Pit and Fissure Sealants
Pit and Fissure
Pit
· A small pin point depression located at the junction of developmental grooves or at terminals of those grooves
Fissure
· It is a narrow channel, groove, cleft, ditch or crevice which may be sometimes deep · It is formed at the depth of developmental grooves during the development of the tooth · (or) deep clefts between adjoining cusps
Caries Vulnerability
· Tooth surfaces with pits and fissures are particularly vulnerable to caries development (Manton and Messer, 1995)
· Although the occlusal surfaces represented only 12.5% of the total surfaces of the permanent dentition, they accounted for almost 50% of the caries in school children (Ripa, 1973)
· The plaque accumulation and caries susceptibility are greatest during the eruption of the molars (Carvalho et al. 1989)
· This vulnerability is due to:
o Complex Morphology: The deep, narrow anatomy of pits and fissures makes them impossible to clean effectively with a toothbrush, as a single bristle is too wide to reach the base.
o Plaque Accumulation: Bacteria, food, and debris become trapped, creating an ideal environment for caries to initiate and progress.
o High-Risk Periods: This is a particular issue during childhood and adolescence when oral hygiene and dietary habits may be suboptimal.
Pit and Fissure Sealant
· Toothbrush bristles are sometimes too big to enter and clean pits & fissures · Approximately 90% of carious lesions found in the pits and fissures of permanent posterior teeth
The form of Pit and Fissure
Pits and fissures can be classified into the following forms: A histological study by Nagano revealed that the clinical appearance of a fissure does not reflect its complex internal morphology. The key takeaway is that a fissure system is far more intricate than what is visible to the naked eye, and these complex patterns are at a higher risk for caries.
V-type (34%)
· wider at top & narrow at bottom · shallow · self cleansable · somewhat caries resistant · non-invasive techniques Nagano 1961
U-type (14%)
· almost the same width from top to bottom · shallow · self cleansable · somewhat caries resistant · non-invasive techniques Nagano 1961
I-type (19%)
· an extremely narrow slit opening (quite constricted) · may resemble a bottle neck · depth of fissure may be close proximity to the DEJ · plaque retentive · mechanical plaque removal is difficult · caries susceptible Nagano 1961
IK-type (26%)
· extremely narrow slit · associated with a large space at the bottom as it extend towards DEJ · may have a number of different branches · caries susceptible Nagano 1961
Inverted Y (7%)
· narrow slit like opening · large base as it extend towards DEJ · may have a number of different branches · caries susceptible Nagano 1961
Pit and Fissure Sealant
Definition
A fissure sealant is a material that is placed in the pits and fissures of teeth in order to prevent or arrest the development of dental caries (Weibury et al. 2004)
Purpose
· Sealants are non-invasive
· Sealants can be placed for two main reasons:
○ to PREVENT dental caries initiation
○ to ARREST caries progression i.e. used as preventive and therapeutic treatment
· The definition highlights two distinct clinical applications:
a. Prevention: Applying a sealant to a sound, caries-free tooth to prevent a lesion from ever starting. This is a primary preventive measure to avoid the 'restorative death spiral.'
b. Arresting Caries: Applying a sealant over an existing non-cavitated carious lesion (e.g., ICDAS 1-4) to cut off its nutritional supply and halt its progression.
How do Sealants work?
· Sealant provide a physical barrier between the sealed area of the tooth and the microorganisms in the mouth · Sealants make it easier to clean area via tooth brushing or mastication · Keep substrates out of pits, fissures and grooves · ➤ Effectiveness of sealants is dependent upon their long term retention
History
· 1895 Wilson o Used zinc phosphate cement · 1905 Miller o Application of silver nitrate · 1923 Hyatt o Prophylactic odontotomy · 1929 Bodecker o Fissure eradication · 1942 Kline & Knutson o Ammonium silver nitrate · 1955 Buonocore o Advocated bonded resins-acid etching (concentrated phosphoric acid) · 1962 Bowen o Introduced BIS-GMA material
1895 - Wilson’s Preventive Dentistry
Instead of attempting excavation in such cases, let the fissures be thoroughly cleaned, washed with an astringent fluid to dehydrate with alcohol, dry thoroughly, and fill with cement. Then place a little of the dry powder over the filling and press it firmly with the finger, forcing the cement into the remotest recesses of the fissures, - Wilson IP.
