Choosing a dental laboratory can be fraught with difficulty and confusion. It is easy to be overwhelmed by the large number of options available to clinicians. To evaluate these options and to choose among them, the clinician needs a clear strategy based on relevant criteria. Once a laboratory has been selected, the next and never-ending task is one of effective communication with the technician to ensure ongoing clinical excellence along with the appropriate technical support. One of the greatest challenges of implant dentistry is the mutual and continued transfer of clinical knowledge and information with the dental lab.

After completing this ITI Academy Module, you should be able to identify the criteria for selecting a dental laboratory partner; describe the information needed to prescribe work for a dental technician; and explain the quality assessment processes used in reviewing prostheses provided by a dental lab.

When considering a dental lab, it is important to have a clear understanding of the role that the dental technician plays in the delivery of clinical services. Whilst a technician may not physically be present in the clinic, he or she nevertheless forms a critical part of the implant treatment team. As such, it is beneficial to consider the dental technician as a clinical partner. In the past the expertise and role of technicians in the clinical sphere has all too often been downplayed. However, the delivery of high-quality dental implant treatment is impossible without a successful partnership between clinician and technician, whereby the sharing of information as well as a shared passionate pursuit of clinical excellence results in the best possible outcome for patients.

The location of a dental lab is one factor to consider. Some clinics have the luxury of an on-site or 'intramural' dental technician. This allows for the most direct and convenient access to laboratory services for both clinicians and patients. However, most clinicians will need to utilize an off-site or 'extramural' dental lab. In this case, from a transport and communications perspective, it is generally more effective and convenient to work with a local dental lab that is physically close to the dental clinic. Doing so will reduce the time needed to transport cases to and from the clinic. Using a local lab will also expedite custom shade-matching evaluations with the ceramist as well as other treatment stages such as try-ins. Utilizing a remote lab that is located in another city or state requires closer coordination between clinic and lab to ensure that cases are delivered within agreed schedules, taking into consideration various methods of delivery, such as standard post or express courier services. With a remote dental lab, there is always the risk of parcels being misplaced or failing to meet delivery deadlines, not to mention the difficulty of patient access to custom shade-matching procedures.

It is critical that there is mutual understanding between clinician and technician regarding workflow and time management. Some laboratories take pre-bookings, so when possible, the clinician should inform the dental lab regarding the details of the case to be sent, including the type of prosthesis and expected times for delivery and insertion. Tight coordination is needed for treatment requiring multiple stages, such as try-in of abutments or wax-ups for implant- or tooth-supported prostheses.

Some cases may require the involvement of third parties external to the dental lab, such as milling centers or CAD/CAM facilities. The involvement of such parties requires further interaction between clinician and technician, or with the third party itself. Some CAD/CAM centers require clinicians to verify and approve digital designs prior to proceeding to the next stage. It was a specific recommendation of the 5th ITI Consensus Conference that the clinician should play an active role in controlling all CAD/CAM processes and material selection and should approve the final virtual prosthesis that dictates the abutment or framework design. The clinician also should be aware of what production methods are being used, such as 3D printing of resin models, and whether such work is being outsourced to other facilities. The involvement of third parties may also impact on the time needed for prosthesis fabrication.

The technician should be experienced with the implant systems that the clinician and their surgeon use. In addition, it is important that the technician is familiar with the techniques and materials that the clinician may wish to prescribe, such as certain systems of CAD/CAM manufacture that are specific to the implant system. Whilst CAD/CAM providers may claim to produce components that are compatible with multiple implant systems, such components may differ significantly from the original intended implant design and tolerances. The clinician may also have a preference for certain types of alloys. In this clinical image, a high-gold alloy has been used as the substrate. A related factor to consider is whether it is ideal to partner with a single lab that deals with all aspects of technical work, including fixed and removable prostheses, or whether it is preferable to work with separate labs for different types of prostheses.

Because the fabrication of implant prostheses is largely an art as well as a science, it is important that the clinician and technician maintain a philosophical convergence regarding the artistic design of prostheses. Different technicians made these crowns on the upper right canine. Both crowns satisfy clinical parameters for function and esthetics. However, there are significant stylistic differences between the two prostheses. These differences may not be entirely resolvable as they are largely based on each technician's preferences for form and shade.

