proximal initial caries Introduction minimal invasive restoration

Initial caries: management for minimal intervention

As dentists we should always find the best fitting treatment plan for patients with initial posterior interproximal caries.

Some considerations have to be made when recommending resin infiltration Vs no intervention for posterior initial caries. If the lesion is not cavitated, it is only on enamel and the caries is not active, we recommend no action to be taken. Some clinical parameters could indicate the inactivity of the enamel lesions, so plaque control strategies might be the best choice for compliant patients. Nonetheless, even in low risk patients, it can be assumed that around half of the initial proximal lesions in 15 year old adolescents progress to cavitated lesions at the age of 20 (1). Taking into account the data available in the literature you have all the information to take the best treatment decision.

radiographic classification of carious lesions

Fig.1

Treatment Flowchart for proximal carious lesions.

When the lesion affects only enamel (E1 outer half of enamel, E2 inner half of enamel), resin infiltration is very likely to be enough to stop the carious lesion. If the lesion is cavitated we can only proceed with a composite restoration. The non intervention treatment option could be considered on inactive lesions on compliant patients adhering to plaque control strategies.

radiographic depth classification of carious lesions

Fig.2

When the lesion affects the amelodentin union and goes slightly into the dentin (D1 outer third of dentin) it might still be possible to stop the caries with infiltration if the lesion is not cavitated, even though with less certainty than in case of E1 or E2 lesions. If, instead the lesion is cavitated (frequent situation in D1 caries), we should proceed with mechanical removal of the lesion.

When the lesion is D2 or D3 (medium third or deeper in dentin) the caries is in 100% cavitated, and the only viable treatment option is the turbine and a conventional restoration.

left bitewing X-ray

Fig.3

When deciding between resin infiltration to stop caries versus composite restoration other considerations should be taken into account. Not only the activity and extension of the carious process are to be considered, as it seems that the caries being cavitated or non-cavitated is a very important factor when choosing the therapeutic approach. In cavitated lesions the infiltration technique is contraindicated and we should perform a conventional composite restoration (2).

The main problem in daily practice is that the diagnostic techniques are not suitable for an unmistakeable treatment decision. Even though bitewing X-rays allow us to assess the depth of the lesion – which is a very valuable information – it doesn’t show if a lesion is cavitated or not. Only direct vision and access would allow us to see whether the lesion is cavitated or not.

In this image you can see how a D2 lesion on tooth 14D would be easily diagnosed in this case.

diagnocam proximal caries diagnosis

Fig.4

With the previous image only, I would treat the lesion conventionally with a composite restoration, but, instead with a DiagnoCam we can appreciate an E1-E2 lesion. As only the enamel is affected by demineralization, the resin infiltration technique might be the best option. A complementary diagnosis method is always very useful in dentistry.

right bitting X-ray with baby tooth

Fig.5

I want to show you how with Diagnocam we can improve our caries diagnosis. In this x-ray scan we can see no clear evidence of proximal caries.

laser diagnocam diagnosis proximal caries

Fig.6

In the near-to-infrared image (Diagnocam) we can appreciate a D2 lesion on the mesial of tooth 46.

right bitewing X-ray showing no caries

Fig.7

In the left bitewing we also can’t certainly state any proximal caries is there.

diagnocam image for proximal caries

Fig.8

In the near-to-infrared image (Diagnocam) we can clearly see two D1-D2 lesions on teeth 16M and 15D.

proximal small caries

Fig.9

With the following clinical case we want to show how we manage posterior initial caries, and how we get access to proximal lesions without touching sound structure, and without previous space opening device application. This treatment was performed in a single session.

The premolars on the 3rd quadrant were also affected by initial caries, so we isolated the full arch in order to treat them during the same appointment. Isolation was obtained using the rubber dam (Nictone medium blue, MDC Dental) from lower right first molar to lower left first molar, and fixed with two 27N clamps.

dentech ivory separator for access to caries

Fig.10

Direct vision is obtained thanks to this Ivory Separator (Dentech). The treatment is done in a single visit because no previous tooth separation is needed.With this Ivory separator, teeth are parted as you tighten the screw, thus allowing access to the interproximal space.

accessibile proximal space thanks to ivory separator

Fig.11

The separation allows us to have direct vision of the lesion. The lesion was not cavitated, so we carried out the caries infiltration technique. If the lesion had been cavitated we would have made a conventional composite restoration instead.

airflow cleaning of demineralisation

Fig.12

Cleaning with air-flow (Aquacare by Velopex).

icon etch gel for brown spot

Fig.13

The Icon-Etch was applied on both 45 mesial and 44 distal, which was affected by a E1 lesion. A small brush was used for higher precision (Compobrush, SmileLine).

icon dry syringe for revisualisation of spot removal

Fig.14

The Icon Dry was applied.

etching of brown spot

Fig.15

As we can see, we needed further etching to eliminate the demineralised tissue.

etching gel by DMG for spots

Fig.16

Second Icon-Etch application.

brown proximal spot

Fig.17

Second Icon-dry application.

etching gel for resin infiltration

Fig.18

Third Icon-Etch application.

fading brown spot on premolar

Fig.19

Icon-dry application for the last time. We performed 3 Icon-etch applications for these lesions.

resin application on premolar

Fig.20

Resin application is done with a fine brush (Compobrush, Smile Line), rather than with the applicator.

This extremely thin brush allows for extreme precision. Before light-curing, the excess resin is removed with dental floss. After light-curing a second infiltration step is necessary.

finishing strip for proximal space

Fig.21

To remove resin excess and smoothen the surface we use a finishing strip for proximal areas (Sof-Lex finishing strips, 3M). The grey aluminum oxide grid to remove excess resin, then the white polishing half strip.

white spots on lower molar and cavity

Fig.22

We also treated with the resin infiltration technique the buccal white spots on 46.

We etched three times for the buccal white spots before infiltration, and we used a turbine and composite for the brown spot.

final result after resin infiltration

Fig.23

The final picture.

Conclusions

The best treatment option for initial posterior caries often can’t be chosen until the proximal space is accessible. When choosing between resin infiltration or composite restoration, first opening of the interproximal space is a common approach among most of our colleagues. Most dentists use orthodontic elastics to open the interproximal space 1 day prior to the evaluation, which means two appointments, just for diagnosis. I myself have done this a few times, but this modern approach holds many advantages. With our apporach we can:

– Diagnose on the spot, thanks to the Ivory separator (Dentech)

– Manage the lesion in a single session (no previous tooth separation). Chair times and costs are similar/the same for the different treatment options (resin infiltration/composite restoration).

Bibliography

1. Isaksson H, Alm A, Koch G, Birkhed D, Wendt LK. Caries prelevance in Swedish 20 year old in relation to their previous caries experience. Caries Res. 2013;47(3): 234-42

2. Meyer-Lueckel H, Paris S. When and how to intervene in the caries progress. Oper Dent. 2016;41 (S7): S35-47

3. Kielbassa AM, Muller J, Gernhardt CR (2009) Closing the gap between oral hygiene and minimally invasive dentistry: a review on the resin infiltration technique of incipient (proximal) enamel lesions. Quintessence Int 40: 663-681.

4. Paris S, Meyer-Lueckel H, Kielbassa AM (2007) Resin infiltration of natural caries lesions. J Dent Res 86: 662-666.

5. Paris S, Hopfenmuller W, Meyer-Lueckel H (2010) Resin infiltration of caries lesions: An efficacy randomized trial. J Dent Res 89: 823-826.