1923 - Hyatt’s Prophylactic Odontotomy
Prophylactic Odontotomy: The Cutting into the Tooth for the Prevention of Disease.
1929 - Bodecker’s Fissure Eradication
Bodecker, C. F. (1929). “Th · Note: *Prophylactic odontotomy and fissure eradication are outdated, invasive historical concepts that are no longer practiced in modern evidence-based dentistry.*e eradication of enamel fissures.” Dent Items Int 51: 859.
1942 - Kline & Knutson’s Study
Kline H, Knutson JW. Studies on dental caries XIII. Effect of ammoniacal silver nitrate on caries in the first permanent molar.*
1955 - Buonocore’s Adhesion Method
Buonocore MG. A simple method of increasing the adhesion of acrylic filling materials to enamel surfaces. J Dent Res. 1955;34:849-853.
Reduction in Occlusal Caries Incidence
· Sealants have been shown effective in reducing occlusal caries incidence in first permanent molars o 76.3% at four years o 65% at nine years from initial treatment o no reapplication in the last five years
Properties of an Ideal Sealant Material
· Non-toxic and non irritating
· Biocompatibility with oral tissues
· Free-flowing low viscosity material
· Capable of entering narrow fissures
· Low solubility in the oral environment
· Sustained bonding to enamel
· Cariostatic action
· Simple application by dentist / hygienist
· Should be less technique-sensitive, which is especially important when treating children.
Indications
· High caries risk patients
· Patients identified as having high or extreme caries risk based on biological indicators, diet, and fluoride history (e.g., Featherstone's CAMBRA model).
· Deep, narrow fissure patterns
· Deep, inaccessible pits of permanent molars
· Deep palatal and buccal pits
· Invaginations on anterior teeth
· All Susceptible Teeth: Sealants are not limited to molars. They can be used on premolars, primary teeth, and anterior teeth with susceptible anatomy (e.g., cingulum pits, talon cusps, dens evaginatus).
· Patients with special health care needs
· Patients with limited manual dexterity
Types of Sealants
Based on Material
· Resin based materials o Autopolymerised o Photopolymerised o Combination of two process · Glass ionomer cements o Conventional o Resin modified ○ Resin modified GIC is not really used because it has the worst outcomes of both
Glass Ionomers Sealants
Conventional GICs are used, not resin-modified GICs, as the latter are more moisture-sensitive.
Advantages
· Generally easier to place
· Not as moisture sensitive
· Bond to the tooth structure
· Fluoride release
· but this effect should not be overstated; it is not a 'magic cure' for caries and is a minor benefit.
Indications
· When moisture control is difficult to achieve o GIC can be used as an interim preventive measure until resin based sealant can be placed e.g. until adequate moisture control is achievable · Partially erupted teeth · Developmental defects of enamel o hypomineralised / hypoplastic teeth
Specific GIC Materials
· Fuji 7: A purpose-designed sealant material with very low viscosity and high flow, making it ideal for penetrating fissures. · Fuji 9 / Equia Forte: High-viscosity GICs designed for restorations. While they can be used as sealants, they are more viscous and harder to adapt into deep fissures. · The tip of a fuji 7 capsule is different to a Fuji 9 capsule
Retention and Efficacy
· Studies on the use of GCAs fissure sealant indicate significantly lower retention rates than resin-based ones · Some studies showed that GICs exert a cariostatic effect even after they disappeared macroscopically o this effect might be based on remnants of the cement in the fissure as well as increased levels of F on the enamel surface · Limited and conflicting evidence that GIC reduces caries incidence in permanent teeth
Resin based Fissure Sealants
· Resin based fissure sealants are bonded to the underlying enamel by the use of the acid etch technique · Their caries preventive property is based on the establishment of a tight seal, which prevents leakage of nutrients to the microflora in the deeper parts of the fissure · The resin sealants may be either pure resin composites or compomers, and their polymerisation may be initiated chemically or by light
Advantages
· Superior Retention: The micromechanical bond created by acid-etching enamel is extremely strong and durable, leading to better longevity.
