Condition category
Oral Health
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status
Results overdue

Plain English Summary

Background and study aims
In Pediatric Dentistry there is a growing interest in adhesive systems that allow consistent adhesion to enamel and dentin with a shorter working time possible. Self-etch adhesive systems are potential and particularly interesting for clinical practice with children as they can decrease the time of restorative protocol and/or the complexity of the technical steps.
During long, restorative treatments recommended for temporary and permanent teeth were similar because it was thought there were no significant differences both in composition and microstructure of the tissues that form these two types of teeth. However, nowadays these divergences are properly described in the literature and include several differences such as the amount of intertubular dentin, density of tubules and amount of microtubules transverse to dentinal tubules; primary dentin, according to some authors, also features a lower concentration of phosphate and calcium ions. All these facts might hinder or individualize the adhesion process in deciduous dentin and enamel, making it crucial to study and develop specific adhesive restorative strategies equally effective for temporary dentition.
Although all the materials in study are already legally approved for clinical use, does not exist, so far, any publications in indexed journal that embraces an assessment regarding prospective clinic efficacy of different types of adhesives in temporary teeth. Following a line of investigation already initiated that includes in vitro studies, it seems pertinent to analyse, compare and quantify the results obtained with an in vivo study.

Who can participate?
Patients aged 4-8 years with molar lesions

What does the study involve?
Our research group performed a prospective randomized clinical trial to evaluate the clinical effectiveness of three adhesive systems: a self-etch of two steps with selective enamel etching, a self-etch of one step, and an etch-and-rinse system in deciduous dentition at 6, and 12 months.
Participants had standard treatment of tooth lesions. Restoration of the tooth was carried out using one of three different adhesives assigned randomly to participants

What are the possible benefits and risks of participating?
The procedures allows that the existing caries injury is treated with materials that are already legally approved for clinical use, avoiding biological, functional and structural complications that could advise from the non-treatment. There is no increased risk with this clinical procedure since the restorative protocol used is the conventionally recommended and the teeth to be covered need treatment effectively

Where is the study run from?
School of Dentistry, Faculty of Medicine of the University of Coimbra, Portugal

When is the study starting and how long is it expected to run for?
September 2016 to August 2018

Who is funding the study?
University of Coimbra, Portugal

Who is the main contact?
Dr Ana Dani Soares

Trial website

Contact information



Primary contact

Dr Daniela Soares


Contact details

Área de Medicina Dentária
Faculdade de Medicina
Universidade de Coimbra.
Av. Bissaya Barreto
Blocos de Celas
3000-075 Coimbra
+351 239 484183

Additional identifiers

EudraCT number

Nil known number

Nil known

Protocol/serial number

Nil known

Study information

Scientific title

Randomized clinical trial of three adhesives in primary molars restoration


Study hypothesis

Significant differences would be detected among the clinical behavior of the three adhesive systems in primary molars in any of the recall periods (6 and 12 months)

Ethics approval

1. Approved 30/09/2015, Ethics Committee of the Central Hospital of University of Coimbra (Ethics Committee of the Centro Hospitalar e Universitário de Coimbra) (CHUC) (Praceta Prof. Mota Pinto, 3000-075 Coimbra, Portugal; +351 239400400;, ref: CHUC 056-15
2. Approved 25/03/2015, Ethics Committee of Faculty of Medicine, University of Coimbra (FMUC) (Unidade Central, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, Celas, 3000-354 COIMBRA – PORTUGAL;+351 239857700;, ref: CE-010/2015

Study design

Single-center randomized interventional study

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

No participant information sheet available


Oral health, paediatric dentistry


Our research group performed a prospective randomized clinical trial to evaluate the clinical effectiveness of three adhesive systems: a self-etch of two steps with selective enamel etching, a self-etch of one step, and an etch-and-rinse system in deciduous dentition at 6, and 12 months.

