Surgical Guide Types: What Each One Sits On, and What It Needs From You

Clinically reviewed by Jacob Shrayman, DDS, a general dentist who places implants using TrueGuide surgical guides in his own practice.

A surgical guide is named for what it rests on, and what it rests on decides almost everything else about it: how accurately it can be built, what records it needs from you, whether it needs pins, and how much margin the plan has to carry. There are four supports in routine use — teeth, tissue, bone, and a pinned base that everything else stacks onto — and a second, separate choice on top of that: how much of the drill sequence runs through the guide.

This is the reference we work from at TrueGuide. It is written from the laboratory side: what each guide is, what we need to build it, where it loses accuracy, and what you get back. Which one your patient should have is a clinical decision, and it stays yours.

The Four Supports

Tooth-Supported

When to use: stable remaining teeth on one or both sides of the site. Partially edentulous cases, single units through short spans.

The guide seats on the occlusal and axial surfaces of the remaining teeth. It is the most accurate support there is, because a tooth is a hard, repeatable seat that does not compress, and because the same teeth are what the CBCT and the intraoral scan are registered on.

The published numbers put the gap plainly. In a 2026 comparison of support types, tooth-supported guides averaged 0.59 mm at the entry, 0.73 mm at the apex and 1.81 degrees; bone-supported 1.04 mm, 1.61 mm and 2.14 degrees; tissue-supported 1.47 mm, 1.87 mm and 2.95 degrees.

Support has to come from teeth that are staying. If the guide is designed to sit on a tooth you are extracting at the same visit, the plan has a sequencing problem, so tell us which tooth is coming out before we design. A short guide spanning two solid neighbors often seats more definitively than a full-arch one, because a long span accumulates more distortion from the scan.

Pins are usually unnecessary when there is sound support on both sides of the site. On a distal extension, one distal pin.

Tissue-Supported

When to use: edentulous or long-span cases where you are not raising a flap.

The guide seats on mucosa. It is the least accurate of the supports for one mechanical reason: mucosa compresses, and how far it compresses depends on how hard the guide is pressed and on the thickness of the tissue under it.

That is why a tissue-supported guide is planned with fixation pins — also called anchor pins — and a wider safety margin. Pins improve angular and depth accuracy. In the comparison above, both edentulous groups used three to four pins and still deviated more than tooth-supported cases, so pins reduce micro-movement rather than remove it. The effect is also not uniform: in a partial-arch model bilateral pins cut angular deviation from 3.65 to 1.88 degrees, while in a complete-arch comparison a pinned two-guide system came out less accurate than a plain mucosa-supported guide. Pins are not automatically more accurate in a full arch.

It also changes what we need from you. An intraoral scan of a bare edentulous ridge is the least reliable input in digital implant planning, so an edentulous tissue-supported case is planned from a dual scan with a well-fitting denture, or from a pinned workflow. A denture that rocks has to be hard relined first — no soft liner, no metal, no mesh — because a loose denture produces a guide that does not seat.

Bone-Supported

When to use: full-arch cases where a flap is being raised anyway, for extractions or alveoloplasty.

The guide seats directly on the alveolar ridge, which takes the tissue out of the equation. The cost is reflection: the flap has to be raised far enough for the guide to seat fully, and that is a real cost if you were not opening for another reason.

If you are not opening, a pinned tissue-supported guide is usually the better trade.

Stackable, for Full-Arch

When to use: full-arch immediate cases with alveoloplasty and a provisional to deliver.

A stackable system is a different architecture rather than a different support. One base — the foundation guide, or fixation base — is seated and pinned first, and every component after it indexes back to that same base: the bone reduction guide, the osteotomy guide, and the carrier that holds the provisional.

The reason it exists is reference. The moment you reduce bone under a conventional full-arch guide, the surface the guide was seated on no longer exists, and the reference is gone. On a stack, the pinned base survives the reduction, so the osteotomy guide and the carrier are still indexed to the planned position.

A stackable base can itself be tooth-, tissue- or bone-supported, depending on what is in the arch at the start. Tilted implants are routine on a stack; the limits are pin and sleeve access at a steep angle and whether your kit's drills reach.