Specific Resin Materials
· Conceal F: An unfilled resin sealant. It is very low viscosity and highly flowable. · Filtek Supreme Flow: A filled, flowable resin composite . It is more viscous than unfilled resins but has better wear characteristics and higher compressive strength.
GIC vs. Resin Efficacy
· A systematic review by Mickenautsch & Yengopal found no statistically significant difference between high-viscosity GIC and resin-based sealants in terms of their ability to prevent caries. · While resins last longer (better retention), this does not translate to superior clinical effectiveness in caries prevention.
Examination
· Visual examination
○ ICDAS visual assessment protocol
○ This is the gold standard. Vague terms like 'occlusal watch' should be avoided.
· Tactile examination
○ a sharp dental explorer used for detection/diagnosis of occlusal caries is contraindicated
§ It provides no diagnostic benefit and can cause iatrogenic damage to enamel. A blunt-ended probe may be used cautiously.
· Radiographic examination
○ occlusal carious lesions rarely visible radiographically until there is significant dentine demineralization
○ A lesion is often not visible until it has reached the dentino-enamel junction (DEJ) or the outer third of dentin.
Technique For Sealing
· Isolation · Surface cleaning (Prophylaxis) · Etching · Washing and drying · Application o Evaluation o Adjustment · Recall and maintenance for sealants
Time to seal
· There is good evidence that teeth sealed very early after eruption require more frequent reapplication of the fissure sealant than teeth sealed later
· Therefore, fissure sealant placement may be delayed until the teeth are fully erupted, unless high caries activity is present
· Placement of fissure sealant even in the absence of regular followup is beneficial
· This requires clinical judgment based on caries risk.
o Wait for Full Eruption: Allows for better access and easier, more effective isolation, leading to a better seal.
o Seal Early: In high-risk patients or on teeth with enamel defects, it may be beneficial to seal a partially erupted tooth to prevent caries from developing during the 1-year eruption period.
Isolation
· Inadequate moisture control is the primary reason for sealant loss · Isolation is the single most critical factor for sealant success. It takes only one second of saliva contamination to compromise the enamel etch pattern. · Resin-based sealants are hydrophobic and require isolation that assures no salivary contamination · Isolation may be accomplished using: o Rubber dam o Cotton rolls o Dry angles/dri-aides o Parkell dry-field mouth prop o The isolite or Isodry o Blue Boa · Cotton rolls (Garmers clamp) · Rubber Dam o when properly placed, provides the best, most controllable isolation o discomfort during clamp placement o need for local anaesthetic?
Cotton rolls Vs rubberdam
· provide comparable retention rates (Lygidakis et al. 1994)
· Rubber Dam: The gold standard for isolation, providing the most predictable and effective moisture control. However, it may require a clamp and local anesthesia, which can be challenging in young children.
· Cotton Rolls: Can be as effective as a rubber dam if used with exceptional skill . However, maintaining a dry field is difficult, as the patient's tongue can easily dislodge the rolls and contaminate the tooth.
Isolation Methods
· Rubber dam
· Cotton rolls
· Dry-guards
· Crucially, they must be wetted thoroughly before removal to prevent stripping the mucosa.
