: Assessment of Clinical, Radiographic, and Oral Health-Related Quality of Life Following Restoration of First Permanent Molars with Cention N: A 12-Month Split-Mouth Randomized Controlled Trial

Introduction

Dental caries is one of the most common chronic diseases affecting children. First permanent molars (FPMs) are particularly susceptible to caries because of their early eruption and complex occlusal anatomy. Restorative treatment aims to preserve tooth function and prevent disease progression. Composite resin is widely used because of its esthetics and mechanical properties; however, polymerization shrinkage may compromise marginal integrity. Cention N is a newer alkasite restorative material that releases fluoride, calcium, and hydroxide ions, promoting remineralization and enhancing caries resistance. Since treatment success should include both clinical outcomes and patient-centered outcomes, oral health-related quality of life (OHRQoL) will also be assessed.

Aim

To compare the clinical and radiographic performance of Cention N and bioactive injectable resin composite in restoring first permanent molars over 12 months. A secondary objective is to evaluate changes in children's oral health-related quality of life.

Materials and Methods

This will be a split-mouth randomized controlled clinical trial involving 100 children aged 8-10 years.

Inclusion criteria:

Healthy children (ASA I or II). Positive/definitely positive behavior (Frankl 3 or 4). Bilateral carious first permanent molars. Vital, asymptomatic teeth without radiographic pathology.

Exclusion criteria:

Lack of parental consent. ASA III or higher. Teeth with signs of irreversible pulp disease or radiographic pathology.

Ethical approval will be obtained from the Research Ethics Committee, Faculty of Dentistry, Minia University, and written informed consent will be obtained from parents.

Clinical Procedure

Following clinical and radiographic examination, local anesthesia and rubber dam isolation will be performed. Caries will be removed conservatively, followed by acid etching and adhesive application.

One molar will be restored with bioactive injectable resin composite according to the manufacturer's instructions.

The contralateral molar will be restored with Cention N, mixed and placed according to the manufacturer's instructions, with optional light curing.

All restorations will be finished and polished using standardized procedures.

Outcome Assessment

Primary outcome

Clinical and radiographic evaluation at 3, 6, and 12 months using the modified USPHS criteria, including:

Color match Marginal adaptation Marginal discoloration Anatomic form Secondary caries Restoration integrity

Secondary outcome Assessment of oral health-related quality of life using the Child Perceptions Questionnaire (CPQ8-10), which evaluates oral symptoms, functional limitations, emotional well-being, and social well-being.

Statistical Analysis

Collected data will be tabulated and analyzed using appropriate statistical methods to compare the performance of both restorative materials over the follow-up period.

Assessment of Clinical, Radiographic, and Oral Health-Related Quality of Life following restoration of First Permanent Molars with Cention-N: A 12-Month Split-Mouth Randomized Controlled Trial

Introduction

Dental caries is a prevalent chronic disease resulting from the interaction of acid-producing bacteria, fermentable carbohydrates, and host-related factors such as saliva and tooth morphology.

The first permanent molar (FPM) is recognized as one of the most caries-susceptible teeth in the mixed dentition. Its early eruption and the morphology of its occlusal surface make it highly prone to plaque retention and early carious involvement shortly after emergence.

Managing caries on the occlusal surfaces of permanent molars remains a clinical challenge, as these teeth consistently demonstrate the highest caries prevalence among permanent teeth.

Restorative treatment is required when carious lesions cause pain, functional impairment, or aesthetic concerns. Adhesive restorative materials provide durable sealing and bonding, which help arrest disease progression. Furthermore, achieving a smooth tooth-restoration interface is essential to support effective plaque control and reduce the risk of secondary caries.

A variety of tooth-colored restorative materials are available. The selection of an appropriate material should be guided by factors such as longevity and survival rate, esthetic qualities, physical characteristics, and overall biocompatibility.

Among tooth-colored restorative options, composite resins are widely used due to their esthetics, mechanical strength, and micromechanical bonding. However, polymerization shrinkage remains a limitation affecting marginal integrity.

More recently, Cention N has been introduced as an "alkaline" tooth-colored restorative material designed for bulk placement. It is a self-curing, UDMA-based material with optional light curing, incorporating alkaline glass fillers that release fluoride, calcium, and hydroxide ions, thereby supporting remineralization and enhancing caries resistance. With its radiopacity, high strength, and dense polymer network, Cention N presents a promising alternative to conventional composites.

Oral health-related quality of life (OHRQoL) reflects how oral conditions and their management influence daily functioning, well-being, and overall quality of life, providing a framework for a comprehensive evaluation of restorative outcome.

