Intro and Fissure Sealants Flashcards
What is paediatric dentistry?
An aged defined specialty that provides parimary and comprehensive preventative and therapeutic oral health care for infants and children through adolescence including those with special health care needs.
What is the role of the primary teeth?
Maintains function in infants: Prevents nutritional problems, Mastication, Alveolar bone/facial height/space/arch length, and Speech
Maintains aesthetics
Others: Guide the eruption of permanent teeth
When is the formation of primary dentition completed?
At birth but it is present in the jaw at this stage.
When do primary teeth begin to calcify?
All begin in the 4th foetal month.
When is the formation of primary dentition complete?
Central incisors and lateral incisors At 18 - 24 months
Canines at 30 - 39 months
First molars at 24 - 30 months
Second molars at 36 months
When do primary central maxillary incisors erupt?
6 - 10 months
When do primary mandibular central incisors erupt?
5 - 8 months
When do primary maxillary lateral incisors erupt?
8 - 12 months
When do primary mandibular lateral incisors erupt?
7 - 10 months
When do primary maxillary and mandibular canines erupt?
16 - 20 months
When do primary maxillary and mandibular 1st molars erupt?
11 - 18 months
When do primary maxillary and mandibular 2nd molars erupt?
20 - 30 months
When do the permenent teeth calcify?
CI: 3 - 4 months LI: mand = 3 - 4 months. Max = 10 - 12 months C: 4 - 5 months 1st Prem: 18 - 24 months 2nd Prem: 24 - 30 months 1st M: Birth 2nd M: 30 - 36 months 3rd M: Maxilla = 7 - 9 Mand = 8 - 10 years
What are the differences between the crowns of primary and permanent teeth?
Crown: Primary teeth are whiter than permanent teeth
Thickness: Enamel is thinner in primary teeth than permanent teeth
Overall shape: Crowns of primary molars are bulbous due to their constricted necks and pronouced cervical ridges on the buccal aspect especially in the maxillary and mandibular first molars.
How is the overall size of primary teeth different to permanent teeth?
Primary teeth are smaller than permanent teeth.
Crowns of Primary teeth are wider mesiodistally than incisocerivally.
How are anterior teeth of primary dentition different to the permanent dentition?
No mamelons in primary incisors
Prominence of cingulum and marginal ridges is more on permanent teeth than primary teeth
Incisal angles on the lateral incisor of primary teeth are more rounded than on central incisor
How are the roots different between primary and permanent dentition?
The roots of primary teeth are:
Shorter, weaker, and narrower mesiodistally.
Relatively longer in proportion to its crown length
Wider than the crown to allow room for the development of successor tooth germ.
How does exfoliation occur?
Physiological resorption of the roots of primary teeth occur
How is the pulp chamber different in primary teeth compared to permanent teeth?
Pulp chambers and pulp horns are relatively larger compared with the permanent teeth.
Root canals of primary teeth are more ribbon-like while the roots of permanent teeth are more well-defined.
Where are primate spaces located?
Maxillary arch: Mesial to primary canine
Mandibular arch: Distal to primary canine
What are the types of molar relationships between primary teeth?
Flush terminal - teeth occlude on the same level
Mesial step - Mandible protruding more forward
Distal step - mandible protruding more posteriorly
What possible occlusions can distal step lead to in permanent dentition?
Class 2 and end to end occlusion
What possible occlusions can flush terminal plane lead to in permanent dentition?
End - to - end
Class 1
What possible occlusions can mesial step lead to in permanent dentition?
Class 1 occlusion
Class 3 occlusion
What are leeway spaces?
Combined mesiodistal width of permanent canines, and premolars is usually less than that of primary canines and molars.
How much is the leeway space in the maxillary arch?
0.9mm / quadrant for a total of 1.8mm
How much is the leeway space in the mandibular arch?
1.7mm / quadrant for a total of 3.4mm
What is the function of the leeway space?
The excess space is utilized for mesial drift of mandibular molars to establish a class 1 molar relationship
What is a pit?
A small pin point depression located at the junction of developmental grooves or at terminals of those grooves.
What is a fissure?
A narrow channel, groove, cleft, ditch, or crevice which may sometimes be deep
It is formed at the depth of developmental grooves during the development of the tooth
Could also be a deep cleft between adjoining cusps
Why should pit and fissure sealants be used?
Tooth surfaces with pits and fissures are particularly vulnerable to caries development.
Toothbrush bristles are sometimes too big to enter and clean pits and fissures
What are the types of pits and fissures?
V-type (34%) Are wider at the top and narrower at the bottom. They are shallow and self cleansable and somewhat caries resistant.
U-type (14%) are almost the same width from top to bottom, shallow, self cleansable, and somewhat caries resistant
I-type (19%) Are extremely narrow slit openings which may resemble bottle necks. Depth of fissure may be close proximity to the DEJ. They are plaque retentive and mechanical plaque removal is very difficult.
IK- type (26%) Are extremely narrow slits with associated large spaces at the bottom as they extend towards the DEJ. They may have a number of different branches and are more susceptible to caries.
