Dental Sealants or Pit and Fissure sealants named after the location they are placed in, these are materials which are placed into the occlusal pits and fissures of the teeth which are susceptible to Caries. Before we dive into the details about Pit & Fissure Sealants, let us look into what exactly are Pits and Fissures on a Tooth surface and why require a Sealant.
What are Pits and Fissures in Tooth?
A Pit is the depression located at the junction of the grooves or cusp slope usually a pin point depression which is present over the grinding surfaces of the teeth.
A Fissure on the other hand is a deep elongated cleft formed between adjoining cusps of the molars or premolars. These are usually developmental grooves which are seen as fissures.
What is a Pit and Fissure Sealant or Dental Sealant?
A Dental Sealant is a material usually restorative which is placed and bonded into the pits and fissures on the occlusal or chewing surface of the teeth. In some cases the Sealants are also placed in Pits on the Buccal or Lingual surface of the teeth (Buccal Pits in lower molars).
The Sealants are basically placed inside the Pits are fissures to prevent any food accumulation and thus prevent onset of Dental Caries. As the Pits are Fissures are a magnet to food debris which lead to bacterial colonization and thus leads to caries. As these grooves are blocked with a Sealant they prevent debris accumulation and thus decrease the risk of cavity formation.
Occlusal surface of young patients have high caries susceptibility due to presence of pronounced cusps and Grooves, pits and fissures. Fluoride which is said to prevent dental caries is usually ineffective in occlusal surface, it is very effective on smooth surfaces of the tooth like Buccal, Lingual and interdental surfaces.
When bacteria colonize in these Pits and fissures, it is impossible with normal brushing to clean or remove the bacteria and food debris as the bristles do not reach the pits. So it is best to close or block these pits and Fissures with sealants to block the entry of debris.
Classification of Pit and Fissure Sealents:
The Dental sealants are classified into different types based on four factors – Polymerization methods, Resin Systems, Presence of Filler and Color. Let us look at the four Classifications of Dental Sealants:
Based on Polymerization methods:
- First Generation: UV Light
- Second Generation: Self Cure
- Third Generation: Visible light
- Fourth Generation: Fluoride releasing
Based on Resin Systems:
- Urethane acrylate
Based on Presence of Filler:
Based on Color:
Materials used in Pit and Fissure Sealants:
- GIC or Glass Ionomer cement
- Flowable resin composite
A Study comparing the three materials – ncbi.nim.nih.gov
Idea Requirements of Pit & Fissure Sealants:
- High Flow properties – low surface tension, low viscosity and low ir zero angle of contact to help flow into the pits and fissures.
- Good and prolonged adhesion to Enamel
- Good working time
- Low sorption and solubility to orla fluids
- Cariostatic property
- Color similar to Enamel
- No irritation to tissues
Indications of Dental Sealants:
- Carious Pit and Fissures on Occlusal surface of tooth, if there are narrow pits and fissures
- Carious occlusal anatomy with a transverse ridge seperating the pit or fissure.
- Newly erupted tooth
- Recently starting carious lesions on the occlusal surface of tooth
Contraidications of Dental Sealants:
- High caries activity in oral cavity
- Presence of high number of proximal lesions
- Rampant caries
- Deep Occlusal Caries
- Teeth without caries for 4 years or longer
Step to Apply Pit and Fissure Sealants:
Cleaning and Isolation of Tooth: Clear any food debris which might be stuck in the fissures, next use a prohpy cup and pumice with water or any tooth paste to clean the occlusal surface of the tooth. Now remove the pumice from the fissures using an explorer. Clean the surface with water spray and dry using air syringe. In case the grooves are narrow, you need to mechanically prepare the fissures to be able to accomidate the sealant. Use of Rubberdam or cotton rolls is sufficient to isolate the tooth from saliva.
Enamel Etching: This is an important step to acheive microporositires within the enamel. Apply 37% phosphoric acid in gel or liquid form to the pits and fissures applied 2/3rd upto the cuspal incline for 20 seconds. Now wash the tooth surface and dry it.
Application of Sealant: Apply the Sealant material based on the material used. Use a probe or a painting brush to guide the sealant material into the fissures. In case of sel curing sealants like GIC you need to keep the arear isolated to prevent any contamination with saliva and avoid air bubbles.
Curing Sealant: In case you are using a light-activated Sealant you need to cure the material using Visible light.
Re-evaluation of Sealant: This is an important step to inspect the sealant placement, in some cases there might be pockets or pits left over even after placement of sealant. Make sure that all pits nad fissures are covered. Do not let the sealant extend over the marginal ridge of the tooth. Check for hihg points to prevent occlusal interference using an articulating paper.