs as a result of ions penetrating the cell membrane as well as the cytoplasm’s buffering capacity.

E. faecalis has a proton pump that provides an additional means of maintaining pH homeostasis. This is accomplished by “pumping” protons into the cell to lower the internal pH.

At a pH of 11.5 or greater, E. faecalis is unable to survive .  However, as a result of the buffering capacity of dentin, it is very unlikely that a pH of 11.5 can be maintained in the dentinal tubules with current calcium hydroxide utilization techniques.

                                          REF: JOE — Volume 32, 2, 2006

Non instrumentation technique (NIT)

The non instrumentation technique (NIT), was introduced by Lussi et al., is a novel method of root canal debridement that uses the principle of controlled cavitation. The access cavity and root canal system are sealed off under reduced atmospheric pressure using specialized equipment. Rapidly alternating pressure fields (30-90 MPa, 25 Hz) are then generated, resulting in the production of macroscopic and microscopic cavitation bubbles (diameter, 5-50 μm) within the sodium hypochlorite irrigant . The vapor-filled bubbles then collapse, thereby creating hydrodynamic turbulence . Extrusion of irrigant is avoided because the pressure of the entire system is below atmospheric pressure . With a vacuum-filling method (using the same machine), the root canals can be dried and filled with a sealant . Nevertheless, NIT cannot enlarge the canal or remove the infected dentine.

                  REF: Hong Kong Dental Journal 2004;1: 52-7

BALANCED FORCE CONCEPT

 This technique was introduced by Roane et al. it involves

1 Placement into the canal and engagement of the file in the dentine by clockwise rotation  off not more than 90 degree and light inward pressure

2 Cutting and crushing of the dentine by anticlockwise rotation( around 180 -270 degree) and inward pressure matched to the applied torque in such a way that no inward or outward motion of the file results

3 Repetition of the preceding operation after the file has been placed more deeply into the canal

4 At the appropriate time, removal of the debris by clockwise rotation with outward pulling and cleaning with irrigant.

The superiority of this technique in comparison with the more common procedure of filing by successive inward and outward motions lies in its ability to enlarge curved canals to the required final diameter without transportation of the foramen, ledge formation or perforation.

                             REF: International Endodontic Journal (1998) 31, 166–172

CEROMER

They are composed of specially developed and conditioned homogeneous,

three-dimensional fine particle ceramic fillers of submicrometer size which are

densely packed (approximately 80% in weight) and embedded in an advanced

organic matrix with optimum light and heat curing potential.Ceromer technology is considerably more complex, containing polyfunctional groups. Such configurations provide the potential for creating a higher level of cross linking and more double-bond conversion, which results in the enhanced strength of the material.Due to their composition and structure, Ceromers combine the advantages of ceramics with those of state-ofthe- art composite resin technology. The ceramic (inorganic) phase of the material imparts durable aesthetic quality, abrasion resistance, and high stability. The resin (organic) phase of the material determines enhanced polishability, effective bond with the luting resin, low degree of brittleness.

MODIFIED IMPRESSION TECHNIQUE FOR CAST POST

After the post space preparation is completed. an elastomeric impression of the canal is made. To- prevent trapping of air bubbles in the impression, a syringe needle is held in the canal. As the elastomer is injected into the canal, air escapes through the needle. The needle is removed while pressure is maintained with the impression syringe. A new needle is used with each canal. A metal rod, coated with adhesive, is inserted into the canal for strength and then the tray with regular-bodied material is seated. After the impression has been removed, a temporary restoration is placed in the post. The remainder of the procedure is performed in the laboratory. The impression is poured in a dental stone. After the model is separated, the post and core are waxed directly on the stone die without lubrication .

                                  REF: JOURNAL OF PROSTHETIC DENTISTRY  

DENS IN DENTE ( DENS INVAGINATUS )

The dens invaginatus also called dens in dente, dilated composed odontoma or gestant odontoma, is a developmental disturbance resulting from invagination of the enamel organ toward the dental papilla before mineralization; it may be limited to the tooth crown or invade the root to affect the periapical region

Etiology: (i) delayed focal growth, (ii) stimulation in the area of the tooth bud and (iii) abnormal pressure on tissues surrounding the dental organ. The incidence ranges from 0.04% to 10% . Clinically, the crown of an affected tooth may appear normal or may have some alterations.

