Introduction to Third Molar Surgery: Part 3-Classification of Impaction

Classification of third molar impaction is done to facilitate the communication between clinicians, for record keeping that may be used for audit research purposes.    

Introduction to Third Molar Surgery-Part 1

The third molars are the most common teeth that are found to be impacted. This article will provide and introduction to this topic. The difference between simple and surgical extraction along with the aetiologies and frequency of third molar impaction are explained in a simple way.

Extensive Facial Injury in an Unconscious patient: Case Discussion & Treatment Planning

This case presentation is about the emergency management of a traumatized patient. The questions related with this type of accidental cases may be asked in part one examination. I can guarantee you that at least once, you will be asked about the management of an accident case in viva voce session of ADC part 2 practical examination. You are supposed to prepare a treatment plan for this patient. 

If you wish, you can submit your treatment plan in the comment box. If need arises, you will get a positive response.

 

Case Description:

This male patient, in mid 40s was brought to the emergency room with the condition shown in the picture. He was unconscious with a GCS score of three and without any history. He was intubated to maintain airway in the emergency room. As a member of the emergency management team, you were called upon to perform your role. You were the first person to reach the emergency room. While other members are on their way, what will you do to manage this case? 

 

Extensive facial injury
Extensive facial injury of a male patient of mid 40s.

 

Do not copy or re-use this photograph.

Oral Manifestations of Leukaemia

The oral manifestation of leukaemia can be summarized as follows.

In acute leukaemia- localized or generalized gingival hyperplasia is generally observed. It mainly affects the interdental papillae and the marginal gingiva. 

Contact Point/Area of the Teeth

The proximal contact point or the area refers to the surface point or area where the proximal surfaces of neighbouring teeth come in contact. Contact point/area is usually found in the occlusal one third of the natural crown of the most of the teeth.  

Can clothe masks be a substitute for N95 masks?

Can clothe masks be a substitute for N95 masks?  

The researchers at the University of Chicago performed a study to check the purification ability of the cloth masks. They made masks by joining one layer of tightly woven cotton sheet1 and two layers of polyester-spandex chiffon2, which is a fabric commonly used in evening gowns. These masks filtered out 80% to 90% spray particles ranging from 10 nanometres to 6 micrometres in diameter at normal human respiratory flow rate and volume.  

 

Diabetes Mellitus

Article written by 

Dr. Neha Rai 
MBBS, MD SR AIIMS Patna

Diabetes Mellitus refers to a group of common metabolic disorders that share the phenotype of hyperglycaemia and are caused by a complex interaction of genetics and environmental factors. It is very different from Diabetes Insipidus. Diabetes Insipidus is a syndrome characterised by the production of abnormally large volumes of dilute urine due to decreased secretion or action of Vasopressin, a hormone secreted by the posterior pituitary gland. 

The pathogenic process leading to hyperglycaemia is the basis for classification of diabetes mellitus into several types. Age or insulin dependence are no longer the criteria for differentiation. Type I and Type II are the two broad categories. In Type I DM there is destruction of pancreatic β cells and insulin deficiency resulting from autoimmune β cell destruction. Type II DM is characterised by variable degree of insulin resistance, impaired insulin secretion, excessive hepatic glucose production and abnormal fat metabolism. 

Bio-medical Waste Management

The biomedical waste management in India should be the burning and worrisome topic for the public as well as hospitals and health care service providers. Bio-Medical Waste (Management and Handling) Rules 2016 and further amendments in 2018 and 2019 have made enough provisions to handle all the biomedical wastes by any entity involved in anything related with health care provision. This includes, hospitals with only OPD facilities, hospitals with indoor facilities, blood donation camps, free health camps, medical services being provided in the field excluding the active war zones as well as the ships in the international water with Indian registration. 

The categorization of all biomedical wastes into four color categories namely yellow, red, white, and blue made the segregation easy and practical. It does not specifically say anything about the rules and regulations to be followed in reference to COVID-19. But when, the proper biomedical waste management protocols, standard precautions also known as universal precautions and the latest guidelines issued for the control of spread of Covid-19 by MoHFW are put together; we find ourselves equipped with enough tools to deal with all types of wastes and infections. 

We shall read more about the Bio-medical Waste (Management & Handling) rules 2016 and further amendments in 2018 & 2019 in further articles. 

Pontic Design in Prosthodontics

The pontic, \pŏn΄tĭk\, is an artificial tooth on a fixed partial denture that replaces a missing natural tooth, restores its function, and usually restores the space previously occupied by the clinical crown. An ideal correctly designed posterior pontic should have the following features.

  • All surface should have convexity with proper finish.
  • The contact with buccal contiguous slop should be minimal (pinpoint)) and with pressure free (modified ridge lap).
  • Buccal and lingual shunting mechanism should conform with those of the adjacent teeth.
  • Occlusal table should be in functional harmony with the occlusion of all of the teeth.
  • The overall length of the buccal surface should be equal to that of the adjacent abutment teeth or pontic.

