 Few moments are more frustrating than preparing for a straightforward crown fit and discovering that the restoration is high in occlusion, will not pass the contacts or does not match the surrounding teeth. The appointment becomes longer, the patient loses confidence and the practice and laboratory must decide whether the restoration can be adjusted or needs to be remade. These problems are rarely explained by one simple cause. The final crown is the result of a chain involving preparation, tissue management, impressions or scans, bite registration, prescription, design, manufacturing and laboratory quality control. An error or uncertainty at any point can affect the final outcome. The most productive response is not to ask whether the dentist or laboratory is to blame. It is to identify where the information or process changed, correct it and strengthen the shared checkpoints that prevent the same problem happening again. Why a crown can return high
A crown described as high may have one premature contact, excessive contact across much of the occlusal surface or an inaccurate relationship to the opposing dentition. It is important to distinguish these possibilities because they do not all have the same cause. Potential clinical and recording factors include:
Potential laboratory factors include:
The first question should be whether the crown is fully seated. A tight contact, internal interference or marginal obstruction can stop a restoration seating completely and create the appearance of a high occlusion. Adjusting the occlusal surface before confirming complete seating can therefore remove unnecessary material without solving the underlying issue. Check seating before adjusting the bite A logical chairside sequence protects the restoration and helps identify the source of the problem. First, inspect the margins and assess whether the crown reaches its intended position. Then evaluate the proximal contacts. If a contact prevents seating, identify and adjust it conservatively before reassessing the margin and occlusion. Internal fit indicators, magnification and appropriate radiography may be useful according to the clinical circumstances. The exact method will depend on the restoration, preparation and cementation plan. Only once full seating has been confirmed should the occlusion be assessed. This prevents an incomplete seating problem being mistaken for an occlusal design problem. If a restoration requires extensive adjustment, pause and investigate. Repeatedly grinding until the crown fits may conceal the original cause and compromise anatomy, strength or surface finish. Insufficient occlusal reduction limits the laboratory’s options The laboratory requires enough space for the prescribed material and design. When reduction is limited, the technician may face a poor choice between producing a restoration that is too thin and designing a crown that creates excessive occlusal contact. Digital clearance maps are useful, but they do not create physical space. They only reveal what is available. Before scanning or taking the impression, assess clearance in the patient’s intended occlusion. Static clearance alone may be insufficient in a patient with heavy excursions, bruxism or a restrictive opposing cusp. The prescription should also identify factors that materially affect design, including:
If the laboratory identifies inadequate clearance, a discussion before manufacturing is usually more useful than silently compromising the crown. An inaccurate bite record can affect an otherwise accurate crown The working preparation may be captured perfectly while the interarch relationship is wrong. Digital bite records can be affected by limited buccal information, unstable closure, mobile teeth, soft-tissue interference or incorrect alignment by the software. Conventional bite materials can distort, remain incompletely seated or hold the patient away from the intended position. When checking a digital bite, compare the virtual articulation with what was observed clinically. Warning signs include posterior separation, extensive penetration, contact only on one side or an unexpected mandibular shift. For conventional cases, make sure the record is stable, appropriately trimmed and seated without rocking. The opposing impression must also reproduce the antagonist accurately. A distorted opposing alginate impression can alter the occlusion even when the master impression is excellent. Research into digital bite registration continues to show that virtual occlusion must account for clinical variables, including physiological tooth displacement. This is a reminder that an apparently precise digital image still needs clinical interpretation. Clinical research on digital bite registration and virtual occlusion. Why interproximal contacts can be too tight A crown with tight contacts may not seat, may require lengthy chairside adjustment or may make oral hygiene difficult. The contact could be affected by the clinical record, model, design or manufacturing process. Possible causes include:
The technician needs clean, complete information from the teeth beside the preparation. A scan that captures the preparation but leaves soft or incomplete proximal anatomy makes contact design less predictable. The laboratory should inspect the digital model, apply appropriate contact parameters and physically or digitally quality-check the finished crown. However, contact is not a fixed property of the laboratory file alone. Teeth can move, and the clinical situation at fit may not be identical to the record captured previously. Implant cases deserve particular attention because an osseointegrated implant does not respond to load in the same way as a natural tooth with a periodontal ligament. The laboratory should know when the restoration or its antagonist is implant-supported so that the case can be designed and assessed appropriately. Incomplete margins create uncertainty at the most important boundary The finish line determines where the restoration ends. If part of it is obscured by blood, saliva, gingiva, impression drag or incomplete scan data, the technician cannot define the crown margin confidently. Guessing may produce an overextended, underextended or poorly contoured restoration. Rejecting the record may be inconvenient, but it protects the patient and both clinical teams from a more serious problem later. Before sending the case:
