PULP PROTECTION

                        

    This is a step in adapting the preparation for receiving the final restoration material.

     Sound dentin is the best barrier between a restorative material and pulp. So conservation of all sound dentin possible during cavity preparation should be beneficial.

     When the thickness of remaining dentin is minimal, heat generated by injudicious cutting can result in pulpal burn lesion, abscess formation or pulpal necrosis. So water or air spray coolant should be used with high speed rotary instrument. The remaining dentin thickness is measured by using dentinometer.

     Cutting of previously unexposed dentinal tubules will result in degeneration and death of affected primary odontoblast and their processes resulting in formation of dead tracts.

Other pulpal irritants are:

1.      Some ingredients of various materials

2.      Thermal changes conducted through restorative materials

3.      Forces transmitted through materials to dentin

4.      Galvanic shock

5.      Injuries of noxious products and bacteria through microleakage.

To protect the pulp from these kinds of irritation cavity liners, varnishes, cavity liner suspension, intermediary bases, cement bases, etc. are used.

                                               CAVITY LINER:

              Liners are volatile or aqueous suspension or dispersion of Zinc oxide or calcium hydroxide that can be applied to a tooth surface in a relatively thin film. A few microns to about a millimeter in thickness.

Liners Provide:

1. A barrier that protect the dentin from noxious agents.
2. Initial electrical insulator.
3. Some thermal protection.

           A traditional liner is used to medicate the pulp when suspected trauma has occurred. The desired pulpal effects include sedation stimulation, later resulting in reparative dentin formation. If the removal of infected dentin does not extend deeper than 1-2mm from initially prepared axial or pulpal wall usually no liner is indicated. If the excavation extends into or closes pulpal tissue, Calcium hydroxide, Zinc oxide Eugenol liner is used. There liners in thickness of 0.5mm or greater have adequate strength to resist condensation forces of amalgam and provide protection against short term thermal changes. Then should be approximately 2mm of bulk between pulp and metallic restorative materials.

          The ability of calcium hydroxide to stimulate formation of reparative dentin when it is in contact with pulpal tissue makes it is the material of choice in very deep excavations and known pulpal exposures.

                           CAVITY VARNISHES  

           There is no solution liner derived from natural gums, copal synthetic resins or rosin. When varnishes are applied to prepared tooth surface the solvent quickly evaporates leaving thin film of resinous materials (micro thickness). Two goals of varnish application are mandatory for complete seal. These are insoluble in oral fluids. These are applied to cavity wall using a small cotton pledge. Tooth varnishes usually applied just before the insertion of amalgam or cementation of cast gold restoration. These are the only material required in shallow preparations. These helps to prevent microleakage and reduce post operative sensitivity. These help to reduce pulpal irritation from leaking cement. They can be applied to enamel portion of the preparation. Tooth varnishes are not used under composite because solvent in the varnish reacts with resin component of composite and adversely affect the polymerization reaction. The free monomer of the resin can dissolve the varnish film. Varnishes will hamper the fluoride releasing property of glass ionomer cement. So they are not used under GIC also.

                                      CAVITY LINER SUSPENSIONS   

       These are suspensions of calcium hydroxide, zinc oxide which are particularly used under tooth colored restorative material. The film deposited by these materials is thicker. They will dissolve & disintegrate in oral fluids, thus allowing severe marginal leakage if they are brought in to cavosurface. The whitish color also affects the aesthetic value of restoration. So they are confined to dentinal wall only.

                                        

                                       INTERMEDIARY BASES.

          There is no clear distinction between intermediary bases & cavity liners. Two forms of intermediary bases used are calcium hydroxide &modified zinc oxide eugenol.

   Zinc oxide eugenol has topical anesthetic properties termed as obtudant effect. When a history of discomfort is found, zinc oxide intermediary base can be used.

    They are contraindicated under composite because they will affect the polymerization reaction. Calcium intermediary bases are used as indirect pulp capping agents, protective chemical barrier under filled &unfilled resins. Calcium hydroxide has no otundant properties.

                                         CEMENT    BASES

Cement bases are relatively thick materials placed under the restorative material which will provide chemical &thermal insulation. They should be capable of providing support to the restoration that is subjected to occlusal function. Four types of base material used are Zinc phosphate, Reinforced Zinc oxide eugenol, Glass ionomer cement and Zinc polycarboxylate.

