Porcelain sculptures are delicate works of art that can develop cracks over time due to handling, environmental factors, or accidental damage. Restoring their structural integrity requires careful techniques to preserve their aesthetic and historical value. Here are the most effective methods for repairing cracked porcelain sculptures:

1. Epoxy Resin Adhesives: Use clear, high-strength epoxy resins designed for ceramics. These adhesives bond strongly while remaining nearly invisible when applied correctly.

2. Japanese Kintsugi Technique: This traditional method uses urushi lacquer mixed with gold, silver, or platinum powder to highlight cracks artistically while reinforcing the structure.

3. Micro-Crack Filling: For hairline fractures, apply thin cyanoacrylate (super glue) or specialized porcelain fillers that penetrate deep into the cracks.

4. Professional Conservation Services: For valuable or antique pieces, consult a professional conservator who can use museum-grade materials and reversible techniques.

5. Preventive Measures: After repair, avoid extreme temperature changes and humidity fluctuations to prevent future cracking.

Always test adhesives on inconspicuous areas first and allow proper curing time. Proper restoration not only fixes damage but can also enhance the sculpture's longevity and beauty.