The Pontic design can be classified into two types.

A. Pontic having mucosal contact

  1. Sanitary/Hygienic/Fish-belly and
  2. Modified sanitary type

B. Pontic with no mucosal contact     

  1.  Saddle/Ridge lap
  2.  Modified Ridge Lap
  3.  Conical
  4.  Ovate

 

Sanitary or Hygienic Pontic or Fish-Belly 

Sanitary pontic makes no contact with the edentulous ridge. It is made in an all-convex configuration, faciolingually and mesiodistally. The space between the pontic and the mucosa should be 2 or 3 mm[2]. It is most commonly used in mandibular molar replacement. It has the advantage of providing good access for maintaining hygiene with the disadvantage of poor esthetics.

Image of sanitary pontic design
Sanitary pontic design-note the convexity at cervical region

Modified Sanitary

The tissue facing surface of the modified sanitary design pontic has a hyperbolic parabola. The pontic is designed as a concave archway mesiodistally while the under surface is convex faciolingually. It in indicated in molar replacement, provides access to undersurface for good hygiene, alongwith poor esthetics. 

Image of Modified sanitary pontic design
Modified sanitary pontic design-note the concavity at the cervical region.

Saddle/Ridge Lap

It looks like crown of the tooth because it replaces all the contour of the missing tooth. It maintains a large concave contact with the underlying ridge and obliterates facial, lingual and proximal embrasures. Esthetic wise it provide best result but due to impossible access to under surface for cleaning, its use is limited for the replacement of maxillary incisors.

Image of saddle or ridge lap pontic designModified Ridge Lap

Modified ridge lap combines esthetics with easy cleaning, and makes contact with ridge tissues in a shape of ‘ T whose vertical arm ends at the crest of the ridge. This design is most commonly used in the area of the mouth that is visible during function, e. g. anterior teeth, premolars and sometimes maxillary molars. 

Image of modified ridge lap pontic design
Modified ridge lap pontic design: note the half concave underneath surface in contact with mucosa.

Conical

Conical pontic design is mostly limited to the replacement of thin knife edged ridges in the non-display zone of the mouth. It has a convex surface with only touching the centre of the residual alveolar ridge. It helps maintain good hygiene with poor esthetics. Conical design in indicated for the replacement of molars.

Image of conical pontic design
Image of conical pontic design- note the egg shaped design in green circle.

Ovate

Ovate pontic design is the most aesthetically suitable appealing design that looks like emerging from the gingiva. When ridge resorption is corrected by ridge augmentation, ovate design appears to be emerging through gingiva just like natural tooth. it is indicated for the replacement of maxillary incisors, canines, and premolars. It has the advantage of best esthetics, negligible amount of food entrapment and easy cleaning. The disadvantage is the requirement of surgical preparation of the receiving site before prosthesis fabrication.

Image of ovate pontic design
Ovate pontic design-note the convex undersurface of pontic embedded in mucosa (green circle).

 

There are MCQs on pontic design in “Free silver Course“, which you may like to attempt.

 

References:

  1. Eur J Dent. 2018 Jul-Sep; 12(3): 375–379. doi: 10.4103/ejd.ejd_232_18
  2. Rosenstiel & Tyllman respectively
  3. Pontics

 

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. 

Harmful Effects of Excessive Radiation

The harmful effects of the excessive dose of the ionizing radiation can be divided into two types. These are as follows:  

  1. Deterministic effects and   
  2. Stochastic effects  

 We shall discuss them one by one in detail. 

Radiography: Radiation Safety

In earlier articles on radiography, you studied the effects of ionizing radiation on biological tissues. These effects can be divided into two types- Deterministic and Stochastic. Therefore, the radiation safety becomes of paramount importance white taking a radiograph.

 

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.

Radiography: Effects of Radiation on Oral Tissues

Dentists often encounter cancer patients, who are to undergo radiotherapy or have received it in the recent past. Besides cancer therapy, these patients need dental treatment for different ailments. Therefore, it becomes paramount important for a dentist to know the effects of large doses of ionizing radiation on oral mucosa.

In this section, we shall talk about the effects of radiation on oral tissues.

Radiography: Radiation Biology

Radiation Biology 

Radiation biology is the study of effects of ionizing radiation on living systems. In this article we shall talk about the harmful effects of ionizing radiation on tissues, how does it occur, and how sensitive different types of cells are?

The effects of radiation on the tissues can be divided into 2 broad categories. The Deterministic and Stochastic effects.

 

Radiography: Radiation Physics

In this article termed as radiation physics, we shall talk about the ways, the x-rays are produced, the events that occur at atomic level during their production and how can one save oneself and others.

Production of X Rays  

Electrons that travel from the filament to the tungsten convert part of their kinetic energy into x-ray photons. This phenomenon occurs by the formation of bremsstrahlung and characteristic radiation.  

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?