The level to which the base is built should never compromise the desired tooth preparation resulting in inadequate restorative material thickness. Since cement base materials are subjected to stress during insertion of restorative material and also they are indirectly supportive of masticatory functions, they also require their own specific retention in the prepared cavity. Retentive grooves are made using round burs directly laterally in the dentin.

   In case of pin retained restorations, cemented pins are used for pulpal protection.

  These are different methods of pulpal protection.

Regardless of the material used protecting the pulp appropriately is mandatory for the successful restoration of the teeth

      

 REFERENCES-

                                  •Sturdevant’s Art&Science of Operative Dentistry

                                  •Principles&Practice of Operative Dentistry-Gerald T Charbeneau

                                  •Textbook of Operative Dentistry-Vimal Sikri

                                  •Textbook of Operative Dentistry-Satish Chandra

                                                               

Patient Complains of sensitive teeth on biting after Restoration. What to do?

A Pressure sensitive teeth after filling is an annoying condition. Many of us have such cases.Now lets see why this occurs and how to solve it.There are many causes for it lets see it one by one and consider the treatments
NOTE- In this article we will consider the causes of sensitive teeth on biting only (Pressure Sensitive teeth )  and not for Hot and cold sensitive or continuous pain after filling.

Cause 1. Composite restoration cases- if there is a bubble entrapment at the bonding interface of composite and dentin it will cause sensitivity. This occurs because the bubble shrinks during biting and applies pressure.
Solution-Remove the restoration and replace it with corrected one,use Single bond agents which does not require separate etching and boning.

Cause2. Deep caries.Dentin is too thin to protect the underlying pulp.
Solution - After removal of caries apply a nice layer of Calcium Hydrroxide/Dycal and cover it with temporary restoration. Ask the patient not to bite heavy on the particular tooth and recall after 4 weeks. Ask about the symptoms.If not resolved then let it be there for 4 more weeks.If resolved then replace the temporary restoration with permanent one.

Cause 3. Pulp hyperemia or thermal trauma during cavity preparation.
Solution- Remove the restoration and replace it with ZOE filling ,Relieve the tooth from occlusion, Start any NSAID for three days Recall after 3 weeks ask about symptoms, if relieved then replace the ZOE with permanent restoration.
[Additional]-Check your bur and replace it if its worn out, check for water spray of your handpiece it should be directed on the bur, Don't apply pressure will tooth preparation.

Cause 4. High point on the restoration.
Solution- Take an Articulating paper,Check for the high point and clear them. Recall after 5 days. If patient still have pain relieve the tooth from occlusion and start any NSAID.  

MI paste

MI Paste is a one-of-a-kind product that restores minerals and helps you produce saliva. It is the only dental product with RECALDENT™ (CPP-ACP), a special milk-derived protein that is a breakthrough in oral health care in helping to remineralize teeth.

MI Paste and MI Paste Plus with RECALDENT™ (CPP-ACP):
• Strengthens your teeth with tooth-replenishing calcium and phosphate
• Releases vital minerals into your mouth when and where they are needed
• Produces a saliva-like environment that maintains normal acid levels and healthy teeth
• RECALDENT™ CPP-ACP is milk derived with lactose content less than 0.01%.*
• Helps condition, protect and rebuild your tooth surfaces
• Is a water-based, sugar-free crème that comes in five delicious flavors

MI Paste with RECALDENT (CPP-ACP) fortifies your teeth to keep your smile vibrant for a lifetime.

* Casein phosphopeptides are derived from milk casein. Do not use this material on patients with a proven or suspected milk protein allergy and/or with a sensitivity or allergy to benzoate preservatives.

The MI Paste™ and MI Paste Plus™ Family

MI Paste is the only product for professional use containing the active ingredient RECALDENT™ (CPP-ACP), a special milk-derived phosphopeptide that binds calcium and phosphate to tooth surfaces, plaque and surrounding soft tissue. MI Paste is a water-based, sugar-free créme that is applied directly to the tooth surface or oral cavity. MI Paste with RECALDENT™ (CPP-ACP) restores the oral mineral imbalances that cause demineralization by replacing minerals while improving saliva flow and fluoride uptake as well as soothing sensitive surfaces - making it an ideal treatment for:

• Reversing tooth sensitivity and restoring enamel gloss after whitening procedures
• Relieving dry mouth caused by certain medications
• Reducing high oral acid levels from excessive soft drink consumption
• Reversing tooth sensitivity before and after professional cleaning
• Reducing high oral acid levels - sometimes a consequence of pregnancy
• Buffering acids produced by bacteria and plaque
• Regular conditioning during orthodontics, during and after bands or brackets have been removed, to prevent and reverse white spot lesions
• Providing a topical coating for patients suffering from erosion, caries and conditions arising from xerostomia