Oehlers classification:

Type I, characterized by a small invagination limited to the crown not extending beyond the cementoenamel junction;

Type II, the line delineating enamel invagination invades the root, yet is limited to it as a ‘cul-de-sac’ configuration, without reaching the periodontal ligament, yet it may communicate with the tooth pulp .

Type III, a severe form of invagination extending through the root and ending at the apical region without direct communication with the tooth pulp.

Radiographically, the roots present smaller dimensions with presence of a radiopaque formation with density similar to that of enamel, which is invaginated from the cusp through variable extents into the root. This invagination varies in shape and size, and may present a loop-like or pear-shaped configuration or a slightly radiolucent structure,  simulating a ‘tooth within a tooth’ .

                                                           REF: IEJ, 40, 146–155, 2007

GEMINATION AND FUSION ( DOUBLE TEETH )

Fusion and gemination are irregularities in tooth development and it is common to refer to these anomalies as ‘double teeth’. In gemination subdivision of the tooth bud is

incomplete, giving rise to two dental units, the width of which in the mesio-distal

dimension can be twice the dimensions of a single dental unit. This bifid tooth is considered as a single tooth unit, the number of teeth is normal and the double tooth shares a pulp chamber. By contrast, in fusion the originally separate tooth buds unite at the crown level (enamel) or at the crown and root levels (enamel and dentine). The number of teeth is ‘normal-1’ and the pulp chambers are separate. Both anomalies

occur more frequently in the primary dentition, particularly in the canine–incisor region.

They appear to follow preferential morphological patterns during formation, preferably

involving maxillary central and lateral incisors and mandibular lateral incisors and canines.

To explain the cause fusion, may be due to  lack of space as the cause of deep penetration of the dental follicles, while gemination can be interpreted as an attempt of a supernumerary tooth to form.

                                REF:IEJ, 41, 538–546, 2008

pulp stones ( classification & terminology )

True : Made of dentine and lined by odontoblasts.

False: Formed from degenerating cells which mineralize.

Free: Stone not related to pulp space wall, surrounded by soft tissue.

Adherent : Stone attached to wall of pulp space, not fully enclosed by dentine.

Embedded : Stone enclosed within canal wall, less attached than the above.

Denticle: An alternative term for pulp stone, more usually a calcification filled with epithelial remnants surrounded by odontoblasts.

Fibrodentine: Material produced by fibroblast-like cells against dentine prior to differentiation of a new generation of odontoblast-like cells.

Dystrophic Calcification: Inappropriate biomineralization of the pulp in the absence of mineral imbalance.

                                      REF: IEJ, 41, 457–468, 2008

ANTIBACTERIAL COMPOSITE ( MDPB containing composite )

 A new monomer 12-methacryloyloxydodecyl-pyridinium bromide (MDPB) was developed by combining the antibacterial agent quaternary ammonium and a methacryloyl group, incorporated into the resin of the composite .MDPB copolymerizes with other monomers after curing of the composite and the antibacterial agent is covalently bonded to the polymer network. The immobilized agent does not leach out from the material but acts as a contact inhibitor against the bacteria which attach to the surface.One of the advantages of bactericide-immobilized composite is the long-lasting antibacterial effect.

                            REF : Dental Materials 19 (2003) 449—457

SMART COMPOSITES (calcium and phosphate containing composites)

    Calcium and phosphate particles have been used as fillers in dental resins, and the resulting composite released calcium (Ca) and phosphate (P04) ions, which can form hydroxyapatite. However, the Ca—P04 composites had less flexural strengths. Such low strengths were insufficient to make these composites acceptable as bulk restoratives. Recently, nanoparticles of calcium phosphates were synthesized and incorporated into dental resins. The high surface area of the nanoparticles, along with  fillers, resulted in composites with stress-bearing and Ca and P04 releasing capabilities. Tetracalcium phosphate is another important compound used in bone cements, tissue engineering scaffolds, and dental composites. TTCP is the most alkaline among all Ca—P04 compound and, hence, is promising in buffering harmful acids and inhibiting tooth caries.

 pH of around  5.5—4 is considered to be cariogenic . Therefore, it is desirable for Ca—P04 composite to be “smart”, to increase the release of caries-inhibiting ions when ph drops.

 example : ariston phc 

                                 REF :  DENTAL MATERIALS 25 (2009) 535—542                                              

CLASSIFICATION OF ROOT CANALS

 Latrou classified root canals depending on the cross-section shape as: laminar or tubular (Latrou 1980).

