Clinical Evaluation of Bioflx Crowns in Restoring Primary Anterior Teeth

forty pediatric patients aged 3 to 5 years presenting with bilateral multi-surface carious primary anterior teeth requiring full coronal restoration are enrolled. Each child receives a Bioflx crown on one target tooth (Group I) and a Celluloid strip crown on the contralateral target tooth (Group II). Clinical outcomes are systematically evaluated at 3, 6, and 9 months post-operative using Modified United States Public Health Service (USPHS) criteria (assessing marginal integrity, color match, restoration integrity/failure rate, and proximal contacts) along with Silness-Löe Plaque and Gingival Indices.

• Bioflx Crown Restoration (Group I) (Procedure): Preparation: Administration of 2% lidocaine local anesthesia with epinephrine; caries removal; 1-1.5 mm incisal reduction; 1 mm mesial/distal contact breaking using diamond burs; minimal labial/palatal reduction; rounding of sharp line angles. Seating \& Cementation: Selection of appropriate Bioflx crown size via mesiodistal caliper measurement; crown try-in; cavity sealing and final cementation using self-curing glass ionomer cement (IMICRYL Nova); excess cement removal with explorer and dental floss.
• Celluloid Strip Crown Restoration (Group II) (Procedure): Preparation: Local anesthesia administration; caries removal; shade selection; incisal and proximal reduction. Matrix \& Bonding: Celluloid strip crown form selected, trimmed to length, verified for cervical adaptation, and vented at the incisal edge. Enamel etched with 37% phosphoric acid (CharmEtch) for 15 seconds, rinsed, and dried. Universal bonding agent (All-Bond Universal) applied and light-cured for 15 seconds. Placement \& Finishing: Crown form filled with shade-matched composite resin (Beautifil), seated firmly on the tooth, excess material removed, and light-cured. Celluloid form stripped off using an excavator; final polishing performed.

Primary outcomes

• Cumulative Restoration Success Rate via Modified USPHS Criteria [Evaluated at 3, 6, and 9 months post-operative.]: Proportion of restored crowns categorized as clinically successful (expressed as a percentage). Restoration success is defined as achieving Alpha (A) or Bravo (B) ratings across all four Modified USPHS parameters evaluated via visual, explorer, and dental floss inspection: 1. Marginal Integrity (Alpha = smooth adaptation; Bravo = explorer catches); 2. Color Match (Alpha = exact match; Bravo = acceptable mismatch); 3. Restoration Integrity (Alpha = intact; Bravo = small material loss); 4. Proximal Contact (Alpha = normal resistance to floss; Bravo = contact present without resistance). A rating of Charlie (C) or Delta (D) in any single parameter constitutes restoration failure.

Secondary outcomes

• Gingival Health Response (Gingival Index) [Evaluated at baseline, 3, 6, and 9 months post-operative.]: Measure Description: Evaluation of marginal gingival tissue health surrounding each restored crown using the Löe and Silness Gingival Index (GI) scored from 0 to 3 (0 = Normal gingiva; 1 = Mild inflammation/slight edema; 2 = Moderate inflammation/erythema/bleeding on probing; 3 = Severe inflammation/spontaneous bleeding).
• Plaque Index Score around Restored Teeth [Evaluated at baseline, 3, 6, and 9 months post-operative.]: Measure Description: Assessment of soft microbial plaque thickness at the gingival margin surrounding each crown using the Silness-Löe Plaque Index (PI) scored from 0 to 3 (0 = No plaque; 1 = Thin film at gingival margin; 2 = Moderate accumulation; 3 = Abundance of plaque).

Sex: All, ages: 3 Years to 5 Years

Inclusion Criteria:

* Healthy children aged 3-5 years with cooperative behavior (Frankl's behavior rating scale 3-4).
* Bilateral anterior primary teeth affected by multi-surface caries requiring full coronal restoration.
* At least two-thirds of the root structure is present, and adequate coronal tooth structure to retain the crown.

Exclusion Criteria:

* Non-restorable teeth
* Teeth with single-surface restorations.
* Previous full-coverage restoration or large unsuccessful restoration on the target tooth.
* Children with oral parafunctional habits (e.g., thumb sucking, bruxism).
* Advanced physiologic root resorption (>1/3).

• Results publication: Patil AS, Jain M, Choubey S, Patil M, Chunawala Y. Comparative evaluation of clinical success of Stainless Steel and Bioflx crowns in primary molar - A 12 month split mouth prospective randomized clinical trial. J Indian Soc Pedod Prev Dent. 2024 Jan 1;42(1):37-45. doi: 10.4103/JISPPD.JISPPD_484_23. Epub 2024 Apr 15. PMID 38616425
• Results publication: Agrawal R, Khanduja R, Singhal M, Gupta S, Kaushik M. Clinical Evaluation of Stainless Steel Crown versus Zirconia Crown in Primary Molars: An In Vivo Study. Int J Clin Pediatr Dent. 2022 Jan-Feb;15(1):15-19. doi: 10.5005/jp-journals-10005-2134. PMID 35528499