Stackable systems have their own article: how the stack indexes, what each component does, and what the accuracy data actually shows.

Restorative Space, and How Much Bone Comes Off

Bone reduction is planned from the space the restoration needs, and that space is measured from the implant platform to the opposing occlusal plane — not from the ridge crest. The published minima are about 15 mm for a screw-retained acrylic-titanium hybrid, about 11 mm for a splinted bar overdenture, and about 7 mm for an unsplinted Locator-style overdenture. Those figures come from a published hierarchy of restorative space; it does not give a separate number for a monolithic zirconia full arch, so we do not quote one.

We plan the reduction to the restoration and show it to you on the plan. If the case is short of the minimum, that is what alveoloplasty is for. How much bone comes off a particular patient is your call at the plan review.

How Much of the Drill Sequence Runs Through the Guide

This is a separate decision from the support, and it can be made site by site in the same arch.

A pilot guide controls the first drill only — the entry point and the angle — and you finish freehand. It runs on the drills you already own, which is why it is the route when you do not have a guided kit. An older name for the same thing is a surgical stent.

Drill-guided means the osteotomy sequence runs through the guide and the implant is placed freehand. It is the middle option when you have the drills but not the guided mount.

Fully guided runs the whole drill sequence through the sleeve and seats the implant through it as well. It needs your implant system's guided kit.

A 2025 network meta-analysis puts the difference in plain numbers. Mean angular deviation: 7.46 degrees freehand, 5.94 degrees pilot-guided, 3.67 degrees with dynamic navigation, 2.57 degrees fully guided. At the entry point: 1.56 mm freehand against 0.72 mm fully guided. At the apex: 2.22 mm against 0.88 mm. Two things are worth reading off that. A pilot guide is a real improvement over freehand rather than a token one. And dynamic navigation, for all the equipment behind it, lands between pilot-guided and fully guided static, not ahead of it.

Sleeves, Kits and the Space the Guide Needs

The sleeve is the part of the guide that talks to your drills, and it is kit-specific. Tell us the implant system, the platform and the guided kit by name on the Rx. If a guide is built for a kit you do not own, the depths printed on the drill report are wrong.

We fit the original sleeves from the manufacturer of your guided kit, not generic ones, or we build the guide sleeveless if that is how you work. Sleeveless designs place accurately and irrigate better, which lowers bone temperature during drilling; the trade-off is resin wear at the guide cylinder, so irrigate copiously and debride the osteotomy before placement. Sleeved guides are not particle-free either — metal shedding where drills contact metal sleeves is documented. Your call, noted on the Rx.

The word offset does two jobs and it is worth separating them. Vertical offset — written H2, H4, H6 — is the distance from the top of the sleeve down to where the implant shoulder lands, in millimeters, chosen with your drill length so the stop bottoms out at the planned depth. Intaglio relief is the clearance we build between the guide and the teeth so it can seat at all; ITI guidance puts that at 0.1 to 0.15 mm. They are different numbers and they solve different problems.

Horizontal space: in most systems the master sleeve alone is at least 5 mm in outer diameter, and the guide needs a wall on each side of it, so the mesiodistal gap has to be more than 5 mm. The figure is kit-dependent, so send us the kit name and the site and we will check it against your system before we design.

Vertical access is the constraint that stops more guided molar cases than anything else, and the published measurements are sobering. Mean available mouth opening at the site is about 46 mm at incisor sites, 37 mm at premolar sites and 31 mm at molar sites. The opening a fully guided drill-and-key stack requires is set by your implant system, not by us, and in patients over 55 the requirement at molar sites goes unmet in a substantial share of cases depending on the kit. Measure the opening at the planned site and send it with the case.

When the access is tight there are four things we can change before it prints, and none of them require you to abandon the guide in the chair: shorten the vertical offset, specify a shorter guided drill, move to an open-side sleeve or a keyless kit, or build that one site pilot-only and leave the rest fully guided.

Pins and Seating Verification Windows

Fixation pins are planned where there is bone to take them and where they are clear of the osteotomies — palatal in the upper arch, and between the foramina on the buccal in the lower. They are standard on tissue-supported and edentulous guides, and usually unnecessary on a tooth-supported guide with support on both sides. The pin positions come to you on the plan before anything prints.

