Clinical Performance of High Viscous Glass Ionomer Cervical Restorations With Silver-Modified Atraumatic Restorative Technique (SMART) Versus Conventional Treatment in Elderly Cancer Patients. (A 12-month Randomized Clinical Trial)

Adult cancer patients (45-55 years) with primary cervical carious lesions will be recruited from the outpatient clinics of the Faculty of Dentistry, Cairo University. Eligible teeth must be vital by pulp sensitivity testing with controlled periodontal conditions; teeth with previous restorations, irreversible pulpitis signs, mobility, resorption, or cuspal loss will be excluded, as will patients with material allergies, fixed orthodontic appliances, pregnancy, or frequent analgesic use that could mask pain. After signing informed consent, participants will be randomized 1:1using a computer-generated sequence (random.org) with allocation concealed via sequentially numbered, opaque, sealed envelopes. The study is Single blinded ( outcome assessors blinded; the treating operator is not blinded). Baseline data collection includes medical/dental history and pre-operative radiographs. Interventions will be applied by a single trained operator following standardized protocols for SDF/GIC placement (SMART arms) or conventional cavity preparation and GIC placement (control arms). Data will be collected on paper/Excel and analyzed using MedCalc software (v22) with Chi-square, Cochran's Q, one-way ANOVA/Tukey post-hoc, and repeated-measures ANOVA/Bonferroni-corrected comparisons, with significance set at p≤0.05 and 80% power. Sample size (29 teeth/group) was calculated using G*Power based on prior HVGIC retention data. The trial is self-funded, with independent auditing conducted by the co-supervisor.

• Silver Diamine Fluoride (SDF, 38%) (Other): 38% Silver Diamine Fluoride applied to the carious lesion using a micro brush for one minute, followed by application of potassium iodide (KI)Applied in the SMART group 1-3 times until the precipitate clears to reduce black staining, prior to restoration. Used in SMART arm only, with no mechanical removal of carious dentin.
• Conventional Tooth Preparation (Procedure): Conventional mechanical excavation of carious dentin using sharp hand instruments and air-turbine handpiece, burs and excavators; selective caries removal , followed by cavity conditioning with 10% polyacrylic acid, rinsing, and drying, prior to restoration. No SDF is applied in this procedure.
• High-Viscosity Glass Ionomer Cement (Other), also known as HVGIC, RIVA self cure: High-viscosity glass ionomer restorative cement placed and cured according to tooth location, following either SDF application (SMART arm) or conventional mechanical tooth preparation (control arm).

Primary outcomes

• Retention of Restoration [Baseline, 3 months, 6 months, 9 and 12 months]: Evaluation of the presence and integrity of the restoration over the follow-up period, assessed using USPHS criteria (Zhao et al., 2018): Alpha (A) - restoration present; Bravo (B) - partial loss, clinically acceptable; Charlie (C) - clinically unacceptable partial/total loss; Delta (D) - immediate replacement necessary.

Secondary outcomes

• Postoperative Hypersensitivity [Baseline, 3 months, 6 months, 9 and 12 months]: Assessment of patient-reported sensitivity following restoration placement, evaluated using USPHS criteria (Zhao et al., 2018): Alpha (A) - no hypersensitivity; Bravo (B) - mild or transient hypersensitivity; Charlie (C) - moderate or severe hypersensitivity;
• Marginal Integrity [Baseline, 3 months, 6 months,9 and 12 months]: Description: Evaluation of the continuity and adaptation at the restoration margins, assessed using USPHS criteria (Zhao et al., 2018): Alpha (A) - continuity at the margin; Bravo (B) - slight discontinuity at the margin; Charlie (C) - marginal defects requiring replacement.
• Recurrent Caries [Baseline, 3 months, 6 months, 9,and 12 months]: Detection of caries adjacent to restoration margins, assessed using USPHS criteria (Zhao et al., 2018): Alpha (A) - caries absent; Charlie (C) - caries present.
• Average Duration of Treatment [perioperatively]: Time required to complete the restorative procedure, measured in seconds using a stopwatch (Caro et al., 2012).
• Anatomic Form [Baseline, 3 months, 6 months, 9 and 12 months]: Assessment of whether the restoration correctly mimics the natural contours, height, and functional shape of the original tooth, using USPHS criteria (Zhao et al., 2018): Alpha - restoration continuous with existing anatomic form; Bravo - continuous but not exposing cement or dentin; Charlie - sufficient material lost to expose cement material or dentin.
• Color Match [Baseline, 3 months, 6 months, 9 and 12 months]: Measures how well the shade of the restorative material blends with the neighboring natural tooth structure, using USPHS criteria (Zhao et al., 2018): Alpha - no mismatch; Bravo - mismatch within normal range of color, shade, and translucency; Charlie - mismatch outside normal range.
• Surface Roughness and Marginal Discoloration [Baseline, 3 months, 6 months, 9 and 12 months]: Combined assessment of restoration surface smoothness and marginal staining using USPHS criteria (Zhao et al., 2018): Surface roughness scored Alpha (smooth) to Charlie (rough, cannot be refinished); marginal discoloration scored Alpha (none) to Charlie (discoloration penetrated in pulpal direction).
• Patient Satisfaction [Immediately after the intervention, and at 3, 6,9, and 12 months]: Patient-reported satisfaction with treatment, measured using a Visual Analog Scale (VAS) from 0 (unsatisfied) to 10 (totally satisfied), where the patient marks a vertical line across the scale and the distance in millimeters from the zero end is measured (Golpak, 2020).

Sex: All, ages: 45 Years to 55 Years

Inclusion Criteria:

* Patient-related criteria:
* Adult cancer patients of both genders, aged 45-55 years
* Good oral hygiene
* Willing to sign the informed consent
* Co-operative patients who accept the follow-up period

Tooth-related criteria:

* Posterior teeth with primary cervical surface caries, ICDAS score: 4-6
* Normal gingival or periodontal conditions.
* Teeth vital according to pulp sensitivity tests

Exclusion Criteria:

* Patient-related criteria:
* Allergy to any of the restorative materials
* Patients undergoing orthodontic treatment with fixed appliances
* Pregnant women
* Patients who frequently use analgesics or any drugs that could mask pain

Tooth-related criteria:

* Teeth with previous restorations
* Spontaneous or prolonged pain (more than 15 seconds) after cold test, indicating irreversible pulpitis
* Negative sensibility test, periapical radiolucency, or sensitivity to percussion
* Mobile teeth indicating periodontal disease or trauma
* External or internal resorption
* Chipped teeth or cuspal loss