Digital Implant Dentistry Predoctoral Program at University of Kentucky

Many dental schools have implemented didactic courses on dental implants.¹  Hands-on clinical courses are beginning to emerge in North America and Europe.^1,2  Yet, many schools worldwide do not have comprehensive curriculum guidelines for implant dentistry education.^1–3  Lack of trained faculty, overwhelmed dental curriculum, and limited financial resources are the most common challenges in many dental schools.^1–3 

A European consensus paper recommended that implant dentistry education should be an integral part of the predoctoral curriculum.⁴  In many instances, implant dentistry education aims to prepare the dental graduate with fundamental knowledge and competencies without expectations of surgical implant placement.⁵  In North America, most dental schools require dental students to take at least 1 implant dentistry course.⁶  However, most schools only offer lectures, hands-on laboratory sessions, and clinical experience in restoring single implant-supported restorations and 2 implant–retained mandibular overdenture with very little study materials.⁶  Some dental schools expect their students to restore selected implant cases and assist in implant surgery.^6–8  It is worth noting that very few schools report that their students perform implant placement surgery and restoration.^5,8 

In 2013, the Commission on Dental Accreditation (CODA) required predoctoral programs to have competency in replacing teeth, including dental implant therapies, with fixed or removable prostheses.⁸  As a result, most US schools teach a prosthetically driven curriculum that includes simulation lab experiences and clinical patient treatments, often involving multiple disciplines.^6,8  In addition, the implant industry reports substantial demand for continuing education courses for surgical implant placement by general dentists.⁹  However, teaching simple surgical implant placement concepts may be better carried out in a predoctoral curriculum, where it is safer for patients under the supervision of trained faculty.^10,11 

A few US dental schools report that dental students can be trained to place posterior implants successfully through special honor programs.^12–16  For students to qualify for such a program, the implant honors students must fulfill several requirements, such as attend a series of lectures providing foundational knowledge in implant prosthodontics and implant surgery; chair-side assisting of multiple implant surgeries; attending a hands-on preclinical session in implant placement; and pass a multiple-choice, take-home examination.^12–16 

University of Kentucky College of Dentistry (UKCD) has a traditional 4-year curriculum with a class of 65 students per year. The first author (A.K.) teaches 4 dental implant courses within the Division of Prosthodontics. Early in the second academic year (D2), students are provided a didactic implant course that introduces patient-centered criteria for implant services, treatment planning, surgical considerations, and a prosthetically driven treatment approach. In addition, the students become familiar with implant terminology and armamentarium, along with all the implant components used in treatment. Finally, the students are provided with hands-on laboratory sessions. They are introduced to the digital dentistry tools, that is, cone beam computed tomography (CBCT), implant planning software, intraoral scanners used in diagnosis and treatment planning for single implant-supported restorations, and implant-retained mandibular overdenture.

The introductory course addresses several CODA standards in patient assessment, diagnosis, comprehensive treatment planning, and prognosis for replacing teeth with dental implants. It contains twelve 2-hour lecture sessions and two 4-hour laboratory hands-on sessions, along with 2 written examinations. The hands-on sessions provide information on the implant restorative system workflow, virtual wax-up, and treatment planning for single implant placement and restoration using treatment planning software. The class is divided into 5 small groups in the digital laboratory for treatment planning purposes. Restoring the implant is accomplished by hands-on procedures in the simulation laboratory.

Students enroll in the advanced dental implantology course that provides a broad range of topics in their third academic year (D3). Lectures cover treatment planning for complex dental implant cases, digital vs conventional implant prostheses, conventional, milled, and printed restorative materials for implant restorations. Moreover, mechanical and restorative complications related to implant dentistry and esthetic considerations for implant restorations are discussed within this course. In addition, immediate implant placement and immediate provisionalization along with soft tissue management for dental implants and site development techniques for future implant placement are reviewed during the study. Various loading protocols are presented with all previous topics in eight 2-hour lectures. For the hands-on components of this course, students learn how to do digital implant impression technique and virtual treatment planning of 2 implant–retained mandibular overdenture using dual scan protocol using treatment planning software. A simulation-guided implant placement technique in plastic models is offered in three 4-hour laboratory sessions, 2 written examinations, and 1 hands-on competency. The competency allows the student to virtually treatment plan an implant case independently using the treatment planning software. This serves as part of the evaluation methods for the course.

