A dental crown, bridge, denture, or implant restoration may look like a small finished product, but several checks can take place before it reaches a dental clinic. Quality control in a dental laboratory involves checking the work at different stages and making sure the laboratory follows the dentist’s prescription.
The process can involve physical models, digital scans, computer-aided design, manufacturing equipment, and trained dental technicians. The exact steps depend on the type of restoration being made.
Quality control is one part of a wider dental treatment process. The dentist remains responsible for assessing the restoration in the patient’s mouth and deciding whether it is suitable for placement.
Why Is Quality Control Important in Dental Laboratories?
Dental restorations need to meet the requirements provided by the dentist. A laboratory may check the information it receives, the materials being used, the design, the manufacturing process, and the finished restoration.
For someone researching dental lab nz, understanding these checks can explain why a restoration may go through several stages before it is sent back to the dental clinic.
Quality-control procedures are used to check for potential issues such as an unclear impression, missing scan information, an incorrect shade record, or a design that needs review. Finding an issue during laboratory production may allow the dentist and technician to discuss it before the restoration reaches the patient.
Quality control does not mean that every restoration will be perfect or that problems can never occur. It is a process used to check work and identify potential issues where possible.
Step 1: Checking the Dentist’s Prescription and Records
The first step is often reviewing the information supplied by the dental clinic.
The dentist’s prescription may include details about the type of restoration, the tooth or area being treated, the material requested and other clinical instructions.
The laboratory may also receive:
- Physical impressions.
- Digital scans.
- Photographs.
- Shade information.
- Bite records.
- Information about existing restorations.
- Implant-related information where relevant.
The technician reviews the information to check whether the laboratory has what it needs to begin the case.
If something is missing or unclear, the laboratory may contact the dental clinic for clarification rather than making assumptions.
Why Clear Instructions Matter
A dental technician works from the information supplied by the dental professional. Clear records can help the technician understand the requirements of the case.
The laboratory should not independently diagnose the patient or change the dentist’s treatment plan without appropriate communication.
Step 2: Inspecting Impressions and Digital Scans
The next step may involve checking the physical impression or digital scan.
Physical Impression Checks
A physical impression needs to capture the required teeth and surrounding areas clearly.
The technician may check for problems such as:
- Air bubbles.
- Tears.
- Distortion.
- Missing areas.
- Poorly recorded margins.
- Other defects that could affect the working model.
If an impression does not provide enough information, the laboratory may contact the dental clinic.
Digital Scan Checks
Digital scans can also contain missing or unclear information.
The technician may review the digital model to check that the required teeth, margins and surrounding areas have been captured.
A digital workflow can reduce the need to physically transport impressions, but it still depends on the quality of the scan and the information recorded.
Step 3: Checking Materials Before Production
Different dental restorations use different materials. The laboratory needs to use the material specified in the prescription and follow the relevant requirements for the workflow.
Materials may include ceramics, zirconia, acrylics, metals, and other dental materials.
Material Records and Instructions
Laboratories should follow the relevant instructions for the materials and equipment they use.
This can include checking product information, processing requirements, and storage conditions where applicable.
Material identification and records can also support traceability. If a question later arises about a particular case or material, appropriate records can help the laboratory and dental clinic review what was used.
Step 4: Reviewing the Digital Design or Working Model
Before a restoration is manufactured, the laboratory may create a physical working model or a digital design.
The technician can review the proposed restoration against the available records and prescription.
Checking the Design
Depending on the restoration, the technician may review:
- Tooth shape.
- Dimensions.
- Margins.
- Contact points.
- Bite relationships.
- Space available for the restoration.
- Connection areas for implant restorations.
The checks performed can vary depending on the type of restoration and the laboratory workflow.
A crown, denture and implant restoration have different requirements, so they do not all go through the same design process.
Digital Design Review
Computer-aided design can allow technicians to view the restoration from different angles before production.
Digital tools can assist with planning and manufacturing, but professional judgement remains important. Software does not replace the dentist’s clinical assessment.
Step 5: Monitoring the Manufacturing Process
Once the design has been reviewed, the restoration can move into production.
The manufacturing method depends on the restoration and material. Some restorations may be milled from a material block, while others may involve printing, casting, pressing or a combination of techniques.
