Quick answer: For aggressive chewers, look for puzzle toys made from solid natural rubber or thick plastic with no small detachable parts — raised compartments rather than plastic pegs or sliders.
Thin plastic puzzle boards are destroyed quickly by dogs that chew rather than solve. Natural rubber puzzles (Kong's line, West Paw) are significantly more durable. Look for rubber rated for 'power chewers' — it's thicker and has no hollow sections that crack under bite pressure.
Avoid puzzles with small movable pieces (sliders, pegs, covers) that aggressive chewers will remove and potentially swallow. Lick mats and snuffle mats are a safer alternative for mental stimulation — they engage the dog without any destroyable components.
No puzzle toy is truly indestructible for every dog. Supervise the first few uses and inspect for cracks, chips, or missing pieces after each session. A cracked rubber toy with sharp edges is more dangerous than no toy. Replace any toy showing structural damage.
For genuinely aggressive chewers, frozen stuffed Kongs and snuffle mats often outlast dedicated puzzle boards. Look for 'power chewer' ratings and supervise all new toys initially.