· Garmers Clamps
· Dry-angle
· Parkell dry-field mouth prop
· Isolite
· Blue Boa
Importance of Isolation
· Adequate isolation is the critical aspect of the fissure sealant outcome
· If the enamel porosity created by the 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, allows the precipitation of glycoproteins onto the enamel surface, greatly decreasing bond strength to the FS (Silverstone, 1984; Donnan and Ball, 1988)
· If this occurs, re-etching is needed
· A poor seal resulting from inadequate isolation can fail and may even increase caries risk by creating a niche for plaque accumulation under the leaking margin.
Surface cleaning (Prophylaxis)
· The need for surface cleaning and the method of cleaning pits and fissures prior to fissure sealant placement may seem to be controversial Routine cleaning of the fissure with pumice or prophy paste is unnecessary and contraindicated. · Raadal et al. 2001 suggests careful removal of plaque and pellicle by the use of pumice or air-polishing instruments in order to obtain optimal acid-etch pattern of the enamel · Harris and Garcia-Godoy, 1999 maintains that the effect of acid etching alone is sufficient for surface cleaning provided obvious soft material has been removed
Scanning electron microscope photograph illustrating debris and pellicle on the cuspal slopes of a molar tooth
Use of Pumice for Prophylaxis
· Pumice is used to remove enamel pellicle and organic debris, and to enhance bonding
· Taylor & Gwinnett (1973) showed that pumice still remained within the fissure system when it was used to remove surface organic debris
· Asquinazi et al. 1999 used radioactively labelled pumice and showed that some of the pumice used in the prophylaxis retained within the fissure system even after a 60 sec wash, or the combined action of etching for 30 sec followed by a 30 sec wash
· Gwinnett & Buonocore, 1972 showed that pumice deposits in the pits and fissures would adversely influence resin penetration
· Donnan & Ball, 1988 concluded that pumice prophylaxis unnecessary
· Cleaning with a bristle brush and water is sufficient if needed.
Pumice for Prophylaxis (Burrow et al. 2003)
Montage of molars showing the negative images of the fissure systems. Pink: sealant; blue: prophylaxis material; clear layer: organic material
Etching
· The goal of etching is to produce an uncontaminated, dry, frosted surface (Manton and Messer, 1995)
· Acid etching kills 75% of bacteria in the fissures (Theilade et al. 1977 )
· Use 37% phosphoric acid .
· An etch time of 15-30 seconds is sufficient for enamel; there is no benefit to over-etching.
· Frequently used etchant is orthophosphoric acid (concentration between 30% and 50% by weight)
· Duggal et al. (1997) showed no significant difference in retention of fissure sealants after one year follow-up on second primary and first permanent molars when 15, 30, 45 or 60 seconds etching times were used
Washing and Drying
· Tooth irrigated vigorously with air and water for about 30 sec
· Dried with uncontaminated compressed air for 15 seconds (Manton and Messer, 1995)
· It is good practice to purge the air line away from the patient first.
· Water under pressure in air-water spray with suction
· Suction tip placed above/adjacent the tooth
· Use a suction tip adjacent to the tooth to prevent saliva contamination during this step.
· The exact washing and drying times are not as important as ensuring that both washing and drying are thorough enough to remove all etchant from the surface of the tooth to give a chalky, frosted appearance (Waggoner and Siegal, 1996)
Etched, Washed & Dried Tooth Surface
Etched tooth surface – dried frosted surface The properly etched enamel surface should have a distinct chalky, frosted white appearance .