Use MI Paste™ -For white spot lesions; For desensitizing;During and/or after orthodontics; For medically compromised patients; For salivary deficiency/dry mouth; For patients with acidic oral environments; For erosion and gastric reflux; For patients with poor plaque control; For high-caries risk patients; To provide extra protection for teeth

MI Paste Plus offers the same benefits of MI Paste , but is enhanced with a patented form of fluoride (900ppm) to further promote remineralization and protect teeth from caries development. Since the fluoride acts in conjunction with RECALDENT™ (CPP-ACP), it is more effective than fluoride alone. MI Paste Plus is the only product that gives you the correct bio-available ratio of 5-calcium, 3-phosphate and 1-fluoride, which provides the ultimate enamel strengthening.

Specially designed for patients at high risk for dental caries and dental erosion, MI Paste Plus enhances mineral uptake without encouraging the formation of calculus. MI Paste Plus is safe and easy to use both in office and at home, and can even be claimed on a patient's insurance as fluoride treatment. It is also recommended for night use in patients with marked salivary dysfunction (dry mouth) due to medications, systemic illnesses, or salivary gland disease, because of the enhanced risk of mineral loss from dental caries or dental erosion.

Pulp Regeneration

Regenerative endodontics-The management of immature non-vital teeth following trauma or pulpal infection is a challenge. Traditional approaches can result in brittleness, with teeth susceptible to root fracture. This article discusses more biologically-based treatment approaches that offer regenerative possibilities and continued development of tooth structure.
The management of immature non-vital teeth following trauma, or pulpal infection secondary to caries, or dental anomalies such as dens evaginatus is a treatment dilemma and challenge for dentists. Traditionally, the treatment prescribed for immature non-vital teeth was thorough debridement of the root canal system followed by filling it with materials such as Ca(OH)2 in order to induce an apical barrier formation – i.e. apexification. In the last decade materials such as MTA have been used increasingly to create a barrier immediately. Following such treatments once a barrier is created, conventional obturation with gutta percha can then be performed in these teeth. These techniques however do not produce any increase in thickness of dentine or any increase in root length, and no qualitative or quantitative improvement of root dimensions is possible. Furthermore, studies have shown that intracanal Ca(OH)2 can induce brittleness of the tooth structure due to its hygroscopic and proteolytic properties, and following successful apexification these teeth are frequently susceptible to root fracture. Therefore, it is imperative that more biologically-based treatment approaches, which offer regenerative possibilities and continued development of tooth structure, be explored.
Pulp tissue in immature teeth with open apices has a rich blood supply, and given the right conditions, may have the potential for regeneration following pulpal damage. This is in fact not a novel concept in pulp biology, and had been discussed previously in the dental scientific literature by Nygaard-Østby as early as 1961.
Recent case reports have shown that immature non-vital teeth can demonstrate continued root development under favourable conditions that promote healing of apical pulp tissue. A classic case report by Iwaya and co-workers showed that five months after antimicrobial therapy, thickening of the dentinal walls and apical closure were seen in an immature second mandibular premolar with necrotic pulp. Other case series showed similar outcomes of continued maturation of root apices in teeth which had previously developed extensive periradicular lesions with sinus tract formation prior to treatment. In all these cases, some form of antimicrobial therapy, using antibiotic pastes and irrigation with sodium hypochlorite, was employed, serving as the disinfectant for the root canals. Also, in many of these cases mechanical instrumentation was not employed, and disinfection of the root canal was achieved purely through chemical means.
Various combinations of topical antibiotics have been proposed for use in the disinfection of root canals. The feasiblity for use of antibiotics as intracanal medicaments for disinfection of root canal spaces is supported by controlled animal studies carried out in dogs. One of the most well documented antibiotic combinations found to be effective against intracanal bacterial in infected root canals is the “3 mix-MP” triple antibiotic paste, which consists of ciprofloxacin, metronidazole and minocycline. In animal studies, the use of the “3 mix-MP” triple antibiotic paste was seen to be effective in the disinfection of immature teeth with apical periodontitis, and was able to induce apical closure of infected dog teeth with open apices. There are also case series in humans which have shown this method to be a viable alternative to the traditional use of Ca(OH)2 as the intracanal medicament of choice. The benefits are that the problems associated with alteration in the dentine structure and high pH of Ca(OH)2, which could potentially destroy the properties of multipotent cells associated with the continued root development in the apical papilla, can be avoided.
