Four year Evaluation of Proximal Resin Infiltration in Adolescents

Abstract

Aim

Resin infiltration of proximal lesions is a new approach to stopping caries progression. Therefore, the aim of the present study was to evaluate four-year efficacy of proximal infiltrates in adolescents.

Materials and methods

In ten adolescents, a total of 21 proximal infiltrates (ICON® (DMG, Germany) were applied to initial proximal lesions of permanent incisors and premolars according to the manufacturer’s instruction. The clinical quality of resin infiltration was assessed at 1 week, 1, 2, 3 and 4 years after the treatment and the evaluation of the therapeutic effect was analyzed by radiographs.

Results

Ten patients were followed up clinically for four years. The majority of the infiltrated lesions were located on permanent incisors. Teeth which were proximally infiltrated did not exhibit dental plaque and gingival bleeding in most cases. At annual recalls, plaque scores remained constant. The gingival status remained steady and no differences in tooth shape and contour were detected. Discoloration was detected in four teeth (19%) in 1st year recall and was constant at annual intervals. The radiographic evaluation of the bitewing radiographs showed no progression in 21 lesions (100%) from baseline to the 4-year recall. Overall oral hygiene of the patients was satisfactory.

Conclusion

In conclusion, proximal infiltration is an effective prophylactic measure in adolescents.

Introduction:

Early proximal caries lesions pose a serious problem in adolescence (1). While early diagnosis of these lesions is vital, it is also important to preserve the lesion surface from acidogenic bacteria and carbohydrates. Recently, proximal sealing with glass-ionomer cement, composite resin, bonding material and polyurethane patch offered good results in proximal lesions directing researchers in new material search (2-6). Apart from the abovementioned idea of proximal caries sealing, there is the term ‘caries infiltration’ where the porosities of the lesion body are further penetrated by low viscosity light curing resins, so called ‘infiltrates’ (7). There is a limited number of studies dealing with the infiltration technique (8-13). The results of these studies are promising, highlighting its high efficiency in reducing caries progression, requirement of only one visit and an applicable method. However, more evidence is needed to see the long-term results of infiltrates. Therefore the aim of the present study was to evaluate the 4-year efficacy of infiltrates in adolescence.

Materials and methods

Ten adolescents (6 F, 4 M, age range 14-17 years) participated in the study. Inclusion criteria: to have a proximal lesion in the enamel or in the outer third of the dentine on a permanent tooth assessed radiographically. Exclusion criteria were: systemic diseases, allergies and presence of visible or detectable cavitation on the tested proximal surfaces.

All the patients and their parents who participated in the present study received detailed information about the procedure and were required to give an informed consent. The bitewing radiographs were taken with digital x-ray (Vista Scan, Dürr Dental, USA). The classification of 21 proximal lesions was made according to the following criteria: radiolucency in the outer half of the enamel (E1), radiolucency in the inner half of the enamel (E2), and radiolucency with obvious spread in the outer third of dentin (D1) according to Paris et al. (12). Radiolucency with obvious spread in the middle third of dentin (D2) or in the inner third of dentin (D3) was not allowed in the study. The medical history and the dental status were assessed during the baseline evaluation.

Regarding evaluation of oral health status, plaque accumulation, caries and gingival status of the tested teeth were recorded prior to treatment. The clinical status was scored as healthy (0), initial carious lesion (1), while carious defects (2) were not allowed at baseline. Plaque accumulation was scored as no visible plaque (1), mild (2), moderate (3), excessive plaque (4). The gingival status was scored as healthy (1), bleeding after probing with a WHO probe (2), swelling (3), and strongly inflamed with profuse bleeding (4). All the patients were recall patients where brushing habits, dietary controls and recent fluoride applications were recorded.

Two trained pediatric dentists applied the resin infiltration according to the manufactures’ instructions following the flow chart on the box (Icon^® Proximal Mini Kit, DMG, Hamburg, Germany). After separation with the included wedge, the proximal surface of the test tooth was etched with 15% hydrochloric acid for 120 s using the special proximal applicator, which is permeable only on one side (Icon^® Proximal Mini Kit, DMG, Hamburg, Germany). The proximal surface was rinsed with water and dried for 30 s according to the manufacturer’s instructions. The surface was dehydrated by evaporation of superficially applied 95% ethanol and continuous air-drying for 30 seconds. The very low viscosity resin, the infiltrate, (Icon^® Proximal Mini Kit, DMG, Hamburg, Germany) was applied to the test lesion for 180 s using another enclosed proximal applicator which is also permeable only on one side. After removal of excess material using dental floss, the infiltrate was light-cured (Mini L.E.D^®, Sirona, Bensheim, Germany) from all sides for 40 s according to the manufacturer’s instructions. The infiltrate was reapplied for 60 s and light-cured. Finally, the contour of the proximal surface was finished and polished with finishing discs and polishing strips (Soft-Lex, 3M ESPE, MN, USA).

