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Meta Title: Night Guards and Splints Guide: Michigan Splint, NTI, Hard Guard & Dual-Laminate | Flora Orthodontics
Meta Description: Clinical guide to night guard and splint selection for UK dentists. Compare Michigan splints, NTI devices, hard occlusal guards, soft guards, and dual-laminate designs — with lab submission requirements from Flora Orthodontics.
URL Slug: /blog/night-guards-splints-guide
Night Guards and Splints for Dental Practices: Michigan Splints, NTI Devices, Hard Guards and Dual-Laminate Appliances
The term night guard covers a wider range of clinical decisions than most prescription forms suggest. A soft guard for a patient who grinds moderately is not the same appliance as a Michigan splint for a patient with a measured ICP-CR discrepancy. An NTI device for bruxism-related headache management follows different design logic again. When those distinctions collapse into a single “night guard” prescription, the appliance gets fabricated, but it may not serve the purpose for which it was prescribed.
At Flora Orthodontics, we fabricate night guards and splints for dental practices across London and the UK, including soft guards, hard guards, dual-laminate designs, Michigan splints, NTI-style devices, and other clinician-specified occlusal appliances.
The cases that are delivered and fitted without a return visit are not necessarily the simplest ones. They are the ones where the appliance was chosen for a specific reason, that reason was written on the prescription, and the records allowed the laboratory to build to it rather than guess at it.
This guide explains how to think about occlusal appliance selection from a clinical-laboratory perspective: what the main appliance types are designed to do, when each is most appropriate, what information distinguishes a clear prescription from an ambiguous one, and what Flora needs to fabricate predictably.
Night Guard, Bite Splint, Occlusal Splint: Understanding the Terminology
The overlap in terminology creates more confusion in practice than it probably should.
Night guard is the broadest term. It describes any removable appliance worn primarily at night, typically to reduce the effects of bruxism or clenching. It does not specify material, design, coverage, or occlusal intent.
Bite splint and occlusal splint are often used more precisely. They usually imply some degree of deliberate occlusal design, controlled contact pattern, specific vertical dimension, or a therapeutic positioning objective, rather than simple protective coverage.
Dental splint is another umbrella term used across patient-facing and clinical contexts. When patients search for “dental splint” or “dental splint types,” they are often looking for an explanation of exactly the distinctions this guide covers.
In practice, the terminology matters less than the clarity of the design brief. What matters clinically is whether the appliance is primarily protective, primarily deprogramming-oriented, primarily position-based, or some combination of these, and whether that intent is written in a way the laboratory can act on.
Occlusal Appliances Compared
| Appliance | Design Logic | Primary Indication | Clinical Watchouts |
|---|---|---|---|
| Soft Night Guard | Vacuum-formed EVA or similar over full arch; no occlusal design intent | Basic protective coverage for mild to moderate parafunction; good patient acceptance | Can increase muscle activity in some bruxism cases; not appropriate for TMD management or controlled occlusal objectives |
| Hard Full-Coverage Guard | Rigid acrylic over full arch; adjustable at delivery; stable occlusal surface | Moderate to heavy bruxism; cases requiring chairside occlusal refinement | Requires delivery adjustment protocol; flat-plane contacts should be verified at fit |
| Dual-Laminate Guard | Soft inner layer for retention and comfort; hard outer surface for durability | Patients who find rigid appliances intolerable but who need more durability than soft-only provides | Not appropriate where occlusal scheme design matters; thickness and coverage must be controlled |
| Michigan Splint | Full-coverage rigid acrylic; flat occlusal platform; bilateral simultaneous contacts; anterior guidance on removal | Occlusal stabilisation, ICP-CR discrepancy management, bruxism with occlusal component | Requires accurate records, reliable bite data, and clear delivery adjustment expectations |
| NTI-Style Device | Anterior only; limits posterior contact; reduces elevator muscle activity by interrupting the jaw-closing reflex | Bruxism-associated headache, masseter hypertrophy, cases where limiting posterior muscle engagement is the primary goal | Not full coverage. Posterior teeth are disoccluded. Patient selection and monitoring matter. Not appropriate for all bruxism cases. |
| Tanner and Other Named Appliances | Clinician-specified design; varies by practitioner training and case objective | Cases where the dentist has a specific treatment rationale tied to a defined appliance design | Must be prescribed explicitly. The lab cannot infer the design from the appliance name alone. |
Choosing the Right Appliance by Indication
When a Soft Guard Is the Right Choice
The soft guard has two clinical strengths: patient acceptance and simplicity. For mild to moderate bruxism where the primary objective is protective coverage without a complex occlusal design requirement, it remains a practical first-line option. Patients who have never worn an appliance before often adapt more easily to a soft design, which reduces the early dropout that makes any night guard prescription less valuable.