What the above-mentioned series of case reports also demonstrate is that vital pulp rich in regenerative potential is present at the most apical portion of the root, and that open apex non-vital teeth with periradicular pathology can still undergo apexogenesis. Successful removal of infected coronal pulp and disinfection of the root canal would provide a favourable healing environment for regeneration of pulpal tissue, thus allowing the vital pulpal cells at the apical papilla region to proliferate into the empty root canal space. This invariably further emphasises the importance of a sterile root canal as a pre-requisite for a conducive environment necessary for pulpal regeneration.
Clinical technique used for Regenerative Endodontic Therapy.
There are currently no standardised protocols for regenerative endodontic therapy (RET) in the treatment of non-vital immature teeth with wide open apices. Minor modifications to the procedures have been made by various groups who have carried out clinical case studies. The outline of the technique proposed in general is as follows:
All procedures are carried out under administration of local anesthetic and rubber dam isolation.
Pulpal extirpation and copious chemical irrigation of root canals with disinfectants such as 3% hydrogen peroxide or 2.5% sodium hypochlorite is performed for 30 minutes.
Minimal or no filing to the root canal is carried out to prevent further weakening of the existing dentinal walls.
The tooth is then dried and triple antibiotic paste is used as an intracanal medicament and sealed in the root canal. Caution should be exercised during the placement of antibiotic pastes to ensure that the application is below the cervical margins in order to prevent discolouration of the crown due to staining properties of minocycline.
The tooth is then sealed temporarily and a review is scheduled in 2-3 weeks to ascertain if the disinfection procedure has been successful. It is essential that disinfection of the root canal is carried out until there is no evidence of purulent discharge, sinus tract or infection, and a repeat of the disinfection process should be performed if the root canal is still not infection-free.
At the next appointment, the canals are re-irrigated copiously with saline. A sterile 23-gauge needle with a length of 2 mm beyond the working length is pushed past the confines of the root canal into the periapical tissues to intentionally induce bleeding into the root canal. The bleeding is then allowed to fill the root canal.
When frank bleeding is evident at the cervical portion of the root canal, a cotton pellet is then inserted 3– 4mm into the canal below the cervical margins and held there for about 7-10 mins to allow formation of a blood clot in the apical 2/3rds of the canal. This blood clot acts as a scaffold, rich in growth and differentiation factors, that are essential to aid in the ingrowth of viable tissue into the pulpal space and for wound healing processes.
The access is then sealed with materials such as MTA or Glass ionomer cements to prevent coronal leakage, extending about 4 mm into the coronal portion of the root canal
Periapical radiographs are then taken as baseline record. This is essential for comparison with future 6-monthly radiographs to ascertain continued root development and thus success of the treatment.
Indications/contraindications
As with all treatment, in order to increase success rates, case selection is paramount. This technique is indicated for all immature teeth which are non-vital, or partially necrotic teeth with open apex. There should not be concurrent signs of other pathological root resorption, eg. replacement root resorption which could otherwise affect the prognosis of the tooth. The safety of this technique however has not been evaluated for use in patients with medical conditions such as cardiac problems or bleeding disorders. Therefore, at this present moment, it would be prudent to avoid carrying out such procedures in medically compromised patients at risk of bacteremia or with abnormal bleeding tendencies.
advantages/disadvantages
Regenerative endodontic methods have the potential for regenerating both pulp and dentine tissues and therefore may offer an alternative method to save teeth that may have compromised structural integrity and hence poor long-term prognosis. The advantages of regenerative endodontic therapy are:
Shorter treatment time and therefore reduction in treatment fatigue, especially in young patients in which this clinical situation often presents.
Cost-effective due to the decreased number of visits.
Obturation is not required.
Achieves continued root development and strengthening of the tooth structure due to reinforcement of lateral dentinal walls and is therefore a more biological approach to treatment.
Success/survival rates
At this point in time, there are an inadequate number of studies in the dental literature looking at the success and survival rates of regenerative endodontic therapy procedures. However, from the limited evidence, successful treatment outcomes appear to be associated with the width of the open apices and young age of the patient. Most of the clinical evidence available is still at case report levels, and it may be timely to carry out prospective evaluative randomised clinical trials on the efficacy of medicaments used and treatment protocol employed as more evidence continues to be generated on this subject.
Conclusion
The potential scope of SCAP in continued root maturation in immature teeth should be exploited in the clinical management of non vital teeth with incomplete root development. This could potentially be a future clinical approach to replace the need and dependence of the dental profession on conventional endodontics that do not enhance the root structure, which means that such teeth remain prone to root fractures and hence usually have a poor long term prognosis.