Seating verification windows — also called inspection windows — are cut so you can confirm the guide is down: you look through and check for contact with tooth or ridge on both sides, and they let you see irrigation returning. We cut enough to check and no more, because every window takes strength out of the guide.

Guides are built at 3 to 3.5 mm, thicker across a long span. Thinner flexes; thicker eats interocclusal space you may not have. The one place we will not thin the wall is around the sleeve cylinder in a tight mesiodistal site, because that is where a guide fractures.

What the Accuracy Numbers Actually Say

The reference clinical dataset is the 2018 ITI systematic review and meta-analysis of 2,238 implants in 471 patients: static guided surgery averaged 1.2 mm of deviation at the entry point, 1.4 mm at the apex and 3.5 degrees of angulation.

The means are not the useful part. The same review reports much larger outliers — up to 7.8 mm at the entry and 8.7 mm at the apex — in fully edentulous maxillae. Those are not figures for a routine partially edentulous case, and they are the reason a full-arch case is planned differently from a single unit. The 2 mm margin to the inferior alveolar nerve exists for the same reason, and it is what we plan to, along with 3 mm between adjacent implant platforms, 1.5 mm to an adjacent tooth root, and at least 1 mm of buccal bone, 2 mm in the esthetic zone. The 3 mm inter-implant figure is Tarnow's: below it, inter-implant crestal bone loss roughly doubles.

A guide is a very good aiming device. It is not a zero-tolerance jig.

The deviation comes from four places, and they add up rather than cancel out: registration of the CBCT to the intraoral scan, the seat of the guide and any rocking, the mechanical play between drill, key and sleeve, and the free distance between the bottom of the sleeve and the bone. Tissue support adds a fifth, which is compression.

Registration is the one you control at the chair. Registering onto teeth with a direct digital impression is close to exact, on the order of 0.01 mm. Registering onto palatal soft tissue runs around 0.5 mm in a dentate jaw and about 0.16 mm in an edentulous one, with worse outliers. That is why we register on teeth wherever teeth exist, and why a dual scan with markers exists for edentulous cases instead of aligning on soft tissue.

One more figure, because it decides whether you try the guide in beforehand. An ITI clinical review, drawing on two small prospective series, notes that roughly 85% of guides seat with good adaptation and stability and that up to half may need some adjustment before use. That is a small evidence base, not a systematic review, and other series report every guide fitting without adjustment. Either way it is the argument for a five-minute try-in at a consult visit rather than finding out on surgery day.

What Each Type Needs From Your Records

Every guide needs a CBCT in DICOM covering the surgical arch and the anatomy that constrains it, an intraoral scan in STL, PLY or OBJ, a bite, and an Rx. An impression or a stone model works instead of the scan; we digitize it here. What changes by type is what goes on top of that.

Tooth-supported: scan the teeth the guide will sit on, clean and dry, and re-scan if anything about them changes afterward. A temporary replaced or a tooth restored between the scan and surgery day is the single most common reason a guide does not seat.

Tissue-supported and edentulous: retracted photographs, and either a dual scan with a well-fitting denture or a pinned workflow. Dual-scan markers go six to eight around the arch, at least two per sextant, below the CEJ line, spread unevenly, off the occlusal surface, off the borders and off the intaglio, and they must not move between the two scans.

Bone-supported: the same records, plus a clear note on the Rx that a flap is being raised, because that changes the support surface we design to.

Stackable: everything above, plus the opposing arch, the bite, retracted photographs, and what you intend to put on top. A full-arch plan built without the restoration produces implants in acceptable bone and unacceptable teeth.

If there are implants already in the arch that the plan has to reference, seat a scan body on each and write the system and platform on the Rx. Without scan bodies their position is being read off the CBCT, and that is not good enough to build to.

Fit, and What Happens Before It Ships

Every guide is seated on a physical model here before it ships. If you send an impression or a stone model, we fit it on that. If you send a scan, we print the model and fit it on that. Nothing leaves without having been on a model.

Be clear about what that proves and what it does not. A model check proves the guide matches the record it was built from. It does not prove the guide fits the patient, because nothing done in a laboratory can prove that. If the mouth changed after the scan, the guide will match the record and still not seat. The fit of any guide is only as good as the records it was built from, and that is true of every laboratory, including this one.

