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.

Indications and Contraindications of a Dental Crown

Crown and bridges are being served to dental patients routinely as its manufacturing has become fast, readily available. It is a dependable option. 

Although, the crown & bridge is generally considered very safe and it is associated with a low incidence of complications, there are some precautions that need to be considered.

Indications of a Dental Crown

1. Cases where the tooth has been damaged beyond repair: If the patient has a large cavity that cannot be fixed with a filling, but the dentist determines that the dentine and pulp are in good condition then he will recommend that a crown be placed to save the tooth.

2. When large fillings need replacing: Fillings need replacing every so often, your dentist may recommend installing a crown instead of re-filling the tooth, the reasons for this are the crown is a long term solution and it is esthetically more pleasing.

3. Fractured tooth: In the case that a tooth gets fractured due to a dental trauma or progressive tooth decay, it is highly recommended that a procedure known as post and core be performed. The post and core procedure simply put, is the placement of an implant without extracting the root. In this procedure a small rod is inserted into the root of the affected tooth, this rod will slightly protrude and the core or crown will be attached to it. For this procedure, the tooth in question will require a root canal before the post and core can be done.

4. Enhanced esthetics: For patients who have discolored or uneven teeth, or even for those who have large fillings the use of crowns can greatly improve the esthetics of their smile.

5. To cover dental implants: When a patient has lost a tooth for any reason, and an implant is required to maintain proper function, the implant will be covered by a porcelain crown that has been made to match your existing teeth.

6. To affix dental bridges or dentures: A dental bridge is a prosthetic used to replace missing teeth, these bridges are permanently adjoined to either dental implants or crowned teeth. The dental crowns are used to hold the prosthetic in place.

7. Dental erosion: The tooth enamel can be dissolved by the acidity in foods; when the enamel has been compromised, porcelain crowns are the ideal solution to prevent the progression of tooth decay to the dentine and pulp. Other forms of erosion include tooth abrasion which occurs from improper uses of toothbrushes, brushing too hard, improper flossing or biting on hard foods. And it also includes conditions where natural tooth to tooth friction happens, as in the case of involuntary grinding known as bruxism.

Contraindications

As with any medical procedure, it is possible that complications can arise. Among the risk factors and contraindications of dental crown procedures, we can list the following:

1. Illnesses where the use of anesthesia is contraindicated: These may include severe heart disease, recent strokes and allergic reactions to anesthesia.

2. The use of crowns is not indicated in cases where the problem can be solved with a filling.

3. There is a risk that during the preparation phase, the tooth’s surface can become too thin or be perforated by an instrument.

4. During the preparation procedure, nerve damage can occur, if this should happen, it will be necessary to perform a root canal.

5. Bite misalignment, although in most cases dental crowns can correct TMJ (temporomandibular joint), if the crown is incorrectly placed, it can exacerbate the problem in some patients. Once the dental crown is in place, your dentist should check the fit taking into account the surrounding teeth as well as the whole bite.

6. Allergic reactions to one or more of the materials. Dental crowns can be made from a variety of materials, choosing the right material will minimize the chances of an allergic reaction.

7. Infections, if the dental crown is not properly sealed or if the damaged tissue was not properly removed, the area might become infected.

 

 

Tooth 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.

Composites: Properties

You have read about the composition of dental composites in earlier class notes This article will speak about the properties. 

Properties of Composites

The important properties of the composites are as follows:

1. Polymerisation shrinkage - should be low
2. Water sorption - should be low
3. Coefficient of thermal expansion - should be same as tooth
4. Fracture resistance - should be high
5. Wear resistance - should be high
6. Radiopacity- should be high
7. Bond strength to enamel & dentin - should be high
8. Colour match to tooth structure - should be excellent
9. Manipulation - should be easy
10. Finishing and polishing - should be easy

Few of the above mentioned properties may be important for anterior than posteriors restorations and vice versa. The properties of microfilled and nanofilled composites are same while the microhybrid's differ from both of them.

Composites: Composition

Composites are tooth coloured restorative materials that are usually recommended for class III, IV and class I cavities with less or no occlusal stress and esthetics are important. Specially designed composites are used in almost 50% of class II restorations, although less durable in comparison to dental amalgam. Composites can be classified as microfilled, nanofilled, flowable, packable, all purpose and laboratory. Composites are used for provisional restorations and core build-ups and in fibre-reinforced posts.