DIRECT PULP CAPING-contraindicated in deciduous teeth

DPC- DIRECT pulp caping cant be done in a deciduous teeth ….reason being is that when you place ca(OH)2 on the pin point pulpal exposure(iatrogenic)….it causes necrosis of the pulp in tht pin point area….this invoke inflammatory reaction inside that pin point region of pulp….now this inflammation can either be restrictd to tht area only or it can spread to whole pulp….this inflammation can attract OSTEOCLAST cells which can cause internal resorption of deciduous tooth….(MC DONALD AVERY DEAN 8^th edition pg.408)

MTA after mixing

MTA burnisher and condensor

MTA Carrier

Used to carry MTA in case of root end filling surgeries.

Clinical Application OF MTA

MTA-Mineral Trioxide Aggregate

MINERAL TRIOXIDE AGGREGATE

• Mineral trioxide aggregate is a new biocompatible material with numerous exciting clinical application in endodontics.
• MTA prevents microleakage, is biocompatible and promotes regeneration of original tissues when placed in contact with periradicular tissues or dental pulp.
• Marketed as Gray MTA(GMTA) and White MTA(WMTA).
• The main reason for introducing WMTA as a substitute for GMTA was to provide a hue matched more closely to that of the colour of teeth as opposed to contrasting Gray colour of GMTA.
• COMPOSITION: MTA consists of fine hydrophilic particles. The material is primarily derived from calcium oxide ,silicon dioxide , and aluminium oxide .It also contains trace amount of silicon dioxide ,calcium oxide, magnesium oxide,iron oxide, potassium sulphate and sodium sulphate.
• Differences in FeO concentration is thought to be primarily responsible for variation in colour of WMTA (off white )in comparison to Gray MTA GMTA was un aesthetic in cervical area of anterior tooth .
• MANIPULATION: Each pack of MTA comes with pre measured unit dose of water for convenience in mixing. To use MTA simply pour the powder onto pad supplied ,add water and mix to working consistency. Water powder ratio should be 3:1 according to manufacturer. Variation on part of water powder ratio could account for increased solubility and porosity of material.
• SETTING REACTION:On addition of water compound in MTA react to produce calcium silicate hydrate gel that is calcium hydroxide contained in a silicate matrix.
• SETTING TIME : 2 hours 45 min – 4 hours
• pH :10.2 at start of mix ,rises to 12.5 after 3 hours. In experimental setting MTA is capable of maintaining high ph for long time. The high pH of MTA could be of clinical significance when used in apical barrier technique since alkalinity creates a favourable environment for cell division and matrix formation. Due to high ph MTA shows antibacterial action similar to calcium hydroxide.
• SOLUBILITY:It has been shown that set MTA’s solubility is a function of water powder ratio (for optimum properties recommended w/p ratio is 3:1) MTA is mainly composed of a insoluble matrix of silica gel that maintains its integrity even in contact with water.
• SEALING ABILITY/MARGINAL ADAPTATION: The sealing ability and marginal adaptation of MTA outperforms other material compared (amalgam, Super EBA IRM e.t.c. ). A stable barrier to bacterial and fluid leakage is one of the key factors in creating clinical success of root repair material.
• Clinically a barrier of 3-5 mm should be considered if root end surgery is a treatment option.
• MTA’ s sealing ability and better marginal adaptation is probably due to its hydrophilic nature, longer setting time and slight expansion when it is cured in moist environment. MTA contains 5% gypsum that expands during setting contributing to better adaptation .
• REGENERATIVE CAPABILITIES Regeneration has been defined as the replacement of tissue components in the appropriate location, in the correct amount and the correct relationship to each other. This means reformation of the bone in the surgical site, adjacent to fully reconstituted PDL, attached to newly formed cementum, over resected root end and root end filling material.
• Clinically a barrier of 3-5 mm should be considered if root end surgery is a treatment option.
• MTA is not an inert material in a simulated oral environment, it is “ BIOACTIVE ”.
• ADVANTAGES :Biocompatible;Non toxic;Non resorbable;Good marginal sealing;No irritation to surrounding tissues;Stimulates hard tissue formation ;moisture insensitivity;Radio opaque
• DISADVANTAGES: Difficult to manipulate;Longer setting time;Need two appointments.