Bonding Agent
· Feigal et al. 1993; 2000 showed when a single-bottle bonding system was used as a layer between enamel and sealant:
○ decreased risk of failure of occlusal sealants by 47%
○ reduced the risk of failure of buccal/lingual sealants by 65%
· Buccal and lingual surfaces are subject to continuous flexure in the process of mastication. Bonding agent provides a stress-breaking effect and improves sealant bond (Feigal et al. 2000)
· Bonding agent reduces the saliva’s effect on sealant microleakage
· Useful where moisture control is difficult to achieve especially for buccal and lingual surfaces
· The use of a bonding agent depends on the type of resin sealant being used.
o For Unfilled Resins (e.g., Conceal F): A bonding agent is NOT required . The unfilled sealant itself acts as the bonding layer. The steps are: etch, wash, dry, apply sealant.
o For Filled Resins (e.g., Filtek Flow): Using a single-bottle bonding agent (e.g., Adper Single Bond) is beneficial . A study by Feigal showed it decreased sealant failure rates by acting as a stress-breaking layer, improving longevity. The steps are: etch, wash, dry, apply bond, apply sealant.
o Caution: Do not use universal adhesives (e.g., Scotchbond Universal) for this purpose, as they can compromise sealant retention. Always read the manufacturer's instructions for the specific materials being used.
Bond strength failure: potential contaminants
· moisture · organic debris · blood · salivary pellicle · oil from air compressors / handpiece
Etchants & Conditioners
· Etchant (Phosphoric Acid): Used for resin-based sealants to create micromechanical retention tags in enamel. · Dentine Conditioner (Polyacrylic Acid): Used to remove the smear layer before placing GIC in dentine . For sealing enamel , studies show no significant benefit to conditioning the surface before placing a GIC sealant, so it is not recommended .
Application of Fissure Sealant
A flowable composite resin has been used and is spread into the fissures with a ball- burnisher · Resin: Use a fine-tipped syringe to apply the material, starting at one end of the fissure and dragging the tip along to prevent trapping air bubbles. Use a ball burnisher to gently adapt the material into the grooves and along the cuspal inclines. · GIC: Can be applied and adapted using finger pressure . A ‘finger glove’ (a clean glove finger placed over the operator’s gloved finger) should be used to ensure a non-contaminated surface for adaptation. This technique is only for GIC , not resin.
Cured Fissure Sealant
Light cured composite resin
Evaluation – Finishing and Polishing
· Finishing Tools
○ cup
○ disc
○ point
· Grade
o Coarse
o Medium
o Fine
o Super fine
· If the sealant is well-adapted, minimal to no finishing is required.
· Check the occlusion carefully.
· If adjustment is needed, use finishing systems like Enhance cups or points .
· Strong Warning: Avoid using Sof-Lex discs for finishing sealants in children. They are extremely risky and can easily cause severe lacerations to the tongue or cheek if the child moves unexpectedly.
Follow up and Maintenance
· All sealed surfaces should be regularly monitored both clinically and radiographically · Radiographs should be taken at a frequency consistent with the patient’s risk status · Even under proper application conditions, 5-10% of sealants can be expected to fail annually (Yazici et al. 2006) · Defective or lost fissure sealants should be repaired when deficient (if they are to be effective) - provided the surface is caries free · “In practice sealants are not made to be applied once” Ripa, 1985
Sealants for preventing dental decay in the permanent teeth (Review)
Ahovuo-Saloranta A, Forss H, Walsh T, Hiiri A, Nordblad A, Makela M, Worthington HV
Objectives
To compare the effects of different types of fissure sealants in preventing caries in permanent teeth in children and adolescents (Ahovuo-Saloranta A et al. Sealants for preventing dental decay in the permanent teeth. Cochrane Database of Systematic Reviews 2013, Issue 3. Art. No.: CD001830.)
Ahovuo-Saloranta A et al. 2013
Authors’ conclusions
· The application of sealants is a recommended procedure to prevent or control caries
· Sealing the occlusal surfaces of permanent molars in children and adolescents reduces caries up to 48 months when compared to no sealant, after longer follow-up the quantity and quality of the evidence is reduced
· The review revealed that sealants are effective in high risk children
· The relative effectiveness of different types of sealants has yet to be established
· While resin-based sealants have better retention, there is no evidence to suggest that one type of sealant material is superior to another in terms of caries prevention.