The limitations are equally important to understand. Research on soft guards in heavy bruxism suggests that for some patients, the proprioceptive feel of biting into a soft surface can actually increase muscle activity rather than reduce it. For moderate to severe bruxers, or for any case with a therapeutic occlusal objective, a soft guard is unlikely to be the best long-term prescription.
For the laboratory, soft guard prescriptions are typically straightforward: full arch, upper or lower, vacuum-formed. The most useful additional information is any history of previous appliance fracture, which would indicate a thicker or harder design is needed, and whether the case is upper or lower arch.
Hard Full-Coverage Night Guard
The hard guard offers what the soft guard cannot: a stable, adjustable occlusal surface. Because the material is rigid, it allows the dentist to refine contacts at delivery using articulation paper, selective grinding, and standard occlusal adjustment protocol. This is the design most appropriate for moderate to heavy bruxism where durability and chairside refinement are both part of the clinical workflow.
From the laboratory side, hard guard cases benefit from specific design instructions:
- upper or lower arch
- full coverage or coverage to a defined extent
- thickness specification where you have a preference, typically 2 to 3 mm for full-arch hard guards
- whether a flat-plane contact scheme is required, or whether the occlusal surface should be fabricated to the opposing arch anatomy
The delivery protocol matters as much as the fabrication. A hard guard that seats without adjustment is unusual. Plan for selective equilibration at fit.
Dual-Laminate Night Guard
The dual-laminate design attempts to solve the tolerance versus durability problem. A softer inner surface improves retention and comfort. A harder outer surface resists the wear and compression that pure soft guards experience quickly in active bruxers.
It is a practical compromise for patients who refuse rigid appliances but who need more longevity than a soft guard provides. The watchout is that the dual-laminate design does not offer the same occlusal control as a full hard guard. If the case requires flat-plane contacts or controlled vertical dimension, a hard guard or Michigan splint is the correct choice.
Michigan Splint
The Michigan splint is one of the most recognised occlusal appliance designs precisely because it is not just a hard guard with a specific name. It carries a defined design logic: full coverage of one arch, typically upper, a flat occlusal platform that provides bilateral simultaneous contacts in centric relation, and anterior guidance that disoccludes posterior teeth during lateral and protrusive movements.
That design logic serves a clinical purpose. By providing stable bilateral contacts in CR and removing posterior interference during excursive movements, the Michigan splint can reduce elevator muscle activity and provide a stable reference for the musculoskeletal system. It is commonly used for occlusal stabilisation, ICP-CR discrepancy cases, and bruxism presentations with an identifiable occlusal component.
Because the Michigan splint is design-specific, it requires more from the records than a protective guard:
- accurate full-arch impressions or scans for both arches
- reliable bite registration, ideally in centric relation if the case involves ICP-CR management
- clear notation that a Michigan design is requested rather than a generic hard guard
At delivery, selective adjustment to achieve the design's contact pattern should be expected as part of the clinical workflow, not as an indicator that something went wrong in fabrication.
NTI-Style Devices
The NTI, or Nociceptive Trigeminal Inhibition device, is an anterior-only appliance that limits posterior tooth contact and, by doing so, reduces the intensity of jaw-closing muscle contraction. Unlike full-coverage guards, its therapeutic rationale is based on interrupting the jaw-closing reflex rather than providing a protective surface across all teeth.
