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.

Tooth Whitening

Tooth Whitening

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 discoloration may be of one tooth or all the teeth may be discolored. 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.

Crown and Bridges

A crown is provided to protect the weakened natural tooth, regain its shape, maintain or enhance the esthetics and regain the functional ability of a person. A bridge is a prosthesis that is constructed to replace the one or more missing teeth and is supported by the neighbouring teeth.

Tooth showing a tooth preparation for full crown
A posterior tooth prepared for full crown (pink area)
B-Buccal aspect, L-Lingual aspect

They can be constructed in variety of the materials as follows:

  1. All Metal
  2. Porcelain fused to metal
  3. All ceramic material
  4. Pressed ceramic
  5. All acrylic

There are various types of crown based on the surfaces they cover.

  1. Full coverage crown
  2. 3/4 crown
  3. 4/5 crown
  4. Inlay
  5. Onlay

All metal includes precious metals like gold alloys, semi-precious that contains lesser amount of gold and non-precious alloys that are basically chrome- cobalt or nickel- chrome alloys.

Porcelain fused to metal crowns and bridges are made in any one of the above mentioned alloys. This metal crown, in the later phase of construction, is sintered with ceramic powders and chemo-mechanically fuses with metals in ceramic furnace.

“All ceramic” crown is made in Ceramic only. Aesthetically they are the best. Their con is that they are not as strong as metal ceramic or pressed ceramic.


A variety of factors have to be considered for the construction of a bridge.

  1. Span of the edentulous area
  2. Type of the teeth being replaced
  3. Quality of supporting teeth
  4. Conditions of the teeth in the opposing arch
  5. Age of the patient
  6. Patients’ ability to bear the treatment cost

Span of the edentulous area means how many teeth have to be replaced by bridge. The more number of teeth to be replaced, the longer will be the bridge; that in turn, will cause more stress in the bridge itself as well as onto the supporting teeth known as abutments. More stressed bridge will get more fractured ceramic from the metal part.

Type of the teeth decides as to how much masticatory load will have to be borne by the abutments. In case of the lateral incisor pontic, supported by one central incision and one canine, the masticatory load over abutments will be minimum. As we move from the Canines through Premolars to Molars, the quantity of masticatory load increases. Accordingly, we need to increase the number of abutments.

Quality of supporting teeth means how healthy the attachment apparatus of the supporting teeth is present. The healthier the apparatus, the better will be the masticatory load bearing ability of the abutments. It will result in a relatively longer life span of the bridge with minimum number of abutments. If the available healthy root surface area of the abutments will be less than the root surface area of the tooth or teeth being replaced, then more number of teeth should be used as abutment to prevent the overloading of any particular abutment tooth and ultimately bridge failure.

Conditions of the teeth present in the opposite dental arch includes the considerations of occlusal surface of the tooth and whether it is extruded. Is it causing mandible deviation during chewing?

Age wise a very young patient cannot be given crown and bridge as their pulp chambers are usually large and the trauma caused by heat during crown preparation or acids of luring agents may render the pulp tissue death. This may lead to pulpal or periapical pathology leading ultimately to the failure of the bridge.

Treatment cost of the PFM bridges are very high. Therefore, the patient must understand the importance of the maintenance of the oral hygiene for the longer life of the prosthesis. The patient should be able to bear the cost of this treatment, otherwise a less expensive treatment needing easy maintenance should be chosen.

Further Readings