The clinical evaluation check of the resin infiltration was assessed by the same examiners at baseline. Patients were clinically re-examined after one week, one, two, three and four years within invitation from the recall system. The same dentists performed the subsequent recalls. The interexaminer calibration was 0.90 (kappa score). The clinical status, plaque accumulation and gingivitis were recorded according to the same criteria used at baseline. In order to assess the quality of the resin infiltration, the discoloration and marginal adaptation tests were recorded according to the following criteria which have been subdivided from USPHS criteria. Discoloration of the infiltrated surfaces was scored as no discoloration -1-, partial discoloration at the margins -2-, discoloration of the whole surface -3-. The marginal adaptation was recorded as follows: 1 Smooth transition (no detectable margins); 2 Sharp-edged margins.

All data were entered into a SPSS software (SPSS16.0 for windows, SPSS Inc. Chicago, IL, USA) for statistical analysis. Descriptive statistics and frequencies were performed regardless the type of data. The proportions of baseline and recalls data were compared by Friedman test. In all tests, p values below 0.05 were defined as statistically significant.

Results

Ten patients were followed up clinically. The majority of the infiltrated lesions were located on permanent incisors (Table 1). From 21 lesions, three of them were categorized as E1, 10 were categorized as E2 and eight of them were noted as D1. The mean DMF-S of the sample was 7.3 ± 2.9 corresponding to a DMF-T of 4.1.8 ± 2.2. Adolescents were given oral hygiene education and dietary counselling. Only patients under annual recall system were included in the study. All patients were instructed to use dental floss. Teeth which were proximally infiltrated did not exhibit dental plaque and gingival bleeding in most patients (Table 2). At annual recalls, plaque scores remained constantly. The gingival status remained steady and no difference in tooth shape and contour were detected. Discoloration was detected in four teeth (%19) in 1st year recall and was constant in annual intervals (Table 2). Marginal adaptation was proper and smooth in all cases in all time intervals. There were no sharp edges detected. There was no statistical difference in any parameters between any time intervals (p>0.005). The radiographic evaluation of the bitewing radiographs showed no progression. 21 lesions (100%) were followed from baseline to the 4-year recall. Overall oral hygiene of the patients was satisfactory.

Table 1. Distribution of the infiltrated lesions according to tooth type and surface.

	N	%
Permanent incisors (m)	7	33.3
Permanent incisors (d)	8	38.1
Permanent premolars (m)	3	14.3
Permanent premolars (d)	3	14.3

Table 2. Plaque accumulation, gingival status and clinical duration of the infiltrations at the 1-week, 1, 2, 3 and 4 year recalls.

USPHS Criteria	Code	1 week	1 year	2 years	3 years	4 years	P
		N (%)	N (%)	N (%)	N (%)	N (%)
Plaque accumulation	1 no plaque 2 mild 3 moderate 4 excessive	21 (100%) 0 0 0	19(90.5%) 2 (9.5%) 0 0	20(95.3%) 1 (4.7%) 0 0	21 (100%) 1 (4.7%) 0 0	19(90.5%) 2 (9.5%) 0 0	1.00
Gingiva status	1 healthy 2 bleeding 3 swelling 4 excessive	21 (100%) 0 0 0	21 (100%) 0 0 0	20(95.3%) 1 (4.7%) 0 0	21 (100%) 0 0 0	21 (100%) 0 0 0	1.00
Discoloration	1 sound 2 partial discoloration 3 whole discoloration	21 (100%) 0 0	17 (81%) 4 (19%) 0	17 (81%) 4 (19%) 0	17 (81%) 4 (19%) 0	17 (81%) 4 (19%) 0	0.06
Marginal adaptation	1 smooth 2 sharp	21 (100%) 0	21 (100%) 0	21 (100%) 0	21 (100%) 0	21 (100%) 0	1.00

NS

Discussion

Epidemiological data show that the prevalence of caries on proximal surfaces in need of surgical treatment is very high around the world, both in the primary and the permanent dentition (14). Caries infiltration stands to be a new, easy approach to stabilize the progression of initial, noncavitated proximal lesions (15). In the present study, no visible cavitation was included. Only two calibrated pediatric dentists applied the technique and followed the patients for four consecutive years. The patients controlled in the study did not present any new caries lesions.

Recently it was stated that ‘marginal integrity and color match were always considered important factors to assess the quality of posterior composites and, therefore, the widely used USPHS criteria were adapted for the micro-invasive infiltration technique in order to allow a comparison with the infiltration’ (16). In the present study regarding plaque accumulation, gingival status and clinical duration of the infiltrations, the results were totally efficient where infiltrants were plaque free, gingival tissue was healthy and there was no bleeding during controls. There was no loss of infiltrations. Regarding radiographs, there were no caries progressions detected. The present paper finds discoloration a problem where patient satisfaction may be a cause of infiltrate failure.

The present study considers proximal infiltration as an efficient way to reduce caries progression. These results are consistent with recent long term studies (17, 18) where progression of proximal non-cavitated caries lesions was efficiently arrested with proximal infiltration. Recently it was stated that infiltrates may lead to discoloration in early stages but this position may be reduced in subsequent months (19, 20). In the present study, at annual intervals one of the patients wished to have an esthetic dental filling at the end of four years.

The present study lacks a higher number of cases since a 4-year evaluation needs cooperative control patients. However, because of high oral hygiene quality, the results are satisfactory.

In conclusion, proximal infiltration is an effective prophylactic measure in adolescents.