Please go to to view this test

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

Radiation Protection of Pregnant Women

Is there a safe level of radiation exposure for a patient during pregnancy?

Dose boundaries do not apply for radiation exposure of patients, since the decision to use radiation is reasonable depending upon the individual patient situation. When it has been decided that a medical procedure is justified, the procedure should be optimized. This means that the conditions should achieve the clinical purpose with the appropriate dose. Dose limits are determined only for the staff and not for patients.

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?

NABH Standards for Dental Healthcare Service Providers: Care of Patients

NABH Accreditation Standards for Dental Healthcare  Service Providers  have been outlined in two parts: (A) patient centered standards & (B) organisation centered standards. Here we shall discussed the second chapter of patient centered standards.

Chapter 2: Care of Patients (COP)

NABH Standards for Dental Healthcare Service Providers: Access Assessment and Continuity of care

NABH Accreditation Standards for Dental Health Care Providers  have been outlined in two parts: (A) & (B). Each part has been divided into 5 chapters.

 

(A) Patient Centered Standards

  1. Access, Assessment and Continuity of Care (AAC)
  2. Care of Patients (COP)
  3. Management of Dental Material and Medication (MOM)
  4. Patient Rights and Education (PRE)
  5. Hospital Infection Control (HIC)

Accreditation Standards for Dental Healthcare Service Providers by NABH

National Accreditation Board for Hospitals and Health Care Providers (NABH) has laid down Accreditation Standards for Dental Healthcare Service Providers (DHSP). The entities that can apply for are dental teaching institutions, dental hospitals and clinics. The NABH dental standards have been laid down keeping the Indian beliefs and working environment in mind. The board has laid down the standards that focus on

All About Inferior Alveolar Nerve Block

The inferior alveolar nerve is also known as inferior dental nerve.  It gives off a motor branch that supplies to mylohyoid muscle and anterior belly of digastric. Then it enters mandibular foramen and travels through the inferior alveolar canal. From inferior dental canal it supplies to mandibular third molar, second molar, first molar, and second premolar.  

From the level of the second premolar, it moves forward as mental nerve and exits through mental foramen.  The mental nerve supplies sensory nerve fibres to the chin and lower lip of that side. Within the mandible after mental foramen, it moves forward as incisive nerve and gives sensory supply to mandibular incisors and mandibular canines of that side. 

Dental Burs

Dental Burs

Diamond burs are generally used for reducing tooth structures to prepare cavities for restorations or place crowns or porcelain veneers. Diamonds may also be used to smooth, refine, and polish composite or porcelain material.

Nine reason you should not go for implant supported prosthesis

Implant supported prostheses that include over-dentures, crowns and bridges are the treatment of choice in modern dentistry. They are very predictable in nature and have a track record of very successful life span serving their purpose. But, there are certain

Five reasons you should take an implant supported prosthesis

People often ask me; can I get a fixed artificial teeth? While most of the time, they can get it, but in few unfortunate one, it remained impossible to provide a fixed partial denture due to their unfavorable oral conditions. In those cases, we suggest them, “you should take an implant supported prosthesis”.

Dental Materials Used In Pulp Protection: Resin Sealants

Resin Sealants

 

Properties

These are light activated unfilled resins. Most are relatively viscous and do not set through loss of solvent. They set either by chemical or light activation.

Maxillary Nerve

Maxillary nerve is the second division of the trigeminal nerve. It divides into several branches. You will read here about those that are related to dentistry below.

Effects of Diabetes Mellitus on Osseointegration and Dental Implants

Effect of Diabetes on Osseointegration and Dental Implants

The tenacious hyperglycaemia in diabetic people, hinder osteoblastic activity and modifies the response of parathyroid hormone that adjusts metabolism of Ca and P, decreases collagen synthesis during callus formation, induces apoptosis in lining cells of bone and increases osteoclastic activity due to untiring inflammatory response. It also stimulates deleterious effect on bone matrix and reduces growth and build-up of extracellular matrix. The subsequent result is reduced bone formation during healing.

Type -1 diabetes (insulin dependent) causes decreased bone formation, as well as reduced bone mineral density and higher bone resorption while Type -2 diabetes (non-insulin dependent) produces normal or greater bone mineral density in some patients. It has been detected that insulin not only diminishes the harmful effect of hyperglycaemia by controlling it but also stimulates osteoblastic activity.

Teeth Whitening

Photograph showing before and and after teeth whitening procedure. 

Tooth whitening is done to correct the discoloration of a tooth. When we talk about discoloration of a tooth, we mean to say that  the color of a tooth has changed from its normal white color to  light yellow,  yellow,  light brown to dark brown  or from light grey to dark grey or  to complete black. The discolouration may be of one tooth or all the teeth may be discoloured. Discoloration of a tooth is caused by several factors. It may be due to deposition of external stains over the surfaces of a tooth or it may be because of the internal position of certain chemicals into the teeth structure at molecular level during the period when teeth were being formed in the mother’s womb.