If a guide does not seat, the rule is whose data caused it. If it is our work — design, printing, warping, sleeve placement — we remake it at no charge and overnight it to you at our cost. If the records we accepted caused it, the remake is half price. If we flagged the records and the case was built anyway, or the mouth changed after the scan, it is a new case at full price.

Three checks tell you it is down: a positive stop when you seat it dry, no rock under finger pressure at either end, and contact visible through the seating verification windows on both sides. On an edentulous case, confirm against the bite index. A guide you are holding in place is a freehand case with a false sense of security, so if it rocks, stop.

Surfaces that carry the seat and the sleeve housing are never adjusted chairside. Once the seating surface is relieved, the plan it was built from no longer applies.

Material, Sterilization and Storage

Guides are printed in Keystone KeyPrint KeyGuide, a light-curing resin for intraoral guided implant surgery, biocompatibility tested to ISO 10993-5 for cytotoxicity and ISO 10993-10 for irritation and sensitization, on Ackuretta printers. It is clear, so you can see the seat through it.

In the United States a patient-specific dental implant surgical guide is regulated by the FDA as a Class II device under 21 CFR 872.4120. We manufacture each one as a single-use custom device from a cleared planning workflow.

Guides ship cleaned and disinfected, not sterile. Run one steam autoclave cycle in a pouch before surgery, on the cycle printed on the insert sheet. Measured dimensional change after a single cycle is small — under about 0.1 mm in published testing, with 121 °C gentler than 134 °C. We supply one guide per case and do not recommend re-sterilizing and reusing it.

Use the guide within about two weeks where you can. Printed guide resins drift slightly in storage — measured change at one month is small but real — and light exposure accelerates it. Keep it in its sealed pouch, cool, dry and out of direct light. Past a month we recommend a try-in on the model before surgery, and if the fit has moved we reprint it.

On milled against printed: one systematic review found milled guides more accurate in vivo than printed ones. The difference is small next to what the records contribute, and printing is what lets a standard guide ship 48 hours after you approve the plan. We print, and we say so.

What We Do Not Decide

Our technicians plan from the CBCT and flag anatomy near the surgical site. The full radiographic interpretation stays with you. Whether this patient is a candidate, whether to raise a flap, whether to load, and where an implant finally goes are clinical decisions, and the plan comes back to you for exactly that reason. Revisions are unlimited and cost nothing until the guide prints, and nothing prints without your approval.

Once you approve the plan, a standard guide ships in 48 hours. Stackable and other multi-layer guides depend on the guide design and the material, and the schedule is set with you at the plan review.

Common Questions

Which guide type is the most accurate?

Tooth-supported, every time. In published comparison it runs about 0.59 mm at the entry and 1.81 degrees, against 1.04 mm and 2.14 degrees bone-supported and 1.47 mm and 2.95 degrees tissue-supported.

When do I actually need a bone-supported guide?

Full-arch work where you are already raising a flap for extractions or alveoloplasty. If you are not opening, a pinned tissue-supported guide is the better trade.

Can a stackable guide be tooth-, bone- or tissue-supported?

Yes. The base takes whatever support the arch offers at the start of the case, and the stack above it indexes to the base either way.

Pilot guide or fully guided?

A pilot guide controls the first drill and you finish freehand, and it runs on the drills you already own. Fully guided runs the whole sequence through the sleeve and seats the implant through it, and it needs your system's guided kit.

Is a pilot guide good enough?

It depends on the site. A pilot guide cuts mean angular deviation from about 7.46 degrees freehand to about 5.94, which is real. Where you are tight to the nerve or the sinus, pilot alone is not the right tool.

What is drill-guided?

The osteotomy sequence runs through the guide and the implant is placed freehand. It is the option when you have the drills but not the guided mount.

What is a surgical stent?

An older name for a pilot guide.

Is dynamic navigation more accurate than a guide?

No. In the 2025 pooled data dynamic navigation runs about 3.67 degrees, between pilot-guided at 5.94 and fully guided static at 2.57.

Do I need a bone reduction guide?