 Laminar canals can be further divided into semilunar, ‘figure of 8’ or straight.

 Tubular canals can be divided in to circular, triangular or oval.

                                                    REF: IEJ, 38, 575–587, 2005

SYSTEM -B ( modification of vertical compaction )

The System B heat source (Analytic Technology, Redmond, WA, USA) was developed for use with a modified vertical condensation technique called the ‘continuous wave of condensation’ (Buchanan 1998), which was designed to simplify the vertical condensation technique. It is claimed by the manufacturer that the System B heat source allows sufficient heat for the apical GP to be softened and adapted to the irregularities of the intracanal anatomy. The technique is often used after preparation with nickel-titanium rotary files of greater taper. The heat source is an electric device that supplies heat to a plugger. Heat is applied at a prescribed temperature (200° C) for a short period of time as determined by the operator. By applying a constant source of heat to a prefitted gutta-percha cone, hydraulic pressure can be applied in one continuous motion for obturation

                                   REF: IEJ, 38, 218–222, 2005

LOW SHRINKAGE COMPOSITES ( SILORANE )

RESIN

The term “silorane” was introduced to represent hybrid monomer systems that contain both siloxane and oxirane structural moieties. Concerning the material properties of siloranes, the cyclosiloxane backbone imparts hydrophobicity  while the cycloaliphatic oxirane sites have high reactivity and shrink less during polymerization than methacrylates . some cyclosiloxanes have been reported to undergo cationic ringopening polymerization with volume expansion. Marginal integrity and microleakage of silorane-based restorative systems are reported to be superior to methacrylate-based systems.

INTIATING SYATEM

The development of a photoactivated silorane composite was realized with a three component initiating system comprising camphor quinone an iodonium salt and an electron donor. camphor quinone was chosen as a photo initiator to match the emission spectra of the currently used dental lamps. In this reaction path the electron donor acts in a redox process and decomposes the iodonium salt to an acidic cation which starts the ring opening polymerization process.

FILLER

Quartz particle of 0.5 micro meter has been used.

                                         Commercially available as P90 ( 3M  ESPE )

                                 REF: Dental materials ( 2007 )23, 1011–1017

                                          Dental Materials (2005) 21, 68 -74

COMPUTED TOMOGRAPHY (CT) in dentistry

Dental CT was introduced in 1987. In dental CT, axial scans of the jaws are acquired using the highest possible resolution, and curved as well as orthoradial multiplanar reconstructions are obtained. The coronal plane is not generally used for the scans in dental CT, since the metal artefacts from teeth fillings and other metal-dental work are frequent and appear in these sections. Using the axial planes, the occlusion plane will still have the artefact displayed, but the bone will be left undistorted.

Dental CT can be performed with a conventional CT, a spiral CT or a multislice CT scanner. The device should give high-resolution scans with a small focal spot and the acquired slices should be of 1.5mm thickness. The slower the rotation of the tube, the more detailed is the information gained. In order to achieve routine images of the jaws, a spiral scan technique of 1 s per rotation is valid, if small details need to be obtained for diagnostic purposes, then 2 s per rotation need to be used. 

  

TECHNIQUAL  DETAILS

The standard protocol for dental CT in the diagnosis of pathologic conditions is as follows: Incremental scan type, 1.5mm slice thickness, 1.0 table feed; 120mm field of view (for the mandible); 100mm field of view (for the maxilla); 2 s scan time; 512 matrix; 12 kV; 25–100m A; high-resolution edge enhanced filter, 20001400HU (Hounsfields units) bone window; mandible base and hard palate as scan planes . After the examination is completed, the axial slices are transferred to a workstation to perform multiplanar reconstructions; this is accomplished through dental software.