Clinical applications include bruxism-associated headache and facial pain, masseter hypertrophy where reducing elevator muscle engagement is the primary objective, and selected cases where the dentist has determined that reducing posterior muscle recruitment is more useful than providing full-coverage protection.
Because the NTI leaves posterior teeth disoccluded, patient selection matters. The device is not appropriate for all bruxism presentations, and regular monitoring is standard practice when it is used. For the laboratory, NTI-style fabrication requires clear identification of the anterior coverage extent, appliance thickness, and any design preferences specific to the prescribing clinician's approach.
Why Records Matter More Than the Appliance Category
Most avoidable night guard failures, appliances that fracture early, do not fit accurately, require excessive adjustment, or produce a patient complaint, trace back to one of three record problems:
Incomplete bite information
For a simple soft guard, full-arch impressions alone are often sufficient. For a Michigan splint or any design where the occlusal contact pattern matters clinically, bite data is not optional. Without a reliable bite registration, the laboratory cannot mount the case accurately and cannot ensure bilateral simultaneous contacts in the intended jaw position.
Unclear appliance specification
“Night guard — upper” is a minimal prescription. The laboratory will produce an appliance, but the design decisions about thickness, material, occlusal scheme, and coverage extent will be made by the technician rather than by the dentist. That is appropriate for simple protective guards but not for any case with a therapeutic objective.
Missing history
Whether the patient has fractured previous appliances, whether they have existing restorations that affect how the appliance seats, or whether they have a known ICP-CR slide, this information changes what gets fabricated. Including it saves a rematch.
| Appliance | Records Required | Digital Submission Notes | Key Lab Notes to Include |
|---|---|---|---|
| Soft or Hard Night Guard | Full-arch working model or scan; opposing arch; bite record where occlusal scheme is relevant | STL accepted; full arch anatomy must be cleanly captured | Upper or lower arch, thickness preference, material, full coverage, any history of fracture |
| Dual-Laminate Guard | Full-arch working model or scan; opposing arch | Digital suitable when occlusal anatomy is well captured | Arch, patient comfort priority, any prior soft guard rejection or fracture history |
| Michigan Splint | Accurate full-arch records for both arches plus bite registration; ideally CR if the case involves ICP-CR management | Digital accepted; bite and articulation data must be reliable for Michigan design to be fabricated correctly | Michigan design explicitly requested; arch; contact scheme if specified; any deprogramming context |
| NTI-Style Device | Full-arch impression or scan; anterior coverage extent | Digital suitable; capture anterior contacts cleanly | Anterior coverage extent, design rationale, any specific thickness or retention preferences |
| Named or Custom Splint | Full records with bite; case-specific instructions | Confirm with lab before submission for non-standard designs | Exact appliance requested, purpose, arch, contact rationale, any special features |
Five Prescription Errors That Create Delivery Problems
Prescribing “night guard” without specifying the design
Soft, hard, dual-laminate, Michigan, and NTI are different appliances for different indications. The lab cannot select the right one from the category label alone.
Omitting bite information for a Michigan or splint case
A Michigan splint built without reliable bite data cannot deliver the bilateral simultaneous contacts that define the design. The appliance may seat well on the model and still require extensive adjustment at delivery because the mounting was inaccurate.
Choosing a soft guard based on assumed patient preference
Patient preference for comfort matters, but the appliance choice should be driven by the clinical indication first. A soft guard in a heavy bruxer may be comfortable for one night and fractured by the third.
Not distinguishing Michigan splints from generic hard guards
A request for “a hard upper guard, like a Michigan” will produce either a Michigan or a generic hard guard depending on how the lab interprets it. If you want a Michigan, prescribe a Michigan.
Skipping the delivery adjustment protocol
Occlusal appliances, particularly Michigan splints and hard guards, are fabricated to a model and a mounting. The patient's mouth is not identical to the model, and adjustment at delivery is a standard part of the process, not an indication that fabrication failed.