In their fourth academic year (D4), students are offered 2 elective preclinical and clinical implant courses. One course is advanced digital implant dentistry that offers preclinical hands-on experiences. Students enrolled in this course explore multiple implant systems', digital workflows, and different digital technology. The students acquire information on current robotic digital technology in implant dentistry. They use various implant systems' software and tools for implant placement and perform multiple surgical procedures, such as maxillary sinus augmentation, “vertical and horizontal techniques,” extraction socket graft, incisions and flap designs, and suturing techniques. All this is accomplished in eight 2-hour simulation laboratory sessions. The other clinical elective course provides the clinical opportunity to place a dental implant. All fourth-year students are encouraged to place at least 2 implants in patients using the fully guided surgery protocol.

The purpose of this report is to describe a comprehensive digital approach to a fully guided single implant placement and restoration program in the UKCD predoctoral clinics.

Surgical dental implant education is increasingly becoming part of predoctoral dental curricula.¹¹  The CODA suggested that “Technology enables dental education programs to improve patient care and revolutionize all aspects of the curriculum, from didactic courses to clinical instruction."¹⁶ UKCD predoctoral implant program introduces basic surgical concepts and principles related to fully guided implant surgery in the predoctoral clinics (Figure 1). In addition, students learn clinical principles of minimally traumatic extraction with ridge preservation, digital impressions for virtual treatment planning (Figure 2), surgical fully guided dental implant placement, and complete digital workflow for implant restorations (Figure 3).

The objectives of digitally guided surgery protocol in the predoctoral clinic are:

1. Use evidence-based scientific information to perform minimally traumatic extraction, manipulate bone graft, and resorbable collagen membrane and learn suturing techniques.

2. Prepare surgical field based on asepsis and sterility protocol relevant to implant placement.

3. Use evidence-based scientific information for digital impressions and virtual implant planning clinical cases.

4. Use a three-dimensional (3D) printed surgical guide to surgically place a fully guided implant for simple single unit cases.

5. Create digital impressions to design final implant-supported restoration through a complete digital workflow for single implant cases.

Upon course completion, students should be able to do the following:

• Select appropriate patients for implant surgery and restorations for the general practice setting.

• Design treatment plans for implant cases and recognizes possible local and systemic risk factors.

• Choose the appropriate surgical and restorative protocols using digital technology.

• Manage patient pre-and postoperative care.

• Implement dental implantology knowledge into future general dentistry practices.

Prosthetically driven implant placement is a critical factor for successful implant therapy.¹⁶  Computer-assisted implant surgery (CAIS) offers an additional tool for treatment planning, surgical placement, and prosthetic rehabilitation in an interdisciplinary team approach.¹⁶  In addition, the continuous technological improvement in both the computer-based development and the dental manufacturing process ensures new opportunities in the digital clinical workflow.^16,17 

• Simple single implant unit in the premolar or molar region

• No fixed partial denture (FPD) or removable partial denture (RPD) in treatment plan

• No hard or soft tissue grafts are needed at the edentulous site

• No further surgical procedure corrections are required at the proposed implant site

• Minimum restorative space: height, 6 mm; mesio-distal, 6 mm; bucco-lingual, 6 mm

• Third- and fourth-year students who restored at least 1 dental implant in their second academic year (D2)

• Intra-Oral (IO) Scanners

  • 12 Trios IO Scanners (3shape, Inc, New Providence, NJ)

  • 23 Straumann PF2 IO Scanners (Straumann USA, Andover, MA)

