Microinvasive Therapy: 16 Sealing of Approximal Surfaces
The general decrease in caries experience among children and adolescents in the past 30 years1 is based on a marked decrease in the most susceptible sites (occlusal surfaces), however, with a relative increase of lesions in the approximal and smooth surfaces.2,3 Studies on young Swedish and Danish adults have shown that, even under strict preventive community measures, slow but continuous progression of approximal caries lesions from enamel into dentin can still be observed.4,5 In a Swedish cohort of 11- to 13-year-olds proportion of those without radiographically apparent caries lesions increased from 28% to 71% within 8 years.4 Also, in young adults in Denmark, approximal caries progressed. Over a 6-year period in 57% out of 73 young male adults, approximal lesions initially located in the enamel and extending up to the outer third of the dentin progressed or were restored.5
Thus, it seems that if approximal caries has developed it will progress, but slowly. One of the main reasons for this is the lack of patients’ adherence in using dental floss.6 It might be advisable to do some kind of more invasive treatment at some point. However, due to the impaired access to approximal caries lesions, not only their detection but also their restorative treatment is difficult. Often the removal of large amounts of sound enamel and dentin is necessary to “treat” the caries lesions. Owing to this unfavorable ratio for sound fissures, it is desirable to postpone the first invasive intervention for as long as possible and to arrest lesion progression by microinvasive measures, such as approximal sealing.
This chapter will cover in detail:
-
The transfer of the sealing technique from the occlusal to the approximal surface
-
Clinical procedures and dental materials to conduct approximal sealing
-
Up-to-date knowledge on the efficacy and indication of approximal sealing
Transfer of the Sealing Technique from the Occlusal to the Approximal Surface
Three recent developments have led to the transfer of sealing techniques from occlusal to approximal surfaces:
-
The perception that conventional noninvasive measures alone may not be capable of preventing lesion progression of approximal caries lesions in every individual.7–11
-
The growing evidence on the efficacy of sealants to arrest caries progression on occlusal surfaces (see Chapter 15). Thus, for some years now, it has been widely recommended to seal initial carious lesions on occlusal surfaces, involving caries lesions with a radiographic severity from deep enamel lesions to lesions into the outer part of the dentin.9–16
-
The third incentive for introducing sealing techniques for approximal caries lesions has been the prospect of better feasibility, by adopting tooth separation techniques from orthodontics. Hereby, lesion characteristics can be more easily assessed,17 and materials used for sealing can be satisfactorily applied to the approximal surfaces.
These aspects led to the implementation of the sealing technique for approximal caries lesions, using adhesives or sealants.18–20 Another method involves the application of an adhesive “patch” onto the enamel surface.21 More recently, an infiltration method has been developed in particular for approximal caries lesions.22 This chapter will focus on the sealing methods using either adhesives/sealants or adhesives in combination with the so-called patch.
Clinical Procedure
Which Approximal Lesions Should Be Sealed?
Diagnosis is an important first step before the treatment decision (see Chapters 5–9). As the visual–tactile accessibility of the approximal surfaces of posterior teeth is impaired, bitewing radiographs are used for the detection and assessment of the lesion depth, which correlate fairly well to the histological extension of the demineralization process23,24 (see Chapter 3). Three main questions that relate to the decision to seal or not to seal approximal lesions need to be answered (see also Chapter 20).
-
Is the lesion too deep or too shallow to be treated by sealants?
-
Shallow approximal lesions (confined histologically to enamel) will most likely be arrested by noninvasive measures only. These lesions can be detected on the radiograph as radiolucencies into the outer enamel.
-
A lesion which has extended radiographically into inner enamel or at maximum up to the outer third of the dentin would be suitable for sealing.
-
For deeper lesions radiographically into the middle third or deeper into the dentin, an invasive treatment should be recommended.11,14,25,26
-
-
Is there a way to confirm that no cavity is present?
-
The depth of the radiolucency correlates fairly well with the probability of clinical cavitations being present.23–25 A visual–tactile assessment of the caries lesion will allow for the detection of a cavity and should reinforce the radiographic assessment. This visual–tactile examination is conducted after a two day temporary separation of the affected teeth ( Fig. 16.1 ) using, for example, the ICDAS visual criteria,27 or if it is not possible to do this assessment at a second appointment, it can be done by using a thin probe to evaluate whether there is a clinically detectable surface breakdown.
-
If the caries lesion has a white/brown opacity with, at the most, a slight surface breakdown in enamel, and the radiolucency depth extends at maximum into the outer dentinal third, sealing is recommended.11
-
If there is a surface breakdown or a distinctive cavity with exposition of the dentin and the radiolucency extends the outer dentinal third, then invasive treatment is recommended.11,26
-
-
Is it possible to assess if the caries lesion will progress in the future?
Techniques for Approximal Sealing
Sealing Procedure19
To gain access to the approximal lesions, an orthodontic band is placed between the teeth for 2 days. In a second appointment, the band is removed and the lesion is cleaned with a solo-brush and dental floss. Cotton rolls are used to ensure relative dryness of the area. A wooden wedge is placed between the teeth to maintain the gained space and to absorb any excess of sealant; the neighboring tooth surface is covered with Teflon tape. Then the following treatment steps are performed ( Fig. 16.2 ):
-
Etching of the surface with 37% phosphoric acid for 15 seconds
-
Thorough water-rinsing and air drying
-
Repeating of isolation using the Teflon tape
-
Application of the adhesive with a micro-brush and dental floss
-
Removal of excess material with dental floss
a, bElective temporary separation. (Fig. 16.1a with permission from Schweizer Monatsschrift für Zahnmedizin; Meyer-Lückel H, Fejerskov O, Paris S., Forschung-Wissenschaft-Recherche-Science 2009; 5:454-460.) a Placement of an elastic band for 2 days. b Visual/tactile access to an approximal lesion. -
Re-application of the adhesive
-
5-second air drying from a distance
-
Light curing from lingual/palatal and from buccal directions
-
Polishing
In a Swedish study approximal sealing was performed quite similarly, also after tooth separation.20
Stay updated, free dental videos. Join our Telegram channel
VIDEdental - Online dental courses