If you are going to a fixed hybrid and need restorative space, yes. Without one the reduction is estimated, and where that shows up is conversion, with the space short.

How much restorative space does a full-arch case need?

Measured from the implant platform to the opposing occlusal plane: about 15 mm for a screw-retained acrylic-titanium hybrid, about 11 mm for a splinted bar overdenture, about 7 mm for an unsplinted Locator-style overdenture. The source does not publish a separate figure for a monolithic zirconia full arch.

Do I need fixation pins?

On tissue-supported and edentulous guides, yes. On a tooth-supported guide with support on both sides, usually not. On a distal extension, one distal pin.

Where do the pins go?

Where there is bone to take them and where they are clear of the osteotomies — palatal in the upper arch, between the foramina on the buccal in the lower. The positions are on the plan before anything prints.

Do pins make a tissue-supported guide as accurate as a tooth-supported one?

No. Pins improve angular and depth accuracy, but edentulous cases with three to four pins still deviate more than tooth-supported cases.

Sleeved or sleeveless?

Your call, noted on the Rx. We fit original sleeves from your kit's manufacturer, or we build sleeveless. Sleeveless irrigates better and runs cooler; the trade-off is resin wear at the cylinder, so irrigate copiously and debride before placement.

Whose sleeves do you use?

The original ones from the manufacturer of your guided kit. Not generic.

What does H4 mean?

Vertical offset — the distance from the top of the sleeve to where the implant shoulder lands. H2 is 2 mm, H4 is 4 mm, H6 is 6 mm, chosen with your drill length so the stop bottoms out at the planned depth. It is a different number from the intaglio relief that lets the guide seat, which runs 0.1 to 0.15 mm.

How much mesiodistal room does a fully guided sleeve need?

More than 5 mm. In most systems the master sleeve alone is at least 5 mm in outer diameter and the guide needs a wall either side of it. The exact figure is kit-dependent, so send the kit name and we will check it.

Will I have room for a guided drill on a lower second molar?

Often not. Mean available opening at molar sites is about 31 mm, against about 37 mm at premolar sites and 46 mm at incisor sites, and the requirement is set by your kit. In patients over 55 molar sites fail the requirement in a substantial share of cases. Measure it and send it with the case.

The access is tight in the back. What are my options?

Four, all of them before it prints: a shorter vertical offset, a shorter guided drill, an open-side sleeve or keyless kit, or pilot-only on that one site with the rest fully guided.

Do you support my implant system?

All of them. Cases already published on our Case Studies page were planned for Nobel Biocare, Straumann, Zimmer Biomet, Implant Direct and Glidewell. Note the system and platform on your Rx and the guide is built to it.

I do not own a guided kit.

Two routes. We build a pilot guide that runs on the drills you have, or we call your implant company and arrange a loaner kit for the case, which most of them do. We do not keep loaner kits — there are too many systems — and you should not buy a second implant system to get one.

How accurate is a guide, really?

Pooled clinical figures for static guides are about 1.2 mm at the entry, 1.4 mm at the apex and 3.5 degrees. Those are means. The large outliers in the same data come from fully edentulous maxillae. Plan the margin against the tail, not the mean.

How accurate are your guides?

A guide reproduces your records. A clean CBCT and a clean scan produce a guide that seats tightly; a poor scan is inherited by the guide. That is the honest answer from any laboratory, and it is why a technician checks the merge before planning starts.

Where does the deviation come from?

Four places: CBCT-to-scan registration, the seat and any rocking, the play between drill, key and sleeve, and the free distance below the sleeve. Tissue support adds compression as a fifth.

Is a full-arch guide as accurate as a single-tooth guide?

No. Edentulous cases run larger deviations than partial ones, which is why full-arch work gets pins, a base and wider margins.

Does a longer guide seat better?

Not necessarily. A short guide over two solid neighbors can seat more definitively than a full-arch one, because the long span accumulates more distortion from the scan.

What safety margins do you plan to?

2 mm from the inferior alveolar nerve, 3 mm between adjacent implant platforms, 1.5 mm to an adjacent tooth root, and at least 1 mm of buccal bone — 2 mm in the esthetic zone.

How do I know the guide is fully seated?