  • 2 Straumann Virtuo Vivo IO Scanners - Laptops (Straumann)

  • 5 Straumann Virtuo Vivo IO Scanners - Single Units (Straumann)

  • 2 iTero Element 2 Scanners (iTero, Align Technology, Inc, San Jose, California)

  • 4 PlanMeca IO Scanners (Planmeca USA Inc, Hoffman Estates, IL)

  • 6 Cerec Omnicam Scanners (Dentsply Sirona, Charlotte, NC)

• Desktop Scanners

  • 3 Straumann 7 series desktop scanners (Straumann)

  • 1 3Shape E4 desktop scanner (3shape)

• 3D Printers

  • 2 Formlabs 3B 3D printers (Formlabs Inc, Somerville, MA)

  • 1 Rapidshape P30+ 3D printer (Straumann)

• Milling Machines

  • 1 AG M series mill (Straumann)

  • 1 Ivoclar PrograMill PM7 mill (Ivoclar Vivadent, Inc, Amherst, NY)

  • 4 E40 mills (Planmeca)

• Computer-aided design (CAD) Software

  • 30 Straumann Cares Visual lab CAD software (Straumann)

  • 30 Straumann Chairside design software (Straumann)

  • 20 3Shape Dental Systems Lab CAD software (3shape)

  • 4 Planmeca chairside CAD (Planmeca)

  • Unlimited Compare software Planmeca

• Guided Surgery Software

  • 35 Straumann CoDiagnostix guided surgery software (Straumann)

  • 20 3Shape Implant Studio guided surgery software (3shape)

• 3 i-Cat brand CBCT machines and 1 limited view CBCT (Carestream, Rochester, NY)

1. Diagnostic CBCT

2. First intraoral or model surface scan

3. Virtual computer-based implant planning

4. Surgical guide for fully guided protocol and 3D printed model

5. Guided implant surgery

6. Second intraoral or model surface scan with scan body

7. Design and fabricate the screw-retained or cement-retained implant-supported restoration

8. Prosthetic rehabilitation treatment

The extraction procedure is performed under local anesthesia following the routine administration of prophylactic antibiotic medications consisting of 2 g amoxicillin 1 hour before the surgical procedure. Patients allergic to penicillin will have prophylactic antibiotic medications consisting of clindamycin 600 mg at 1 hour before the surgical procedure. Minimally traumatic extraction protocol is followed, including an intrasulcular incision around the nonrestorable tooth to cut the connective tissue fibers above the bone and detach the connective tissue fibers from the cementum (Figure 4a). The Physics Forceps (GoldenDent, Roseville, MI) is used as a minimally traumatic extraction system that provides a simple, predictable, and unconventional extraction regardless of the tooth's condition. The Physics Forceps operates as first-class lever mechanics to elevate and luxate the tooth and extract it (Figure 4b). The extraction socket is then curettaged to remove all granulation tissue and fibers and rinsed with sterile water (Figure 4c). The bone graft is then delivered using a preloaded syringe (RegenerOss Allograft Putty Plus Mineralized, Zimmer Biomet Dental, Palm Beach Gardens, FL) to fill the socket gingival margins. Resorbable collagen membrane (Zimmer Socket Repair Membrane, Zimmer Biomet Dental) is used to protect the graft materials and is secured with nonresorbable PTFE sutures (OsseoGuard Polytetrafluoroethylene (PTFE) Suture, Zimmer Biomet Dental) (Figure 4d).

coDiagnostiX software (Dental Wings, Montreal, QC, Canada) ensures the planning of the implant position using CBCT with digital imaging and communications in medicine (DICOM) data and the subsequent transfer of the virtual situation into reality with a multidisciplinary team approach, including the restorative dentist, the implant surgeon, and the dental laboratory technician. This clinical case presentation demonstrates the digital implant workflow systematically with computer-assisted implant surgery (CAIS), including surgical and prosthetic rehabilitation in a 5-step approach¹⁷:

Step 1. Optical scan. A good quality stone model (from PVS impression) scanned by an optical dental laboratory scanner or teeth are scanned directly with an intraoral scanner (Figure 5). This is an essential step to the entire case and one of the most critical keys to getting the correct outcome. The quality of the impression (physical or digital) controls the quality of the surgical guide in terms of accuracy.