                                                 REF : Endodontic Topics 2004, 7, 52–72

MTA carrier system

1. lee pellet forming block. 
2. dovgan carrier system  with tip sizes 1.66mm,0.99mm,0.80mm respectively.
3. MAP SYSTEM- micro apical placement

                              REF: Endodontic Topics 2005, 11, 131–151

CRITERIA FOR IMMEDIATE IMPLANT PLACEMENT

1. Sufficient bone height, width, and density for stability of the implant at time of placement.

2. Sufficient mesial-distal, buccal-lingual, and interocclusal space for placement of an anatomic

restoration. If the space is less than 6 mm or if the opposing occlusion interferes with the provisional

restoration, then a 2-stage technique is used rather than the immediate provisionalization method.

3. The patient should have the expected compliance with the understanding to limiting chewing

to only the softest foods, preferably liquids, for up to 8 weeks. In addition, patients with excessive parafunctional habits are not provisionally reconstructed.

                                                 

                                                  REF:J Oral Maxillofac Surg 62:1131-1138, 2004

Avulsed tooth ( STORAGE MEDIA )

WATER
SALIVA
MILK
HBSS (hanks balanced salt solution)
EMDOGAIN
COCONUT WATER
EAGLES MEDIUM
GATORADE
SALINE......

                                       REF : BRITISH DENTAL JOURNAL

MTAD ( mixture of tetracycline acid detergent )

MTAD( mixture of tetracycline acid detergent ) is a solution composed of citric acid, doxycycline, and Tween 80, a detergent. It has been introduced by Torabinejad et al. and is marketed as Biopure (Dentsply, Tulsa, USA). it removes  smear layer adequately and have superior antimicrobial efficacy. The cytotoxicity of MTAD in vitro has been shown to be lower than eugenol, 3% hydrogen peroxide, calcium hydroxide, 5.25% NaOCl, CHX, and EDTA

                                        REF: Endodontic Topics 2009, 16, 27–63

MANAGEMENT OF VERTICAL ROOT FRACTURE

1. extraction .

2. The use of CO2 and Nd–YAG laser to fuse fractured roots was also tested

3. Bonding of the extracted fragments with adhesive resin cement was reported as being successful after intentional replantation of vertically fractured tooth.

4. In posterior teeth with multiple roots, hemisection or root amputation of the fractured root may be the treatment of choice, followed by a new restoration

                                   REF: Endodontic Topics 2006, 13, 84–94

Endotec II

Considering the ease and speed of lateral compaction as well as the superior density gained by vertical compaction of warm gutta-percha, Martin developed a device Called EndoTec II that appears to achieve the best qualities of both techniques.

In 1993, an Army group found they could measurably improve compaction while obturating a mandibular molar with a C-shaped canal by using the EndoTec in what they termed a “zap and tap”  maneuver: preheating the EndoTec plugger for 4 to 5 seconds before insertion (zap) and then moving the hot instrument in and out in short continuous strokes (taps) 10 to 15 times. The plugger was removed while still hot, followed by a “cold spreader with insertion of additional accessory points.

                                                   JOE — Volume 33, Number 5, May 2007

EMDOGAIN - a better root conditioner

Emdogain is made from an enamel matrix derivative secreted from Hertwig’s epithelial sheath during porcine tooth development. This enamel matrix derivative contains amelogenin as its major component in addition to other enamel matrix proteins such as enamelins, tuftelin, amelin, and ameloblastin. It serves as an important regulator of enamel mineralization and plays an important role during periodontal tissue formation,and also stimulates the regeneration of periodontal tissues including the acellular cementum, periodontal ligament fibers and alveolar bone by mimicking tooth development.

                                                 REF: JOE - 34, (1), 2008

PROBIOTICS ( in oral health )

Probiotics are described as live micro-organisms which when administered in adequate numbers confer a health benefit on the host (FAO/WHO). The term probiotic, meaning “for life,” is derived from the Greek language. It was first used by Lilly and Stillwell in 1965 to describe “substances secreted by one microorganism which stimulates the growth of another” and thus was contrasted with the term antibiotic

SUGGESTED MECHANISM

1)immune modulation, 2)modulation of gut immunological mechanisms, 3)mucin production, 4)down regulation of inflammatory responses, 5)secretion of antimicrobial substances, 6)competition with other flora, including potential pathogens by competitive blocking of adhesion sites at epithelial and mucosal surfaces,7) and inhibition of epithelial invasion by regulation of intestinal permeability, 8)inhibition of pathogens mucosal adherence and stimulation of immunoglobin A production.

