Role of Zinc in Silver Amalgam

Role of Zinc in Silver Amalgam 

Zinc as such does not participate in the amalgamation process or in the setting reaction of silver amalgam alloy with mercury during and after the completion of the restoration process. 

CBI Books Head of Dental Department AIIMS-Patna for Corruption Charges

The Central Bureau of Investigation (CBI) has filed an FIR against former Head of the Dental Department of All India Institute of Medical Sciences (AIIMS)-Patna, Dr. Shailesh Kumar Mukul. He is accused of resorting to “unlawful means in conspiracy with others” during the 2013 and 2019 period.  

Coronavirus Disease: Seven Essential Norms You Should Follow to Help Yourself during Home Quarantine Period

Coronavirus Disease-COVID-19: Seven Essential Norms You Should Follow to Help Yourself during Quarantine Period

The following category of people should stay at home under home quarantine status. This category includes a person with suspected coronavirus infection, those under investigation but not needing hospitalization. Also, the one who had had confirmed coronavirus infection was hospitalized earlier but now has been discharged and medically stable. These people should stay at home under quarantine conditions.

Dental Amalgam Alloys

Dental Amalgam 

In this section, we shall discuss the composition, type and properties of the dental amalgams alloys used for restoration purpose in posterior teeth as per following format. The source of these notes, MCQs and explanation is Phillips’ Science of Dental Materials, 12th Ed and Sturtevant’s Art and Science of Operative Dentistry.

Why is Zinc Not Added to Dental Amalgam?

Why is Zinc Not Added to Dental Amalgam?

Zinc as such does not participate in the amalgamation process or in the setting reaction of silver amalgam alloy with mercury during and after the completion of the restoration process.

Covid 19: Test Yourself-How Much Do You Think, You Know Coronavirus?

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Indian Prosthodontic Society holds its 46th conference in Mangalore

Indian Prosthodontic Society (IPS) holds its 46th conference in Mangalore on 15th November 18.

19th National PG Student Convention of Indian Prosthodontic Society will be held in Gujarat

The 19th National PG Student Convention of Indian Prosthodontic Society is scheduled to be held from 5-7 April 2019 at Gandhinagar, jointly by Gujarat IPS State branch and Narsinhbhai Patel Dental College & Hospital, Sankalchand Patel University, Visnagar, Gujarat.

 

Local Anaesthesia

Local anaesthesia means a no pain sensation in a particular area supplied by a specific nerve. The correct term is local analgesia but commonly not used? It is given with the help of 2 ml or 5 ml single use disposable syringes. 
The anaesthesia is an inseparable part of surgery. It provides maximum patient comfort and cooperation. Without anaesthesia, the advancement in surgeries could not have been achieved. In 3rd molar surgery a patient may opt for general anaesthesia or local anaesthesia. The local anaesthesia may be supplemented with sedation for increased comfort. 
 

Advantages of Local Anaesthesia 

 
Local anaesthesia has the following advantages over general anaesthesia. 

1. It is safe, efficient and predictably effective in almost all patients. 
2. It is inexpensive. 
3. It is easy to administer. 
4. For healthy patient, no monitoring is needed by equipment 
5. The patient does not lose consciousness with an intact gag reflex during anaesthesia. 
6. Procedures under local anaesthesia, hospitalization is not needed, therefore, for patients’, it is convenient. 
7. To administer local anaesthesia, no preoperative fasting is required. 
8. A patient can be discharged immediately without waiting for recovery or an escort. 

 

Limitations of Local Anaesthesia 

 
Despite the huge number of advantages, the local anaesthesia does have certain disadvantages. They are as follows. 

1. It cannot be used in a non-cooperative patient; for example, younger children. 
2. It cannot be used in a patient with fear of needles. 
3. It cannot be used in an anxious or nervous patient. 
4. It is only suitable for short procedures which are of less than 30-minute duration. 
5. It cannot anesthetize the locally inflamed tissues. 

 

Composition of Local Anaesthesia 

 
The local anaesthetic solutions mainly contain the following contents. 

1. Local anaesthesia base. 
2. Hydrochloride salt for solubility and stability. 
3. Buffering agents. 
4. Preservatives; e.g., Methyl Paraben 

 

How does local anaesthetics prevent the conduction of dental pain? 

