Types of Night Guard: Which One Suits Whom

People think of a night guard as a single device, but there are several types made for different purposes. Which is chosen depends on whether the problem lies in the muscles or the joint, and on the degree of wear on the teeth.

What a guard is for

A guard has three functions: separating the teeth to prevent contact wear, distributing chewing force over a wide surface, and providing a position in which the muscles can rest. It does not stop clenching; it limits the consequences.

Knowing this distinction sets the expectation correctly. A patient wearing a guard may still be clenching; what matters is that the wear happens on the guard rather than the teeth.

Hard splints

Hard splints made of acrylic are the type most often chosen for clenching and grinding. The surface is flat and the contact points of the opposing teeth are adjusted precisely; that adjustment determines whether the splint works.

It is durable, lasts many years and does not cause unwanted tooth movement. Adaptation takes a few nights; increased saliva and slight changes in speech in the first days are normal.

Soft guards

Soft guards feel more comfortable and cost less. Their flexibility, however, stimulates the chewing reflex in some patients and can increase clenching. They also wear quickly, and contacts cannot be adjusted as precisely as on a hard splint.

They still have a place: for short-term protection, in sport and in patients with mild symptoms. As a long-term solution they do not replace a hard splint.

Ready-made or custom?

Ready-made guards softened in hot water and bitten into are cheap and immediately available. Because they do not fit exactly, however, they are uncomfortable and can create unbalanced contacts.

A poorly fitting guard concentrates force on particular teeth instead of spreading it, and can over time cause movement or sensitivity in those teeth. A custom guard is made from an impression in the laboratory and adjusted in the surgery; the real difference lies in that adjustment.

Upper or lower jaw?

Either can be used. Upper splints are more common and sit more stably. Lower splints are less bulky, affect speech less and are better tolerated by patients with a strong gag reflex.

The choice follows the patient's tooth arrangement, any prostheses or implants and their own preference. Neither is generally superior; the better guard is the one that fits and is adjusted correctly.

Guards for specific purposes

• Anterior bite plates: to relax muscles, only short-term and monitored
• Repositioning splints: to position the joint in disc displacement
• Soft sports mouthguards: against impact, not for night use
• Snoring appliances: advance the lower jaw, planned with sleep medicine

Each of these serves a different purpose and they are not interchangeable. Confusing a snoring appliance with a night guard is a common error.

Care and lifespan

The guard is cleaned each morning with cold water and a soft brush; toothpaste should not be used, as it is abrasive and scratches the surface. Hot water deforms the acrylic and ruins the fit.

A short soak in a denture cleaning tablet once a week dissolves accumulated deposit. The guard should not be left wet after removal; one kept damp in a closed case quickly develops odour and fungal growth.

It is stored dry in a ventilated case. Hard splints last years with care; soft guards usually need replacing within a year or two. A guard that is perforated, cracked or no longer seating should not continue to be used.

Why guards end up unworn

The commonest reason is fit: if the guard is tight, provokes gagging or increases morning jaw pain, the patient abandons it within a few nights. All of these are adjustable, and a review appointment should come before the guard is discarded.

The second is a misplaced expectation. A guard does not stop the pain on the first night; muscle relief usually appears within two or three weeks. When that timeframe is explained at the outset, the great majority of patients keep using it.