Resin based Fissure Sealants - Safety
· During the mid-1990s safety concerns were expressed regarding leaching of bisphenol-A (BPA) and bisphenol-A dimethacrylate (BPA-DMA) from FS, and a possible oestrogenic effect · Soderholm and Mariotti (1999) concluded that the short term risk of oestrogenic effects from treatments using bispenol-A based resins is insignificant · Fung et al. 2000 showed that BPA released orally from a dental fissure sealants may not be absorbed at all or may only be present in non-detectable amounts in the systemic circulation · A systematic review of pit and fissure sealants (Azarpazhooh, 2008) also states that, “ The evidence suggests that patients are not at risk for exposure to BPA from the use of dental sealants ”
Sealing of Carious Fissures
· Several studies have shown that resin fissure sealants are able to stop further progression of carious lesions in pits and fissures, and even in dentine lesions (Mertz-Fairhurst et al., 1986; Handelman, 1991; Oong et al. 2008; Griffin et al. 2008)
· The rationale for this approach is that the placement of a fissure sealants isolates the carious lesion from the surface biofilm
· Pioneering research by Mertz-Fairhurst demonstrated that sealing over non-cavitated carious lesions is a highly effective treatment.
· The sealant works by cutting off the bacteria from their nutritional supply , thereby arresting the lesion's progression.
· This technique can be used for lesions scored as ICDAS 1, 2, 3, and even 4 .
· Critical Considerations:
a. The Seal Must Be Perfect: A leaking or compromised seal over an active lesion is detrimental and can accelerate decay. Perfect isolation is non-negotiable.
b. Documentation is Essential: The presence of underlying staining/caries must be meticulously documented in the clinical notes, ideally with pre-operative photographs. This prevents a future clinician from misdiagnosing the arrested lesion as active decay and performing unnecessary operative treatment.
· The use should be limited to fissures where the lesion seems to be confined to the enamel, and that dentine lesions should be restored, preferably by the use of minimal intervention techniques, such as the preventive resin restoration (Waggoner and Siegal, 1996; Workshop on Guidelines for Sealant use: recommendations, 1995)
(Welbury et al. 2004; Eggertsson, 2013; Ricketts D, et al. Operative caries management in adults and children. Cochrane Database of Systematic Reviews 2013, 3: CD003808)
Preventive Resin Restoration - PRR
· It 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
· Indication: A tooth with a small, cavitated lesion confined to one part of the fissure system, with other deep, at-risk fissures on the same tooth.
· Technique:
a. Perform a minimally invasive cavity preparation to remove the cavitated lesion, ensuring a peripheral seal zone of sound enamel.
b. Restore the small cavity with composite resin.
c. In the same appointment, apply a pit and fissure sealant to all other connecting and at-risk fissures on the occlusal surface.
· It is good practice to seal other susceptible teeth in the same quadrant at the same time.
Additional Technical Considerations
Filling Level · Underfilled: The fissure pattern is still clearly visible through a thin layer of sealant. · Overfilled: The sealant has flowed up the cusp slopes and onto the marginal ridges, which will interfere with occlusion. · Ideal: The sealant completely fills the pit and fissure system but is contained within the grooves.
Sealing Other Surfaces The concept of sealing is not limited to occlusal surfaces. Always examine and seal other susceptible areas, such as: · Buccal pits of mandibular molars. · Palatal grooves of maxillary molars. · Cingulum pits on anterior teeth. · Anatomical variations like talon cusps or dens evaginatus.
GIC Application Details · Glaze/Coating: After placement, a GIC sealant should be protected with a coating (e.g., G-Coat Plus, cocoa butter, Vaseline) to prevent moisture contamination or dehydration during its initial set. Apply a thin layer; too much can cause a yellow appearance. · Finger Pressure: The ‘finger glove’ technique is an effective way to adapt high-viscosity GIC into fissures. This is not for use with resin composites.