How to do Bonded Sealant and Uncomplicated Crown Fracture

Question 1

This is the simplest type of restorative procedure, and one which can be
attempted in general practice.

Question 2

How to place a bonded
sealant over a fresh uncomplicated crown fracture?

Answer 2

1. Examination under general anaesthesia to identify all lesions and other
   disease processes. Ensure there is no direct pulp involvement.
2. Radiography of the affected tooth to ensure no endodontic pathology.
3. Scale the teeth. Polish with an oil- and fluoride-free prophylaxis paste.
   Flour of pumice is ideal.
4. Using white stone or fine diamond bur on a highspeed handpiece with plenty of water-cooling, the
   sharp edges of enamel are smoothed.
5. Rinse and dry the tooth.
6. Acid-etching. It was shown over 60 years ago that the use of
   phosphoric acid on the tooth surface enhances the bonding of acrylic
   materials to the tooth. The use of 37% phosphoric acid on the tooth
   surface will dissolve away some mineral content, producing a jagged,
   rough surface. In addition, the acid removes the so-called ‘smear layer’
   produced by instrumenting the tooth surface. Think of this as plugs within
   the dentinal tubules, that the bonding agent will not be able to enter.
   a. The acid is carefully placed onto the dental hard tissues for 20
   (dentine)-30 seconds (enamel) before being rinsed off. Be sure
   that no acid remains in contact with oral soft tissues.
   b. Briefly air-dry the area, but do not desiccate it.
   c. The surface of etched enamel will appear ‘frosted’ or chalky
   d. This area must not now be touched or contaminated by water,
   saliva or blood. Ensure you retract the lips and tongue.
7. Bonding agents Many generations of bonding agents have been
   produced over the last 60 years, with each ‘generation’ reporting
   superiority to the last generation. A bonding agent
   must bond to the tooth itself, and then to the
   composite restorative material.
   a. Follow the manufacturers’ instructions closely.
   Apply the bonding agent in a thin layer using
   an applicator brush for 20s
   b. Lightly air-dry the area for 5s
   c. Light cure for 10s (or follow manufacturer instructions)
8. Light-curing The LED curing light is used to cure
   (polymerise) both the bonding agent and composite
   material. A blue light is emitted in the wavelength
   450nm.
   Do not look directly at the blue light as it can
   damage the retina.
   The operator can use the orange shield to view the
   tooth (which will block the blue light) but the assistant
   must be sure not to look at the light.
9. Unfilled resin or Composite placement Dental
   composites are known as ‘white fillings’ and have
   largely replaced the use of amalgam in human
   dentistry. They are composed of a resin matrix plus
   fillers, initiators and accelerators and pigments. A
   resin matrix without fillers is termed an unfilled resin (e.g. Permaseal).
   Pigments define the colour so that exact matches to a patient’s existing
   teeth can be achieved. Composites are generally classed according to
   the size of the fillers. E.g. Midifill, microfill, nanofill. The smaller the size,
   the higher the strength and increased polishability. Composites can also
   be classified according to whether they flow or not. A flowable composite
   is applied via a syringe and will flow slightly to adapt to surfaces. A
   packable composite is solid, and manipulated using restorative.
   instruments such as the ‘flat-plastic’. Apply a flowable composite in a thin
   film over the bonding agent and then light-cure (follow manufacturers’
   instructions). The composite bonds to the bonding agent via the
   polymerisation process, which itself is bonded to the tooth structure. A
   hybrid layer is therefore formed.
   10.Re-check radiograph in 6 months.