Step 2. CBCT scan of the entire arch. Teeth to be separated during image acquisition with cotton rolls on both sides or bite registration (Figure 6).

Step 3. Wax-up of the final prosthesis (physical or virtual) allows prosthetically driven planning (Figures 5 and 6).

The DICOM data and the STL file are imported and superimposed in CoDiagnostiX planning software. Then, based on virtual setup or physical wax-up of the prosthetic reconstruction, a surgical template with optimal 3D implant positioning is designed using a restoration-driven reverse planning concept while considering the individual anatomical situation (Figure 7).

Once the planning phase is finished, a 3D printer can plot the virtual construction of the surgical template with the rapid prototyping technique (Figure 8). Next, the patient's upper and/or lower cast (3D printed model) is printed using a 3D model printer (Straumann CARES® 3D Printing Solutions, Straumann USA, Andover, MA). The STL data cannot perform any quality control work without a 3D printed model to guarantee a proper guide manufacturing process. Finally, CoDiagnostiX delivers an individual drilling protocol with sequenced CAIS instruments for safe 3D implant placement using a 3D printed guide.

Before implant surgery, the surgical guide is checked for a precise fit (Figure 9).

(1) The 3D printed model: Verifies accurate surgical guide printing as the 3D model is produced on the same STL file but with a different machine. If the fit is not adequate, the 3D printing process is inaccurate. In addition, the implant position and direction need to be verified as well.

(2) On the patient cast if available: Verifies possible impression inaccuracies and errors in the optical scanning process

(3) In the patient's mouth: For educational purposes, students performed a simulation of fully guided implant placement surgery on a 3D printed model before the actual surgery on a patient, after administering local anesthesia following the routine prophylactic antibiotic medications consisting of 2 g amoxicillin 1 hour before the surgical procedure. Patients allergic to penicillin have prophylactic antibiotic medications consisting of clindamycin 600 mg at 1 hour before the surgical procedure. A flap/less prosthetically driven guided surgery workflow is used to prepare the osteotomy for implant placement. Following the guided surgery drill protocol, an osteotomy is prepared using a sequential drilling system for a Straumann implant (Figure 10). Once the implant is placed through the guide and primary stability is obtained, peak insertion torque is immediately measured. Next, implant stability quotient (ISQ) measurements are recorded using resonance frequency analysis (RFA) from Osstell mentor (BioHorizons, Birmingham, AL). Using SmartPeg (Emerginnova LLC, Miami, FL) attached to the implant platform using the manufacturers' guidelines, the ISQ value is calculated. Then the SmartPeg is detached, and the cover screw or healing abutment is installed using the manufacturers' prosthetic kit connected to the implant fixture. The patient is recalled at 14 days for follow-up suture removal and 2 to 3 months after surgery for definitive restorations.

A second STL file is created after implant healing with an appropriate emergence profile based on a new intraoral optical impression using an implant scan body or actual implant model scan (Figure 11). This STL file is then imported into CoDiagnostiX. Moreover, the implant-supported prosthetic suprastructure is designed and fabricated after the healing period. All necessary information about the actual implant position is included in the second STL file at this time. Finally, the CAD/computer-aided manufacturing (CAM)-fabricated implant abutment and crown are milled using the Straumann milling machine (Straumann M series) (Figure 12).

The abutment and crown are tried in and evaluated for any interproximal or occlusal adjustments to optimize the functional treatment outcome and clinical esthetic results. The restoration is torqued to 35 Ncm, and the screw access is filled with Teflon and covered with a composite restoration.