Inverted Y (7%) Narrow slit like opening large base as it extends towards the DEJ and may have a number of different branches.
What is a fissure sealant?
A material placed in the pits and fissures of teeth in order to prevent or arrest the development of dental caries.
Why are pit and fissure sealants used?
They are non-invasive
They can prevent dental caries initiation and can arrest caries progression
How do sealants work?
They provide a barrier between the sealed area of the tooth and microorganisms of the mouth.
Sealants make it easier to clean the area via tooth brushing or mastication.
Keep substrates out of pits, fissures, and grooves.
What determines the effectiveness of sealants?
Effectiveness of sealants is dependent on their long term retention.
How effective have sealants been in preventing occlusal caries incidence?
Sealants have been shown to be highly effective in reducing occlusal caries incidence in first permanent molars.
76.3% at 4 years
65% at 9 years from initial treatment
No reapplication in the last 5 years.
What are the properties of an ideal sealant material?
Non-toxic and non irritating
Biocompatibility with oral tissues
Free-flowing low viscosity
What are the indications for fissure sealants?
High risk caries patients
Deep, narrow fissure patterns
Deep, inaccessible pits of permanent molars
Deep palatal and buccal pits
Invaginations on anterior teeth
Patients with special health care needs
Patients with limited manual dexterity
What are the classes of sealants?
GICs: Conventional and resin modified
Resin-based materials: Autopolymerised, photopolymerised, and a combination of the 2 processes.
Which class of sealant is more effective?
Studies show that GIC has significantly lower retention rates than resin based sealants.
Studies show that GIC has a cariostatic effect even after macroscopically disappearing.
Limited evidence that GIC reduces caries incidence in permanent teeth
Resin based sealants adhere to underlying enamel via etch-bond technique. Their caries preventive property is based on light seal formation which prevents nutrient entry towards the caries.
CONCLUSION: Inferiority claims against HVGIC in comparison to resin-based sealants as current gold standard are not supported by evidence.
How can need examination be done of caries?
Visual examination: ICDAS
Tactile examination: Contraindicated
Radiographic examination: Occlusal carious lesions rarely visible radiographically until there is significant dentine demin.
How is fissure sealing done?
Isolation
Surface cleaning (prophylaxis)
Etching
Washing and drying
Application
Recall and maintenance for sealants.
What causes sealant loss?
Inadequate moisture control is the primary reason for sealant loss.
Resin-based sealants are hydrophobic and require isolation that assures no salivary contamination.
How is isolation from moisture achieved during fissure sealing?
Isolation may be accomplished using:
Rubber dam (MOST EFFECTIVE METHOD)
Cotton rolls (Also highly effective)
Dry angles/dri-aides
Parkell dry-field mouth prop
The isolite or isodry
Blue boa
How is isolation with a cotton roll achieved?
Using Garner’s clamps.
What problems can arise from poor isolation?
If the enamel porosity created by etching procedure is filled by liquid the formation of resin tags in the enamel is reduced and the resin is poorly retained.
Salivary contamination during and after acid etching can lead to preceipitation of glycoproteins onto the enamel surface greatly decreasing bond strength to the PS.
If this occurs, re-etching is needed.
What does pumice do and is it recommended?
The effect of acid etching alone seems to be optimal for surface cleaning.
Pumice removes enamel pellicle and organic debris to enhance bonding. However, it is retained in the pit and fissure system even after a 60 second wash meaning it can influence resin penetration.
CONCLUSION: Pumice prophylaxis is unnecessary and possibly counterproductive.
What is the goal of acid etching?
The goal of etching is to produce uncontaminated, dry frosted surface.
Etching kills 75% of bacteria in the fissures.
Does etching timing make a difference?
After 15 seconds there is no difference in retention of fissure sealants after 1 year.
What should be done to etch after application for correct time?
It should be washed for about 30 seconds then dried for 15 seconds with compressed air.
What is the effect of bonding agent?
Reduces the saliva’s effect on sealant microleakage.
Useful where moisture control is difficult to achieve especially for buccal and lingual surfaces.
What affects bond strenght and causes failure?
Moisture
Organic debris
Blood
Salivary pellicle
Oil from air compressors / handpiece
How should fissure sealants be followed up?
All sealed surfaces should be regularly monitored both clinically and radiographically
Radiographs should be taken at a frequency consistent with patient’s risk status
How often do sealants fail?
Even when applied properly 5 - 10% of sealants can fail annually.
How often should sealants be applied?
Whenever old sealant is defective or lost.
Expectation of every sealant is that it will be reapplied a bunch of times.
Conclusions:
Application of sealants recommended to prevent and control caries
Sealing occlusal surfaces of permanent molars in children and adolescents reduces caries up to 48 months.compared to no sealant. After longer follow up the quantity and quality of evidence is reduced.
Is there a BPA risk from resin based fissure sealants?
Evidence suggests that patients are at no risk for exposure to BPA.
What is PRR?
Preventative resin restoration utilizes adhesives restorative material in conjunction with sealants
Caries is removed a restoration is placed and adjacent pits and fissures are sealed at the same time