Complete Submission to Flora Orthodontics
A complete night guard or splint submission should include:
- exact appliance type, not just “night guard”
- upper or lower arch
- full-arch working model or STL
- opposing arch model or scan
- bite registration where the appliance design requires it
- material preference if specified: hard, soft, dual-laminate, acrylic
- thickness preference if important
- occlusal design notes for Michigan or other named splints
- any history of previous appliance fracture, intolerance, or replacement
- delivery timing requirements
Submit a Night Guard or Splint Case to Flora Orthodontics
Clear prescriptions produce fewer remakes, fewer delivery issues, and fewer assumptions at the laboratory stage. Send complete records, specify the appliance design, and give the lab the context needed to fabricate predictably.
Submit Your CaseFrequently Asked Questions
What is the difference between a night guard and a Michigan splint?
A night guard is a broad term for any removable appliance worn at night for protection. A Michigan splint is a specifically designed full-coverage occlusal appliance with a flat platform, bilateral simultaneous contacts in centric relation, and anterior guidance that disoccludes posterior teeth on excursion. The Michigan design is not simply a hard guard with a different name. It carries a defined occlusal logic that requires accurate records and delivery adjustment to deliver correctly.
What is an NTI dental night guard?
An NTI, or Nociceptive Trigeminal Inhibition device, is an anterior-only appliance that limits posterior tooth contact and reduces jaw-closing muscle intensity. Unlike full-coverage guards, it works by interrupting the jaw-closing reflex rather than protecting all teeth. It is commonly used for bruxism-associated headache and masseter hypertrophy, but because posterior teeth are disoccluded, patient selection and regular monitoring are important.
What are the different types of dental splints?
The main types are soft night guards, hard full-coverage guards, dual-laminate guards, Michigan splints, NTI-style anterior devices, and clinician-specific named designs such as Tanner appliances. Each serves a different clinical indication. Soft guards provide comfort and basic protection. Michigan splints provide controlled occlusal stabilisation. NTI devices target muscle reduction through anterior positioning. The right choice depends on the therapeutic objective, not on the category name alone.
When should a dentist choose a hard night guard instead of a soft guard?
A hard guard is generally preferred when durability, occlusal stability, and chairside adjustability are more important than initial softness. It is commonly appropriate for moderate to heavy bruxism, cases where a predictable occlusal contact scheme is needed, or patients with a history of breaking softer appliances. A soft guard may be appropriate as a first step for mild parafunction or where patient tolerance to rigid appliances is a concern.
What are the side effects of a dental night guard?
The most commonly reported issues include initial discomfort during adaptation, excessive salivation in the first few nights, and, in some patients with soft guards, a possible increase in muscle activity caused by the proprioceptive feel of biting into a compliant surface. A poorly adjusted hard guard or Michigan splint can cause occlusal discomfort or bite changes if contacts are not correctly managed at delivery. Proper appliance selection, accurate fabrication, and a thorough delivery appointment reduce these risks significantly.
Do you accept digital scans for night guards and splints?
Yes. Flora accepts digital submissions for most night guard and splint cases, provided the scan captures the full arch clearly and bite or articulation data is adequate for the requested design. Michigan splints and other occlusal design-specific appliances require reliable digital bite capture to mount accurately. A scan without dependable bite data is insufficient for these cases.
Why does a Michigan splint need delivery adjustment?
A Michigan splint is fabricated to a model mounted from a clinical bite record. The final occlusal contact pattern, bilateral simultaneous contacts, anterior guidance, and posterior disocclusion, is refined at the fit appointment using articulation paper and selective adjustment. Delivery adjustment is a planned part of the Michigan splint protocol, not an indicator of a fabrication error. Clinicians who skip this step reduce the effectiveness of the appliance regardless of how well it was made.
Flora Orthodontics is a full-service dental laboratory serving dental practices across London and the UK. We fabricate night guards, splints, orthodontic appliances, and crown and bridge work using clinician-focused communication and digital-compatible workflows.