The test is simple: if the clinician who prepared the tooth cannot clearly identify the complete margin in the record, the technician working remotely should not be expected to do so. Why a written shade may not be enough A shade such as A2 communicates a useful starting point, but it does not fully describe the appearance of a natural tooth. Teeth vary in value, chroma, translucency, surface texture, incisal characterisation and colour distribution from cervical to incisal. This is especially important for anterior restorations and single central incisors, where small differences are highly visible. Useful shade communication may include:
For complex anterior cases, direct communication with the technician or a laboratory shade assessment may be appropriate. The stump shade matters beneath translucent restorations The underlying preparation can influence the final appearance of a ceramic restoration. A discoloured stump, metal core, implant abutment or unusually bright substrate may show through or alter the perceived value. For relevant anterior and translucent restorations, provide the stump shade after preparation. A photograph with an appropriate stump shade reference can help the technician select opacity, ceramic layering and material strategy. Without this information, the laboratory may design a restoration against a neutral digital model that does not reproduce the optical effect present in the mouth. The prescription should also identify whether the substrate includes metal, composite, a darkened tooth or an implant abutment. This is not an optional aesthetic detail when it changes the material decision. The laboratory prescription is part of the restoration An incomplete prescription forces the laboratory to pause, make assumptions or request clarification. None of these helps the patient’s timeline. The prescription should clearly state:
If information is clinically significant, it should be written down. A technician should not have to infer it from an old case, a brief telephone conversation or the appearance of the scan alone. What is chairside and what is laboratory responsibility? Some factors sit clearly within one part of the workflow, while others are shared. The clinical team is responsible for preparation, tissue management, the accuracy of the impression or scan, jaw records, shade capture, prescription details and the final clinical assessment. The laboratory is responsible for inspecting the records, querying inadequate information, designing within the prescription, selecting the agreed material, controlling manufacturing processes and quality-checking the restoration before dispatch. Shared responsibility includes recognising limited clearance, planning complex occlusion, resolving ambiguous margins, selecting materials for difficult substrates and communicating when the proposed outcome cannot be achieved predictably from the available information. This distinction should guide investigation, not blame. How to investigate a problem fairly When a crown does not fit as expected, preserve the evidence and work through the problem systematically. Record:
The laboratory should review the original records, design, manufacturing data and quality-control findings. If the cause remains uncertain, both teams should agree what new records are needed and how the remake will be managed. A shared pre-manufacture checklist Many crown remakes can be prevented if both teams control the same checkpoints. Before the case leaves the practice, confirm:
Before manufacturing, the laboratory should confirm:
The aim is not to eliminate every complication. It is to stop predictable uncertainty from progressing into manufacture. Better communication reduces repeat work for everyone A successful crown is a shared outcome. The dentist sees the patient, controls the clinical records and evaluates the restoration in the mouth. The technician interprets those records and turns them into a precisely manufactured restoration. When both teams communicate early, inspect their own stage of the process and provide useful evidence when something goes wrong, remakes become easier to prevent and fairer to investigate. That means fewer interrupted clinics, less repeated laboratory work and a more confident experience for the patient. We provide a trusted laboratory service delivering consistent quality, saving chairside time, and supporting predictable patient outcomes. Thank you for reading, are you currently having issues with your lab work? Want to talk to us about it? 📞: 0208 520 8528 📧: [email protected] 📍: 25A St James Street, London, E17 7PJ
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Private Dental Laboratory in London
 Kash Qureshi - Managing Director, Clinical Dental Technician
About the author:
Kash Qureshi is a Clinical Dental Technician (Denturist) in the U.K who oversees and quality controls over 3000+ fixed and removable prosthesis including implant cases from a clinical and technical aspect monthly at Bremadent Dental Laboratory & Swissedent Denture Clinic in London. www.swissedent.co.uk www.bremadent.co.uk [email protected] Categories
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