Lesion Progression of Approximal Caries After Resin Infiltration

The aim of the planned in-vivo trial is to investigate the effectiveness of the the caries
infiltration technique for the repression of approximal caries progression. .

Within the framework of this investigation it is intended that the hypothesis be
substantiated that carious cavities, which have been treated with the caries infiltration
technique, exhibit significantly reduced radiological progression than those cavities that
have been treated using standard treatments.

Modern dentistry, which is focused more towards preventive and minimally invasive
treatment, attempts - with the aid of fluoride therapies and improved oral hygiene - to
prevent the onset and progression of carious lesions as much as possible.

Even today, approximal lesions pose a particular problem to the treating dentist. A primary
reason for this is the difficulty accessing the localized area of the carious cavity.
Treating this area usually requires invasive treatment, in which healthy tooth structure
must be removed. Furthermore, it is possible that the filling material may deteriorate as a
result of the aging process, meaning that the restoration will require replacement at some
point in the future. In order to prevent this, the development of a treatment oriented
towards prevention and minimal invasion is key.

For a number of years there has been an option to seal pits and fissures on the occlusal
surfaces, which is assessed in the literature as being highly efficacious and effective
(Splieth et al. 2010, Ahovuo-Saloranta et al. 2008, Griffin et al. 2008). It constitutes a
vital component of the caries prevention approach especially in the event of an increased
risk of caries (Hiiri et al. 2010). In recent years there has been an attempt to transfer
this treatment concept to applications in the approximal area, in order to prevent
unnecessary substance ablation. A fissure sealing resin and a dental adhesive were used for
the first time in an attempt at creating a surface diffusion barrier (Gomez et al. 2008,
Gomez et al. 2005, Paris et al. 2006, Martignon et al. 2006, Robinson et al. 2001). Coating
the tooth surface in the approximal area with various plastic foils after tooth separation
opened up a whole new treatment approach for dealing with these carious lesions (Alkilzy
et al. 2010, 2009).

The caries infiltration technique constitutes an additional new treatment concept. Here, the
surface alone is not exclusively coated but a diffusion barrier is instead created inside
the cavity itself, through the penetration of the "infiltrant" into the carious lesion
(Paris et al. 2010, Meyer-Lueckel et al. 2010, 2009, 2008, Phark et al. 2009). In current
studies, it has been possible to demonstrate inhibition of the progression of carious
lesions with the infiltration technique, both in bovine teeth in situ and in artificially
generated carious lesions in human teeth in vitro (Paris et al. 2010).

The development of the infiltration technique started back in the 1970's with the first
low-viscosity plastic materials. However, these were never put into clinical application due
to their toxicity (Robinson et al.1976). During their course of development, adhesive
systems were employed for sealing carious lesions (Donly et al. 1992, Garcia-Godoy et al.
1997). These also exhibit a caries-inhibiting effect. However, it has only been possible to
determine limited penetration depths. The reason for this is the surface morphology of the
carious cavity, with a very limited pore volume on the surface, and the characteristics of
the adhesive itself (Paris et al. 2007). In order to facilitate removal of the limiting
surface layer, a hydrochloric acid gel was used for the infiltration technique in place of
orthophosphoric acid gel for the adhesive technology. Using this conditioner it was possible
to guarantee better penetration of the materials up to a depth of 58 µm due to an erosive
removal of the surface layer (Meyer-Lueckel et al. 2007, Paris et al. 2007, 2009). In order
to better utilize the capillary effect in the altered surface and to thereby increase the
penetration depth of the material, monomer mixtures were developed with a high penetration
coefficient. These enable a fast penetration of the infiltrant into the altered carious
surface up to a depth of 750 µm (Paris et al. 2007, 2009). The sealing of the carious cavity
is now no longer restricted to the surface alone, but also encompasses the body of the
cavity.

The anticipated result of this trial shall deliver information on the long-term
effectiveness of caries infiltration and thereby result in an improvement in caries
prevention within the scope of dental treatment, and prevent the progression of existing
carious lesions . This is a micro-invasive form of treatment, which largely facilitates the
delay or avoidance of conventional invasive initial dental treatment with the associated
inevitable loss of healthy tooth structure. Further studies on the optimization of the
infiltration technique can be built upon these results. In the long-term, it will be
possible to use these findings to develop new prevention and treatment options for
approximal carious lesion .

Inclusion Criteria:

- Age: 18 years and older

- Good general health

- At least 2 active, approximal caries lesions present without evidence of frank
cavitation Caries depth: E2 - D1 (minimum extension to the inner half of the enamel
and maximum to the outer third of the dentin)

- The posterior teeth on the upper and lower arches from distal of the first premolar
to mesial of the second molar will be included

- All teeth to be treated must have approximal contacts with the adjacent teeth in the
arch

- Other teeth requiring treatment will be treated prior to the beginning of the trial

- The patients must declare their consent to participate in the clinical trial
following the provision of the required clarifications regarding the method,
significance and scope of the trial as well as the associated risks. They may
withdraw this consent at any time.

- Participation in the follow-up examinations

Exclusion Criteria:

- - Parallel participation in a further trial relating to dental materials

- The patient has not signed the participant consent form

- Pregnant and breastfeeding women prior to the trial commencing A woman that becomes
pregnant after the treatment has been performed will remain in the study, unless she
becomes pregnant for a second time in which case, she will be excluded from the study

- Unexplained diseases of the mucous membranes or conditions in the sense of contact
allergies to materials used, e.g. oral lichenoid lesions

- Known allergies to ingredients contained within the treatment materials used

- Infectious diseases such as HIV, hepatitis, etc

- Undergoing orthodontic treatment at the time of the trial

- Persons who are presently taking other medication due to other illnesses, which upon
our examination are deemed to possibly be a risk or a problem for the patient or the
study

- A large number of existing carious lesions that have not been restored and would
require extensive treatment, comprehensive prosthetic restorations that need to be
done or replaced and severe periodontal disease

- Current use of bleaching products or use within the two weeks previous to the start
of the study

- No assured dry isolation possible as required per the criteria of the adhesive
technology (rubber dam system)

- Persons with a history of allergies

- Patients with dental treatment phobias