 
Local anaesthetics inhibit the generation of electrical impulses and their conduction along the neuronal axon membrane, by reversible blockade of sodium ion channels. 
There is a continuous imbalance of sodium and potassium ions between the cytoplasm of neurons and the intercellular fluid. This is maintained at about 25 times more potassium intracellularly and 15 times more sodium in interstitial space. 
 

Mechanism of action 

 
The molecule of local anaesthetic agent enters the neural cell through neurilemmoma from interstitial fluid by a simple diffusion process. Then in the acidic environment of a neural cell, it breaks itself in its components and acts on the sodium influx gate and blocks it, thus blocking the generation of action potential, thus blocking signal conduction along the nerve cell membrane. The local anaesthesia cannot act on sodium influx gates from outside the nerve cell. It must enter the nerve cell. 

Question: What happens when the area surrounding the nerve gets inflamed?  

Once the tissue is inflamed, the interstitial fluid becomes acidic in nature. In an acidic environment, the local anaesthetic molecule breaks down. A broken local anaesthetic molecule cannot pass through the cell membrane by a simple diffusion process and thus cannot produce its effect.

 
This is the reason a local anaesthetic cannot produce its effect in an inflamed tissue or is not so effective in an inflamed area. 

Question: Why does LA not function efficiently in an inflamed environment?   

Answer: The molecule of local anaesthetic agent enters the neural cell through myelin sheath from interstitial fluid by a simple diffusion process. Then in the acidic environment of a neural cell, it breaks itself in its components and acts on the sodium influx gate and blocks it, thus blocking the generation of action potential, thus blocking signal conduction along the nerve cell membrane. The local anaesthesia cannot act on sodium influx gates from outside the nerve cell. It must enter the nerve cell.

    
Question: What happens when the area surrounding the nerve gets inflamed? 

  
Once the tissue is inflamed, the interstitial fluid becomes acidic in nature. In an acidic environment, the local anaesthetic molecule breaks down. A broken local anaesthetic molecule cannot pass through the cell membrane by a simple diffusion process and thus cannot produce its effect.

  
This is the reason a local anaesthetic cannot produce its effect in an inflamed tissue or is not so effective in an inflamed area.    
  
 
 
 
 

What should you look for before starting a crown preparation?

So, you are ready to start your crown work for the patient who is eagerly waiting to regain the lost functional ability, phonation and aesthetics. The functional ability, aesthetic value, speech enhancement and self-confidence of the patient will enhance when you look for the following anomalies in the oral cavity and rectify them, before the commencement of the crown preparation. You can make your crown & bridge without giving a dam for these factors, and get the quick bucks. But, it would be a good idea to consider them before you jump on for crown preparation part. And believe me, in long run, you will gain the faith of your patient, converting into your most reliable source of referral and image builder. These factors are given below:

• General overall health of the oral cavity
• Expectations of the patient
• Extremely tilted teeth
• Mobile teeth
• Type of occlusion
• The type of crown you want to fabricate for your patient

When we start examination, we look for the general health of the oral cavity. Is it healthy? Does the oral hygiene acceptable? Does the periodontal status of the tooth concerned adequate? Is the tooth tilted, rotated, supra or infra erupted? Does the patient need oral prophylaxis? What are the other systemic diseases the patient is suffering with; for example, cardiac, endocrine, orthopaedic, and physiological?  If any of the answer is yes, then the dentist needs to take care of them first, before the commencement of the crown preparation. Of course, few chronic diseases cannot be cured but they should be kept under control by the patient’s’ physician.

That preparatory phase, the phase that involve the work done inside the mouth so that the longevity of the prosthesis remains satisfactory, includes the scaling and root planing, the removal of hopeless mobile teeth, orthodontic correction of tilted tooth, and occlusal surface adjustment of the supra erupted tooth. The other decayed teeth should be appropriately restored.

You should also know that what type of crown you plan to provide or what type of crown the patient is wishing for? What are the expectations of the patients from a particular type of crown? Will the patient understand the significance of the particular type of crown? Does patient understand the inherent drawbacks of that particular crown? Does patient know and ready to accept the post insertion maintenance care?

The other consideration is the type of occlusion in a patient. Is it canine protected or group function? Will you be needing to alter it for the betterment of the function and longevity? Does patient has any TMJ issue?