Given the advantages and limitations of both materials, the current research seeks to assess bioactive injectable composite (Shofu) and Cention N (Ivoclar Vivadent, Starter Kit) in restoring first permanent molars, thereby providing evidence-based guidance for material selection in children, as the success of restorative treatment extends beyond clinical outcomes to include the child's perception of oral health.

Aim of the study

The primary outcome of this study is the assessment of the clinical and radiographic performance of Cention N vs. resin composite in restorations of first permanent molars, while the secondary outcome is the evaluation of oral health-related quality of life (OHRQoL).

Materials and methods

This study is a 12-month split-mouth randomized controlled clinical trial designed to compare the clinical performance of Cention N and resin composite in restoring carious first permanent molars in children. The secondary objective is to evaluate the effect of both restorative materials on oral health-related quality of life (OHRQoL). The split-mouth design allows each participant to serve as their own control, thereby minimizing inter-individual variability.

Prior to treatment, the child and parent or guardian will receive an age-appropriate explanation of the clinical procedures, and behavior management techniques will be used to facilitate patient cooperation. A comprehensive clinical examination will be performed to determine the extent of the carious lesion and confirm the treatment plan.

When indicated, local anesthesia will be administered according to the child's body weight, medical history, and anticipated treatment duration. Before injection, the oral mucosa will be dried with sterile gauze, and 20% benzocaine topical anesthetic will be applied for 30-60 seconds to minimize discomfort. Inferior alveolar nerve block with long buccal nerve anesthesia will be used for mandibular molars, while local infiltration anesthesia will be administered for maxillary molars.

All restorative procedures will be performed under rubber dam isolation to ensure adequate moisture control. Before placement, patients will be screened for latex allergy, and a latex-free rubber dam will be used when required. A mouth prop will be used when necessary to improve patient comfort and access. Rubber dam isolation will be achieved using an appropriate molar clamp secured with dental floss as a safety ligature. A single hole will be punched for the treated tooth, the clamp will be positioned and checked for stability, and the rubber dam will be stretched over the clamp and secured to the frame. Interproximal contacts will be checked with dental floss to ensure proper isolation and patient comfort.

Cavity preparation will be carried out using standardized minimally invasive principles. Carious tissue will be removed using a high-speed diamond bur under continuous water coolant. The cavity walls will then be refined to obtain a sound cavity preparation suitable for adhesive restoration.

Following cavity preparation, enamel margins will be etched with 37% phosphoric acid for 30 seconds, thoroughly rinsed with an air-water spray for at least 30 seconds, and gently dried using oil-free compressed air. A dental adhesive system will then be applied according to the manufacturer's instructions and light-cured for 20 seconds before placement of the restorative material.

For teeth allocated to the resin composite group, Composite is applied directly out of the syringe into the cavity. It will be light-cured for 20 seconds to achieve adequate polymerization. Following placement, the restoration will be finished and polished to establish proper anatomical contour, marginal adaptation, and surface smoothness.

For teeth allocated to the Cention N group, the restorative material will be hand-mixed on a mixing pad using the manufacturer's recommended powder-to-liquid ratio of one scoop of powder to one drop of liquid (by volume). The material will be inserted into the prepared cavity, carefully adapted to the cavity walls, and condensed to optimize internal adaptation and marginal integrity. Optional light curing for 20 seconds will be performed according to the manufacturer's instructions to enhance polymerization and surface hardness. After complete setting, finishing and polishing procedures will be carried out to obtain appropriate anatomical form, occlusal harmony, and a smooth restoration surface.

All restorative procedures will be performed by the same trained operator using standardized clinical protocols to ensure consistency throughout the study. Participants will attend scheduled follow-up visits during the 12-month study period for assessment of restoration performance and evaluation of oral health-related quality of life using a validated questionnaire.

Inclusion Criteria:

Clinical:

1. Children aged 8-10 years.
2. Children classified as ASA physical status I or II.
3. Children demonstrate positive or definitely positive behavior (scores 3 or 4 on the Frankl Behavior Rating Scale).
4. Children who are available for regular recall visits throughout the study period.
5. Presence of bilateral carious lesions in permanent first molars, with a clear description of lesion depth whenever possible.
6. Asymptomatic vital permanent first molars showing no clinical or radiographic signs of pathology.

Radiographic:

1. Normal lamina dura and periodontal ligament space.
2. No apical radiolucency.

Exclusion Criteria:

Clinical:

1. Children with behavioral difficulties or without signed parental consent.
2. Children are classified as ASA physical status class III or higher.
3. Teeth presenting clinical signs of pulpitis or necrosis (e.g., nocturnal pain, fistula, abscess, pulp exposure, or pathological mobility).

Radiographic:

1. Evidence of abnormal radiolucency involving the pulp chamber or root apex.
2. Detection of furcal bone radiolucency or abnormal root resorption.