A positive stop when seated dry, no rock under finger pressure at either end, and contact through the seating verification windows on both sides. On an edentulous case, confirm against the bite index.

It rocks on the distal. Can I hold it?

No. A guide being held is a freehand case with a false sense of security. Find the interference, or go freehand on purpose.

The guide will not seat. What happened?

Most often the mouth changed after the scan — a temporary replaced, a tooth restored, tissue swollen. Second most often, an undercut or a tight contact binding it. Check the windows, and do not drill through a guide that is not seated.

Can I adjust it chairside?

A tissue undercut or a tight contact on a surface that does not carry the seat, lightly, yes. Never the seating surfaces and never the sleeve housing.

Should I try it in before surgery day?

Yes. Five minutes at a consult visit turns a surgery-day problem into a scheduling change.

What is the fallback if the guide cannot be used?

Have one before you start. The plan and the drill report give you the positions and depths whether or not the guide is in the mouth, and your regular drills should be open on the tray.

What is the guide printed in?

Keystone KeyPrint KeyGuide, a light-curing resin for intraoral guided implant surgery, tested to ISO 10993-5 and ISO 10993-10, printed on Ackuretta printers.

Is a surgical guide a regulated device?

Yes. In the United States a patient-specific dental implant surgical guide is an FDA Class II device under 21 CFR 872.4120. Each one we make is a single-use custom device.

Do guides arrive sterile?

No. They ship cleaned and disinfected. Run one steam cycle in a pouch before surgery, on the cycle printed on the insert sheet.

Can I autoclave it twice?

We supply one guide per case and do not recommend re-sterilizing and reusing it. A single cycle changes dimensions by under about 0.1 mm in published testing, and 121 °C is gentler than 134 °C.

How long can a guide sit before surgery?

Use it within about two weeks. Resins drift slightly in storage and light accelerates it, so keep it pouched, cool and dark. Past a month, try it on the model first.

Can I reuse a guide on another patient?

No. It is patient-specific and single use.

Milled or printed?

We print. One systematic review found milled guides more accurate in vivo than printed; the difference is small next to what the records contribute, and printing is what holds the 48-hour ship after approval.

What happens if the guide does not seat and it was your mistake?

We remake it at no charge and overnight it to you at our cost. If the records we accepted caused it, the remake is half price. If we flagged the records and the case was built anyway, or the mouth changed after the scan, it is a new case.

Who decides which guide my case gets?

You do, at the plan review. We tell you what each option needs and what it gives up, and we build what you approve. Revisions are unlimited until it prints.

How fast is it?

A standard guide ships 48 hours after you approve the plan. Stackable and other multi-layer guides depend on the design and the material, and the date is set with you at the plan review.

Send a Case

Upload your CBCT, intraoral scan, bite and Rx on the Submit a Case page, or call (201) 255-4233 and we will tell you which guide the case needs before you take another record.

References

Tahmaseb A, Wu V, Wismeijer D, Coucke W, Evans C. The accuracy of static computer-aided implant surgery: a systematic review and meta-analysis. Clin Oral Implants Res. 2018;29(Suppl 16):416-435.

Werny JG, Frank K, Fan S, Sagheb K, Al-Nawas B, Narh CT, Schiegnitz E. Accuracy of implant placement techniques: a network meta-analysis. Int J Implant Dent. 2025;11:35.

Smojver I, Bjelica R, Vuletic M, et al. Accuracy of static computer-assisted implant surgery by guide support type. J Funct Biomater. 2026;17(4):194.

Gargallo-Albiol J, Ortega-Martinez J, Salomo-Coll O, et al. Vertical mouth opening and fully guided implant surgery. Int J Oral Maxillofac Surg. 2024;53(6):526-532.

Carpentieri J, Greenstein G, Cavallaro J. Hierarchy of restorative space necessary for different types of dental implant prostheses. J Am Dent Assoc. 2019;150(8):695-706.

Tarnow DP, Cho SC, Wallace SS. The effect of inter-implant distance on the height of inter-implant bone crest. J Periodontol. 2000;71(4):546-549.

Deferm JT, Nijsink J, Baan F, et al. Soft tissue-based registration accuracy. Int J Oral Maxillofac Surg. 2022;51(2):263-268.