The interaction between clinician and technician involves a financial transaction; therefore criteria related to costs play a role in selecting a lab. First, it is important for the clinician to be aware that in most cases the total lab charge will be a sum of different fees, such as prosthesis fabrication, articulation, metal alloys, and cast preparation. The itemized breakdown of these fees may or may not be shown on the final invoice. Second, the amount to be charged for each component of the definitive prosthesis should be presented to the clinician in a straightforward and unambiguous manner. The lab should also be clear as to whether any surcharges are applied to components that it obtains from the implant manufacturer. Finally, the clinician should be mindful that third-party providers such as milling centers will either bill the dental clinic separately or bill the lab, who will then decide whether to add a surcharge before passing on that cost to the clinic.

Ultimately, clinicians should seek to deliver high-quality treatment by utilizing technicians dedicated to producing high-quality prostheses. Laboratories that operate with an emphasis on high production may sacrifice quality. Every clinician should weigh a laboratory's value proposition for his or her patients. In this value proposition, the results - for example, the esthetics, function, and longevity of the prosthesis - and process quality - such as the required number of appointments and time between procedures - are offset by the financial, time, and biological costs. A higher value is derived for patients when the results and process quality increase and the cost decreases. However, a low-cost prosthesis may also be accompanied by poor long-term results. The patient may then incur significantly higher financial, time, and biological costs as the result of a poorly fitting prosthesis or premature failure of materials.

Selection Criteria, Key Learning Points: The dental technician operates as a clinical partner; therefore, clinician and technician should have a shared philosophy regarding prosthetic design. It is important to consider the location of a lab in relation to the clinic and the effect of that distance on the coordination of treatment workflows. A clinician should choose a lab whose technicians are capable using his or her preferred implant systems, CAD/CAM techniques, and alloys. A dental lab should clearly state its policies in regard to outsourcing work to third party providers, including any surcharges passed on to the clinician. A lab's financial policies should be clearly stated to the clinician. An ideal dental lab values quality over quantity when producing prostheses.

The clinician should maintain a checklist of items that need to be sent to the lab when submitting a case. This list may include impressions, models for reference or models of opposing teeth, photographs to communicate tooth shades or other characteristics, wax-ups or templates to convey contours, and occlusal records. The technician should also provide input regarding their requirements for each type of case.

One of the most valuable tools in the communication armamentarium of the clinician is photography. The next few slides will demonstrate some key aspects of clinical photography that are pertinent to communication between clinic and laboratory. The first important element of photography is lighting. The type, power, and positioning of various light sources such as dual-point or diffused ring flashes will affect the quality and type of image obtained. For example, a light source closer to the lens will result in a more evenly lit image, whereas a more distant light source will provide highlights and shadowing. More information on this subject can be found in the ITI Academy Learning Module 'Digital Clinical Photography'.

One of the most useful aspects of photography is the communication of color and shade. Without the patient directly in front of them, the technician can reference their technical work against appropriate photographs to fabricate prostheses that closely match the existing dentition. The use of a widely dispersed light source without a filter can provide details of character and highlights, whereas the use of a cross-polarizing filter allows a more accurate depiction of true shades without the distraction of reflections.

Photographs are most useful if the image that is displayed on the technician's screen is calibrated with the image that was captured by the clinician. A calibration tool such as a neutral balance grey card allows the technician to ensure that the image they see has the same color temperature and characteristics as the original source and image. These images show the use of a neutral balance grey card with and without a cross-polarizing filter. The final color of translucent materials will be affected by the color of their supporting materials. Images of the underlying color can be matched to special die materials to assist the technician in ensuring that the final prostheses appear the same, even when supported by different substrates, such as in this case where adjacent implant- and tooth-supported crowns are being made.

The clinician uses a shade guide to convey information on color, but the gold standard for shade matching is the technician-acquired shade. Dental technicians are well trained and equipped to match shades accurately, and they will use the shade guides and techniques that will be most useful for them. Technicians may take their own photographs, or they may draw shade diagrams outlining various colors, potential porcelains, and stains for fabrication of the definitive prosthesis.

Direct consultation between the technician and patient also provides the opportunity for patients to express their own thoughts and feelings to the technician and for the technician to derive important information about the case. Technicians can also provide valuable input to educate patients about potential prosthetic outcomes by demonstrating various aspects of their existing condition, or by outlining potential problematic aspects that require attention.