Equipment Checks
Laboratories using digital manufacturing equipment need to follow the equipment manufacturer’s instructions and appropriate maintenance procedures.
This may include checking equipment settings, calibration or other operating requirements.
The exact process depends on the equipment being used.
Production Records
Keeping suitable production records can help the laboratory track work through different stages.
Records may include case information, material details, production steps and any changes made during the process.
Documentation can provide information for reviewing a case if the dental clinic has a question about the finished restoration.
Step 6: Inspecting the Finished Restoration
Once the restoration has been produced, the laboratory can carry out a final inspection.
The checks depend on the type of restoration.
A technician may review:
- Overall shape.
- Dimensions.
- Surface finish.
- Contact points.
- Occlusion.
- Shade where relevant.
- Fit on the working model.
- Signs of damage or defects.
Checking the Fit
The restoration may be checked on the working model where appropriate.
This provides useful information, but it does not replace checking the restoration in the patient’s mouth. The dentist needs to assess the actual clinical fit before placement.
Checking Appearance
For visible restorations, the technician may check the shade and general appearance against the information supplied by the dentist.
Lighting can affect how color appears, so shade assessment may involve specific procedures or records depending on the laboratory and case.
Step 7: Final Review and Documentation
Before the restoration leaves the laboratory, the technician may carry out a final review of the completed work.
This can involve checking that the restoration corresponds with the prescription and that required laboratory stages have been completed.
The laboratory may also record relevant information about the materials and production process.
Why Documentation Matters
Documentation can provide information about how a case was processed.
If the dentist identifies an issue during the clinical fitting, the laboratory can refer back to the available records when discussing the case with the dental team.
Step 8: Communication With the Dental Clinic
Quality control does not stop when the restoration is sent to the dental clinic.
The dentist performs the clinical assessment and may identify something that requires attention. For example, the dentist may decide that an adjustment is needed before the restoration is placed.
The laboratory can then review the dentist’s feedback and make changes where appropriate.
Feedback and Corrections
Good communication helps both sides understand what needs to be addressed.
The dentist can provide clinical information, while the technician can explain laboratory-related details about the restoration.
This does not mean every restoration will require an adjustment. The process varies depending on the case and clinical findings.
The Dentist’s Final Assessment
An important point for patients to understand is that laboratory quality control does not replace the dentist’s examination.
The restoration must be assessed in the patient’s mouth. The dentist considers factors such as fit, bite, surrounding teeth, and the patient’s clinical situation before deciding whether it is suitable for placement.
What Happens If a Problem Is Found?
If an issue is identified during laboratory production, the technician may pause the case and contact the dental clinic.
The dentist may provide additional information, send a new scan or impression, or request a change to the restoration.
If an issue is found during the clinical appointment, the dentist may decide whether an adjustment, remake, or further laboratory work is appropriate.
The response depends on the type of problem and the individual case.
Patients should speak with their dentist if a restoration feels uncomfortable, affects their bite, or does not seem to fit correctly after placement.
How Technology Supports Quality Control
Modern dental laboratories may use digital scanners, computer-aided design software, and manufacturing systems as part of their workflow.
These technologies can help technicians view models, plan restorations, and record case information.
However, technology does not remove the need for trained professionals to review the work. A digital file still needs to contain suitable information, and a manufactured restoration still needs to be assessed.
For clinics and patients working with a dental lab nz, the laboratory’s technology is only one part of the overall process. Clear prescriptions, accurate records, trained technicians and communication with the dental clinic remain important.
Conclusion
Quality control in a dental laboratory involves several stages, from checking the dentist’s prescription and impressions to reviewing the design, monitoring production and inspecting the finished restoration.
The exact checks depend on whether the laboratory is producing a crown, bridge, denture, implant restoration or another dental appliance. Physical and digital workflows may also use different methods.
Laboratory quality control helps identify potential issues during production, but it does not guarantee a particular clinical outcome. The dentist still needs to assess the completed restoration in the patient’s mouth before deciding whether it is suitable for placement.
If you have questions about a dental restoration, ask your dentist how the laboratory contributes to your treatment and what checks are carried out before your restoration is fitted.