                                          REF: Rev Clín Pesq Odontol. 2010

REVASCULARISATION ( treatment for immature avulsed tooth )

The avulsed tooth is replanted, and the canal is disinfected coronally through access opening with copious irrigation with 5.25% of sodium hypochlorite without mechanical instrumentation in the root canal. This is followed by the application of mixture of triple antibiotic paste (ciprofloxacin, metronidazole, and minocycline) inside the canal space. A blood clot is induced mechanically in the canal space from the coronal side by using a root canal file to the level of the cementoenamel junction to provide a scaffold for the ingrowth of new tissue. The coronal access is sealed by applying MTA at the level of the cervical area of the canal and a bonded resin coronal restoration above it.Several cases have shown continued root development similar to adjacent and contralateral teeth, and root wall thickening.

                                                             REF: Dental Traurnatologv 2011; 27: 46—54

BIOACTIVE GLASS (NOVAMIN )

BIOACTIVE GLASS containing calcium sodium phosphosilicate that the glass particles release calcium and phosphate ions intra-orally to promote  remineralization, Nourishes the teeth with essential calcium and phosphorous ions needed for the natural self-repair process of the teeth.

The silica containing Ca, PO and Na bind to the tooth surface

The Na buffers the pH above 7 (the pH is needed to be above 7 to allow for the precipitation of crystals onto the tooth surface)

The bioactive glass containing tooth paste ( NOVAMIN ) will release rapid and continuous deposition of a natural, crystalline hydroxyl-carbonate apatite (HCA) layer that is chemically and structurally the same as tooth mineral

when NovaMin contacts water or saliva (during tooth brushing, in this case), it releases fully-active ions of calcium and phosphorus. These ions are identical to those present in normal, healthy saliva .

bioactive glass containing toothpastes can be used for DENTINAL HYPERSENSITIVITY

                   

                            REF:  Australian Dental Journal 2008; 53: 268–273

LASER DOPPLER FLOWMETRY

INDICATIONS

Estimation of the pulpal vitality:  

Monitoring of reactions to local and systemic pharmacological agents (including local anaesthetic solutions) may be undertaken with LDF

MECHANISM

The original technique used a light beam from a helium neon (He Ne) laser emitting at 632.8 nm. Other wavelengths of semi-conductor laser have also been used: 780 nm and 780 820 nm.

Laser light is transmitted to the dental pulp by means of a fibre optic probe placed against the tooth surface. Two equal-intensity beams (split from a single beam) intersect across the target area. The scattered light beams from moving red blood cells will be frequency-shifted whilst those from the static tissue remain unshifted in frequency. The reflected light, composed of Doppler-shifted (light reflected by a moving object is Doppler-shifted) and unshifted light, is returned by an afferent fibre within the same probe to photo detectors in the flowmeter and a signal is produced. The photo- detectors convert the interference pattern arising from the mixing of shifted and unshifted light into a semi- quantitative measurement of blood flow, termed the Flux signal, which is measured in arbitrary units. The received signal is calculated with a preset algorithm in the LDF machine. The LDF output signal or Flux can be simplified as a function of the product of red blood cells’ concentration as well as their mean velocity. In fact, Flux is the number of moving red blood cells per second times their mean velocities.

                                               REF: IEJ, 42, 476—490, 2009

.

pulse oximetry ( in endodontics )

Principle

The oximeter applies a principle known as the Beer-Lambert law, which states that an unknown concentration of solute (hemoglobin) dissolved in a known solvent (blood) can be assessed by the light absorption of the solute.

Uses in endodontics

 To determine the vitality of tooth

Mechanism

A pulse oximeter uses a probe containing two light-emitting diodes (LED5): one transmits red light (approximately 660 nm), and the other transmits infrared light (900—940 nm) to measure the absorption of oxygenated and deoxygenated hemoglobin, respectively (it operates at 500 on/off cycles/s). Oxygenated and deoxygenated hemoglobin absorb different amounts of red and infrared light. This light is received by a photodetector diode connected to a microprocessor. The pulsatile change in the blood volume causes periodic changes in the amount of red and infrared light absorbed by the vascular bed before reaching the detector. The relationship between the pulsatile change in the absorption of red light and infrared light is assessed by the oximeter to show the saturation of arterial blood. It uses this information, together with known absorption curves for oxygenated and deoxygenated hemoglobin, to determine the oxygen saturation levels.