The UKCD dental implant training program was started in 1999.¹⁸  Previously, placement of dental implants was only performed by graduate students in periodontology or oral and maxillofacial surgery. Restorations of these implants continue to be done by predoctoral students. The program is a single implant system (Straumann) used for case selection based on evidence-based protocols for diagnosis and treatment planning. The program is structured on incremental learning experiences in a comprehensive, system-specific instructional curriculum. Dental students involved in treatment planning and restoring the implants are required to assist residents during the surgical placement of implants. Patients are seen for follow-up, maintenance, and ongoing process improvement via the Implant Quality Assurance Program.¹⁸ 

Since 2018, UKCD has established a predoctoral comprehensive implant program and is reported here to allow comparison and implementation in other universities. However, challenges remain in developing strategies to implement competence profiles and the extent of experience-based education.¹⁹  Although UKCD has a computer-aided dynamic implant navigation system (X-Nav Technologies, Lansdale, PA) that can be explored in the predoctoral implant program, a fully guided implant surgery protocol for single implant placement was implemented to ensure safety. Golob Deep et al²⁰ found that computer-aided dynamic implant navigation systems can improve implant surgical training in the novice population. They found males were marginally faster than females, had slightly lower overall 3D angulation, and reported higher proficiency with video games. Novice operators improved significantly in speed and angulation deviation within the first 3 attempts of placing implants using dynamic navigation.^20,21 

The implant training program includes fully guided implant placement hands-on 3D printed models to simulate the actual implant surgery. At UKCD, all students go through this training in their third academic year (D3) and again before performing the implant surgery on a patient for the first time. The students placed dummy implants for 2 types of fixtures: tissue-level and bone-level implant designs. Students' feedback after the hands-on training was positive in simplifying the procedure and simulating the real scenarios. As reported in the literature, preclinical hands-on training was considered effective in motivating the students toward clinical implant treatment.^22–26  Unfortunately, few clinical implant programs are offered in North America. Almost all of them are selective to a specific number of fourth-year students.^12,27–32 

In general, most dental students do not continue into advanced postgraduate programs and are likely to learn surgical implant placement in weekend continuing education courses. Our program is unique by allowing all dental students to gain experience in placing at least 2 implants surgically before they graduate. This is possible by incorporating digital technologies in the form of guided surgery and full digital restorative workflow.^33–35  Due to COVID-19, UKCD and most other universities closed for several months, negatively impacting all educational and clinical activities and experience. Even with these obstacles, the UKCD dental students placed a total of 294 implants. Unfortunately, 6 implants failed in early healing time due to infection. The overall success rate was 98%. Moreover, predoctoral students have completed 184 second-stage surgeries through this program to expose implants, 168 minimally traumatic extractions and socket grafting procedures, and 292 miscellaneous procedures, including digital impressions and restorations. Also, having dental students manage implant complications is another advantage in this experience. A survey-based study on implant complications in the predoctoral programs showed similar trends to the complications reported in the literature.³⁶  However, implant curricula in US dental schools need improvement in teaching the diagnosis and treatment of implant complications.³⁶  Within the teaching implant program at UKCD, students have the opportunity to learn comprehensive surgical and restorative implant treatments that provide a wide range of experience for them when they become practicing dentistry after graduation. Patients' perception and satisfaction with implant treatment in predoctoral programs significantly impacted their quality of life.³⁷  These patients report a high level of satisfaction.³⁷ 

Based on our short-term experiences developing and implementing a fully guided surgical implant placement program at UKCD, we recommend that surgical implant courses become part of the predoctoral curriculum and be integrated throughout core courses in dental education. This report serves as a protocol for curriculum development that other dental schools can use to enhance surgical implant experience for graduate general dentists.

The authors thank Sarah Windhorn, the digital surgical suite coordinator and dental surgical assistant at UKCD, and Steven Tucker and Cheryl Pearson for participation in the Implant Clinics.