Direct Esthetic Restorative Materials

There are four types of direct esthetic restorative materials currently in use. They are:

1. Composites
2. Compomers
3. Hybrid Ionomers
4. Glass Ionomers

Composites are dominating the materials used for direct esthetic restorations. Glass ionomers are primarily used for restorations of cervical eroded areas. Hybrid ionomers provide better esthetics than glass ionomers. Compomers provide improved handling and fluoride release when compared with composites.

Journey of a Dentist for ADC Exam

Introduction

This story of a dentist tells about the journey of a dentist for ADC exam and the mental, physical and economic sufferings full family went through after his failure.

Ganesh was a general dental practitioner with a nice practice in a class two city. Isha was a tutor in a Dental college in the same city. The couple had been living a happily married life with their 5 years old son and their parents in a joint family.

Journey of Dentist to Australia: Part 2

Saudi Arabia Riyadh landscape at Morning – Riyadh Tower Kingdom Centre, Kingdom Tower, Riyadh Skyline – Burj Al-Mamlaka, AlMamlakah – Riyadh at Daylight – Tower View-Getty Images

Click to read part 1 of the story at the link given below

Journey of Dentist to Australia: Part 1

....... Continues

With the passage of time,  Ganesh became aware of the situation of his family. He started to understand the pain of his wife and the thought process of his father. He, who always cared for him, was worried about his future; the future ahead of his family life as well as financials, as it has to have a long lasting effect on his Son too.

Both Ganesh and his wife dropped the idea of ADC as it was clear, no matter how hard they try it, it was not meant for them. Moreover, they were out of funds, rather, better word was, in negative funds. So, to regain their lost finances, they modified their plan. 

The plan was to try for a gulf job and regain the lost finance. They consulted with their friend who had the experience of the gulf job. Ganesh and his wife got a decent job in Saudi Arabia. It was a job in a remote area of the Kingdom, but since they had their own circumstance, they adjusted themselves in a few months.

In this world there is no end of issues, no matter where a person lives. This soon started being applied to them too. A recently came new dentist in their workplace had Arab origin and the staff started giving him preferential treatment. The distribution of work started skewing, putting Ganesh in a difficult situation. His wife was cool as being a female, she was spared or the person involved had no guts to disturb her and be caught in a situation that might have backfired.

Ganesh contacted his friend for solace. He understood his situation and the options available. He decided, as long as I am getting my salary, I have to stay here and refill my coffer. There was no second choice.

His wife and he stayed for five years in Saudi Arabia and then started thinking of  coming back to India. They have earned sufficient, filled their coffer and most importantly regained the lost self esteem and self worth. Their family life has again come back on the smooth track.

Before coming back to India, Ganesh refurbished his old clinic when he had visited India last time. It was ready to start the work. Ganesh started working  in his own clinical practice the next day of arrival to India. His wife got her old tutoring job back in the same college she was teaching in. Within a year, they decided to open a second clinic. Soon it was booming by the hard working ethics of his wife, who decided to go take the clinical practice as full time work.

The couple decided to buy a house near their old home and were happy ever after. Ganesh remained obliged to his friends who supported him during his bad time. 

Polysulfide Impression Materials

Permlastic is a polysulfide, condensation-cured, elastomeric impression material in three viscosities

Polysulfide impression materials are flexible but do not have the major changes in dimensions during storage like agar and alginate. Furthermore, the polysulfide impression is much stronger and more resistant to tearing than agar or alginate. It can be electroformed and therefore metal dies or models, in addition to gypsum models, can be prepared. 

Design of a Custom Tray for Final Impression for Complete Denture

The custom trays also known as special trays are fabricated so that the final impression of the patient’s edentulous mouth can be taken accurately with proper border extension. The selective pressure technique helps in making the impression in such a way that when the newly fabricated dentures are worn by a patient, they exert pressure only on those areas of the mouth that can withstand the masticatory load. The selective pressure technique of impression making spares the non-pressure bearing area of the edentulous jaw and thus eliminate the possibility of trauma resulting in pain and ulceration in the mucosa. The special tray for selective pressure technique is made on the primary cast that has been prepared by pouring the impression made in alginate or impression compound. The impression taken in impression compound records the mucosa in a compressed state whereas the impression taken with alginate records the mucosa in a non-compressed state. From these two opposite states of mucosa record, a dentist proceeds to prepare a special tray that is used to make an impression with selective pressure. We will learn here as to how to make a special tray on a cast that has been made from impression compound.