                                          REF: J Endo 2009;35:329—333

LEDGE (causes and management )

CAUSES

1. Incorrect or insufficient access cavity preparation
2. Incorrect assessment of root canal direction and curvature
3. Incorrect length determination of the root canal
4.  Re-treatment ,Occasionally, after removal of pre-existing filling materials or fractured instruments from the root canal, dentists may encounter ledges that had already been formed by previous attempts to negotiate the canal.
5. An attempt to negotiate a calcified or a very narrow root canal .
6. During post-space preparation after the completion of root canal treatment.
7. Use of non-precurved stainless-steel instruments in curved root canals
8. An attempt to retrieve or by-pass a fractured instrument or a foreign object (pin, post, etc.) from the root canal .

MANAGEMENT

         Copious irrigation with sodium hypochiorite and frequently replenished chelating     agents is required throughout the procedure.

Pre-enlargement of the canal coronal to the ledge is obtained by removing any curvature or obstructions.

The ledge is first probed with a precurved K-ffle ISO size 08 or 10. Hand instruments provide a better tactile sensation and are thus preferred to rotary instruments. In order to by-pass the ledge and gain access to the apex, the shortest instrument that can reach the level of the ledge should be used in a ‘watch-winding’ and gentle ‘picking’ motion of a short amplitude to look for a catch. Shorter instruments provide more stiffness and allow the clinician’s fingers to be positioned closer to the tip, resulting in a greater tactile sensation and control over the instrument. Directional tear-shaped rubber stops can be used on the file in order to orient its curvature.

The use of endodontic pathfinders and C-files that have originally been introduced for the initial instrumentation of the root canal can be very helpful when attempting to by-pass a ledge.

                                                REF: Endodontic Topics 2009, 15, 56—74

MELTON"S classification of "C" shaped canals

Category I: continuous C-shaped canal running from the pulp chamber to the apex defines a C-shaped outline without any separation.

Category II: the semicolon-shaped (;) orifice in which dentine separates a main C-shaped canal from one mesial distinct canal.

Category Ill: refers to those with two or more discrete and separate canals: subdivision I, C-shaped orifice in the coronal third that divides into two or more discrete and separate canals that join apically; subdivision II, C-shaped orifice in the coronal third that divides into two or more discrete and separate canals in the midroot to the apex; and subdivision III, C-shaped orifice that divides into two or more discrete and separate canals in the coronal third to the apex .

                                                 REF: JOE — Volume 33, Number 5, May 2007

APEX LOCATORS ( ROOT ZX)

The use of electronic devices to determine the WL was proposed first by Custer  in 1918, and the first EAL(electronic apex locator),was developed after Suzuki’s investigation of the electrical resistance properties of oral tissues. The first generation of EAL was resistance, based whereas the second generation was based on impedance. The main shortcoming of both types ,which corresponded to poor accuracy with electrolytes.

This  was overcome by the introduction of third-generation apex locators, such as the Root ZX (J.Morita Corp Tokyo, Japan). The Root ZX uses the “ratio” method to measure the root canal length. This method involves the measurement of impedance values at two frequencies (8 KHz and 0.4 KHz) simultaneously and the calculation of a quotient that expresses the position of the file tip in the canal . The Root ZX apex locator is considered to be the gold standard against which newer EALs are evaluated .

                                                   

                                                      REF: JOE Vohme 37, Number 5, May 2011

FLUORIDE IONTOPHORESIS

lontophoresis is a method of electrically transporting ionic particles into hard or soft tissue. Fluoride, which is such an ionic particle, is negatively-charged. Therefore, when an electrical potential is applied, fluoride ion would be repelled from the negative electrode (cathode) and attracted to the positive (anode).

The device comprises of an electrolyte ,

a positive terminal adapted for electrical contact with said body;

a negative terminal in electrical contact with said electrode; and

a current conduction means for permitting an intermittent direct current to flow between said positive and negative terminals, said current conduction means generating an intermittent direct current having a waveform which reaches a maximum level immediately after the current conduction is started and thereafter decays in time. 