Carious lesions removal was ensured with drilling and dentin spoon excavators. The restorative procedures were performed by one single operator. After application of the respective randomly assigned adhesive system under manufacturer's directions a composite resin (Ceram.X® Universal; A3) was placed incrementally and light-cured using a LED-curing unit (S.P.E.C.®3)

Experimental groups:
1. Clearfil™ S3 Bond : Apply adhesive on surface and scrub it in a rubbing motion for 10 s; gentle air-blow for 5 s; light-cure for 10 s
2. Clearfil™ SE Protect Bond: Apply primer and leave undisturbed for 20 s; gentle air-blow for 5 s; apply bonding agente for 10 s; gentle air-blow for 5 s; light-cure for 10 s
3. Prime&Bond® XP: Apply etchant for 15 s; rinse for 15 s; air-dry for 5 s; apply adhesive on surface and wait 20 s; gentle air-blow for 5 s; light-cure for 20 s

One single experienced and calibrated operator performed all restorative treatments. In all cases was made a prior polishing of the tooth with a prophylactic brush and water to remove plaque and salivary film remaining. Was then administered local anesthesia. Isolation with rubber-dam was done in all procedures. After cavity preparation a collaborator selected randomly the adhesive system (Prime&Bond active TM, ClearfilTM S3 Bond Plus and ClearfilTM SE Protect), which was applied according to the manufacturer's instructions. The restorations were made with a light-cured nano hybrid composite resin (Ceram.X®) and with the support of a sectional matrix system (Palodent®Plus) and, applied according to the incremental technique and the manufacturer's indications. Finishing and polishing were made using diamond drills, cups and brushes (Enhance® and Ceram.X® gloss). All the restorations were recorded using digital photography and analyzed by two blinded calibrated evaluators (calibration model approved by the FDI – World Dental Federation) in two different moments: on the day of execution and after 6 months. The evaluation was based on aesthetic, functional and biological factors adapted to the specificity of this study.

Randomisation was performed using a sealed envelope technique

Intervention type



Drug names

Primary outcome measure

Fracture of material and retention measured using the FDI evaluation criteria at baseline, 6 and 12 months

Secondary outcome measures

Using FDI evaluation criteria applied at baseline, 6 and 12 months:
1. Esthetic Properties (surface lustre, marginal and surface staining, anatomical form)
2. Biological Properties (postoperative hypersensitivity and tooth vitality; recurrence of caries; tooth integrity; adjacent mucosa)

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Deciduous molars with caries lesion on the interproximal face with dentinal involvement, without pulp pathology
2. Caries lesion with margins entirely in enamel
3. Presence of antagonistic tooth with occlusal contact
4. Collaborating patients
5. Aged 4 to 8 years
6. Available for compliance with control appointments

Participant type


Age group




Target number of participants

34 participants with carious proximal lesions were initially selected. 101 restorations (at least 33 for research group) in 34 patients were obtained

Total final enrolment


Participant exclusion criteria

1. Teeth with structural changes (such as hypoplasia or hypomineralization)
2. Teeth with mobility
3. Systemic pathology that conditioned oral health (oncological pathology, asthmatics, diabetics, etc.)
4. Taking medicines with recognized oral repercussions
5. Inability of the child and/or parents to ensure proper oral hygiene
6. Presence of periodontitis and/or gingivitis
7. Impossibility of adequate isolation
8. Refusal by parents/legal guardians and/or child (if applicable) to sign informed consent

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

School of Dentistry, Faculty of Medicine of the University of Coimbra
Av. Bissaya Barreto Blocos de Celas

Sponsor information


University of Coimbra (Portugal)

Sponsor details

c/o Ana Daniela dos Santos Soares
Faculty of Medicine
Av. Bissaya Barreto
Blocos de Celas
+351 964313543

Sponsor type




Funder type


Funder name

University of Coimbra (Portugal)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Planned publication in a high-impact peer-reviewed journal.

IPD sharing statement:
All data generated or analysed during this study will be included in the subsequent results publication

Intention to publish date


Participant level data


Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

04/11/2019: Trial’s existence confirmed by Ethics Committee of the Central Hospital of University of Coimbra