The most important piece of information in communicating with the dental lab is the technical prescription. Just as a prescription for a pharmaceutical agent outlines the drug, dosage, delivery method, and frequency, this document outlines the basic information required for the technician to fabricate the intended prosthesis. The following minimum criteria should be specified: prosthesis type, materials, fabrication method, retention method, the components to be used (such as abutment types), shade, stage of fabrication.

More complex cases may require various stages to be checked clinically. If these try-in steps are performed, it is important to relay the results to the technician. These steps may involve diagnostic wax-ups to assess prosthetic contours, metal framework try-ins to verify passive fit, and biscuit try-ins to confirm base shade, contours, and occlusion.

In addition to the prescription, further information pertaining to the case may be helpful to the technician, and a variety of methods are available to communicate this information. While photographs are particularly useful for delivering large amounts of information quickly, diagrams can also help to highlight pertinent aspects of the case. They can succinctly illustrate the clinician's proposed or envisioned prosthesis. The use of an annotated diagram also allows the technician to give feedback and to ask questions about the proposed prosthetic design.

Annotated photographs made with presentation software such as PowerPoint or Keynote are another helpful way of communicating with the technician. The use of such software allows for collaboration between clinician and technician as both parties make further notes or annotations to create together a picture of the proposed prosthesis.

Annotated photographs of clinical situations can also provide valuable information to technicians that would otherwise be difficult or impossible to convey. For example, these images convey to the technician the quantity of enamel that is available for bonding of veneers, as evidenced by the frosted pattern produced by enamel etching. This information would be otherwise unknown if the technician were only provided with an impression or model of the clinical situation.

Another tool for communication between the lab and clinic is the use of photo editing software to digitally alter and manipulate images. Changes to form, outline, color, and transparency can be used to show various treatment stages and their outcomes in both the lab and clinic. This case illustrates the use of digital manipulation to change the opacity of a wax-up. By revealing the underlying contours of the ridge, the degree of soft tissue modification that may be required can be predicted.

The information described in the previous slides is digital; therefore both clinician and technician must be able to manage and transfer the appropriate digital file formats for images, presentations, and CAD/CAM designs. Images may need to be compressed to allow easier transfer or sharing of files. Many modern digital cameras (especially full-frame digital SLRs) will generate file sizes of 10 MB or more per image, which makes the sharing of original-sized files cumbersome and time-consuming. Easy-to-use compression software is highly advantageous for rapid sharing of image files. The ideal compression software can produce clear images with minimal reduction in visual quality, known as 'loss-less compression'. However, it is important to note that original format or 'raw' files may be required for presentation, publication, or medicolegal purposes, and therefore raw files should be preserved or digitally archived.

Once the data file has been acquired, the final consideration is how this digital information should be shared between the lab and clinic. Email is a simple way to transfer files between parties. Although email is a rudimentary method, it has several advantages. Email offers the possibility of end-to-end encryption, thus ensuring data security and patient privacy. Email also has the ability to track correspondence in a conversational context for a particular case. However, a disadvantage of email communication is the single-point, one-way nature of data delivery. Sharing information on a cloud-based platform allows multiple users to access the information at any time. Either party can make changes as required, and the files are updated immediately. Again, the protection of patient-identified data is paramount, and it is important to comply with local regulations relating to the storage and sharing of health data.

The ITI Case Cloud is a useful tool for the storage and sharing of case information. The Case Cloud allows users to upload images, which can be grouped into individual cases. These images can also be captioned and arranged into discrete presentations, which can then be shared publicly. Cases can also be shared privately to selected users who may access the chosen case for viewing, commenting, or editing. The Case Cloud allows the user to link their clinical cases to educational content within the ITI Academy by tagging relevant keywords within the presentation. The ITI Case Cloud removes barriers to case information. By acting as a central silo of information, it allows full-time access for nominated users without waiting across time zones or alerting users separately via emails or other updates.