THIS TECHNIQUE IS USED AS A TREATMENT FOR DENTINAL HYPERSENSITIVITY
                                                                     

                                                          REF : J Dent Res 63(6):897-900, June, 1984

casein phospopeptide-amorphous calcium phosphate (CPP-ACP)

 Casein phosphopeptides (CPP) stabilize high concentrations of calcium and phosphate ions, together with fluoride ions, at the tooth surface by binding to pellicle and plaque. Although the calcium, phosphate and fluoride ions are stabilized by the CPP from promoting dental calculus, the ions are freely bioavailable to diffuse down concentration gradients into enamel subsurface lesions thereby effectively promoting remineralization.

CPP containing the cluster sequence –Ser(P)-Ser(P)-Ser(P)-Glu-Glu- stabilize ACP(amorphous calcium phosphate) in metastable solution. Through the cluster sequence the CPP bind to forming nanoclusters of ACP preventing their growth to the critical size required for nucleation and phase transformation.

CPP-ACP forms nanocomplexes and bound tightly to Streptococcus mutans and plaque to produce a reservoir of bioavailable calcium ions.

.

CPP-ACP promotes the inhibition of enamel demineralization and enhance remineralization through the localization of bioavailable calcium and phosphate ions at the tooth surface.

can be used for incipient caries and for dentinal hypersensitvity.......... commercially available as  GC TOOTH MOUSE and  RECALDENT  

                                                               

REF: Australian Dental Journal 2008; 53: 268–273

sodium hypochlorite (naocl) - mechanism of action

1. saponification
2. neutralisation of amino acids 
3. chloramination                                    REF;CARLOS ESTRELLA , BR DENT J.      
    

CHEMICAL VAPOUR DEPOSITION (CVD)burs,manufacturing , applications and advantages

A vertical apparatus for hot-filament-assisted CVD deposition was used. Multiple small molybdenum rods of 1.0 mm diameter in vertical position were used as substrates. The top flat surfaces of the rods were polished, forming a right-angle relative to the rod longitudinal axis. Scratching with alumina powder of 9 micro meter particle size was used to enhance the nucleation. Tungsten wire of 0.2 mm diameter with several turns was used as the hot filament. The temperature of the hot filament and the temperature of the substrate holder were maintained at about 2500 K and 1000 K, respectively. A diluted gas mixture of CH4(methane) and hydrogen was used, at a typical pressure of 50 Torr.

Advantages and Appilications

The new diamond coated burs obtained by this process are adaptable to the handpiece of any ultrasonic instrument commonly used in dental offices for calculus removal.

The new dental diamond bur consists of a continuous film of diamond without a metallic binder between crystals, preventing the contamination of the tooth by metal ions usu- ally present in the binder matrix of conventional burs.

The CVD burs are also highly resistant to cutting and demonstrate efficient cutting ability and longevity. Some researchers demonstrated that CVD diamond burs used for cavity preparation .

                                                  REF: Braz Oral Res 2006;20(2)

                                                            Diamond and Related Materials 5(1996)857- 860

NANO IONOMER ( Ketac N 100 )

The nano-ionomer contains polyacrylic and itaconic acid copolymers necessary for the glass-ionomer reaction along with fluoroaluminosilicate (FAS) glass and water. The nano-ionomer also contains resin monomers like BisGMA, TEGDMA, PEGDMA and HEMA which polymerize via the free radical addition upon curing and it is stated that the primary curing mechanism is by light activation.

Primer contains water, HEMA, polyalkenoic acid copolymer, and photoinitiators. This material requires application of a primer but does not require a separate step for acid etching or conditioning

The nanofiller (5 nm to 25 nm) and nanofiller clusters (1 µm to 1.6 µm) are “loosely bound agglomerates of nanosized zirconia/silica” that compose approximately 60% of the glass component of Ketac Nano and make for higher filling loading. The manufacturer also reports that this radiopaque restorative material has fluoride ion fluid dynamics, like other glass ionomers, as well as higher strengths, enhanced esthetics, and better polishability than other RMGIs.

Indications  

1. Primary teeth restorations
2. Small class I restorations
3. Class III and class V restorations
4. Transitional restorations
5. Filling defects and undercuts
6. Laminate/sandwich technique
7. Core build-ups .

                                                                              REF: INSIDE DENTISTRY ,2009, 5(1)