It may be both prudent and helpful to gain the technician's input in the selection of appropriate components for any particular case, as in this case where angulation correction may be required. However, the selection of implant components is ultimately the clinician's responsibility. Clinicians may sometimes wish to delegate this task to the laboratory, but it is the clinician's duty to know which components have been used in the fabrication of their patient's prosthesis. In some jurisdictions, technicians bear no legal responsibility for the outcomes of dental prostheses once they have been inserted by a clinician, as the quality of the prosthesis should be verified by the clinician. For this reason, implant replicas should be provided separately from the impression, or if in doubt, the master model poured in the clinic and sent to the technician. The attachment of implant replicas into impressions prior to transportation should be avoided, as this creates an extended lever arm with increased potential for tearing or distortion of the impression if the coping moves within the impression past the elastic limit of the material.

An important factor in component selection is the use of genuine products. With the myriad of dental implant manufacturers in the marketplace today, it is easy for clinicians and technicians to employ the use of non-genuine components, and it is ultimately the clinician's responsibility to ensure the use of genuine products. Non-genuine components display lower tolerances of fit, as shown in these images of a genuine abutment and screw, as opposed to a non-genuine abutment and screw, both seated on a Straumann Tissue-Level implant. Larger dead spaces and smaller areas of contact can be seen for the non-genuine products. The use of non-genuine components for prostheses will, in most cases, void the warranty on the implant provided by the implant manufacturer. In all cases, ensure that there is a record of all components used, either provided by the clinician or ordered by the technician for laboratory use. The packaging should be sighted and part and lot numbers recorded into the patient's records.

Information for Laboratory Communication, Key Learning Points: Quality photographic images taken with calibration tools allow the technician to fabricate a prosthesis that closely matches the existing dentition. A shade consultation between clinician and technician is considered the gold standard for shade matching. The laboratory prescription outlines the basic information for fabrication of the prosthesis such as material, method of retention, components, and shade. Annotated diagrams, annotated photographs, and photo editing all improve the collaboration between clinician and technician. Patient information in digital files must be transferred between parties in a secure manner, either via email or on a cloud-based platform such as the ITI Case Cloud. The selection and use of genuine components such as abutments and screws are the responsibility of the clinician.

When technical work is returned from the lab, the following basic questions should be answered: Has the technician provided the prescribed prosthesis, such as a direct-to-implant screw-retained porcelain-fused-to-gold crown? Have genuine components been used, and is there evidence of such? If not, for what reason? Is the prosthesis clinically acceptable in all parameters? In this case, the technician has cemented the prosthesis onto the abutment, but areas of opening are evident at the margin; these were identified to the technician. Finally, is the prosthesis cleansable by the patient? Areas of concavity under a pontic are not appropriately contoured for mechanical cleansing and can trap debris and bacteria.

Use of a structured checklist can be beneficial. A checklist of relevant criteria such as fit, esthetics, contacts, and occlusion provides a qualitative analysis of the laboratory work. This step also serves to ensure that the correct components are present, and it prepares the clinician for the insertion procedure. For example, a checklist helps to ensure that the correct screws are present and ready for insertion. Studies have shown that the use of a checklist can result in improved quality of technical work and improved clinical outcomes. More information can be found in the ITI Academy Learning Module 'Protocol for Fixed Implant-Supported Prostheses Delivery'.

Finally, the use of formal and informal bilateral feedback promotes the teamwork approach between clinician and technician. Providing the opportunity for the lab to give feedback also allows clinicians to improve the quality of their work. Similarly, the technician can provide valuable information pertaining to the delivery of the prosthesis, such as path of insertion or order of seating.

Quality Assessment, Key Learning Points: All work returned from the lab should be carefully evaluated to ensure that it fulfills the prescription and is clinically acceptable. A structured checklist can be helpful in the evaluation process. Feedback from the technician can assist in the insertion of the prosthesis.

Selecting and Communicating with a Dental Laboratory, Module Summary: The dental technician is a partner in the delivery of high-quality dental implant treatment. Ability to coordinate workflows, financial policies, and expertise with the clinician's preferred implant systems and materials are key considerations when selecting a dental lab. It is also important to consider a laboratory's stance on the use of genuine components and its relationship with third-party providers such as CAD/CAM centers. The technical prescription forms the basis of communication with the lab; detailed photographs and a patient-technician shade consultation are recommended supplements to the prescription. Other helpful communication tools include annotated or edited photographs and diagrams; software and digital file sharing greatly facilitate communication using these methods. Secure transfer of digital files containing patient data is paramount. The quality and accuracy of an inserted prosthesis is ultimately the responsibility of the clinician.