Editor’s note: The highly anticipated Chinese version of “Non dental Implant Treatment” is about to be released. The book is written by a team of authoritative experts in the field of non dental implants and is designated as a clinical textbook by the British Dental Association (BDA). The book is divided into 17 chapters, with more than 2000 exquisite pictures, drawings, and tables, systematically explaining the principles and technical details of non dental implant treatment for patients with non dental implants! Authorized and approved by the publishing house, we have specially released some exciting content of the new book to entertain readers! (Disclaimer: The shared content has been re edited and differs from the book!)

Editor in Chief: Professor Saj Jivraj’s Speech

01
Clinical background
The use of implant supported restorations for the restoration of edentulous patients is a major challenge faced by physicians. Because patients have high expectations in terms of aesthetics, pronunciation, morphology, function, and other aspects. The assessment of edentulous patients is quite complex, as they not only lose the height of their clinical dental crowns, but may also experience continuous pain of soft tissue and bone tissue loss after tooth loss, accompanied by changes in facial morphology. Most patients expect to obtain fixed dentures through implant restoration. Try to avoid bone grafting surgical methods as much as possible, especially All-on-4 ® The introduction of implant fixation has changed the treatment mode for edentulous patients (Figure 1).

All-on-4 with upper and lower edentulous jaws ® Fixed repair
Nowadays, as long as the indications are met, implanting four implants in a single jaw can achieve full arch restoration of the entire dental arch. The main advantage of this method is that it reduces the number of implants and avoids large-scale bone grafting operations. This repair method not only meets the needs of aesthetics and functionality, but also greatly reduces the cost for patients. As a result, there has been an increase in patient acceptance and a rise in the number of patients receiving treatment. The number of edentulous patients is constantly increasing, resulting in a shortage of trained dentists to provide treatment for them. Diagnosis and design are crucial for achieving the expected results in the treatment of edentulous jaw. Incomplete or incorrect diagnostic designs can lead to unsatisfactory results for both patients and physicians. Below, we will briefly explain the “seven elements” in the design of dental implant therapy for edentulous jaw.

02
The “Seven Elements” of Dental Implant Restoration Design
Physicians need to determine whether patients are more suitable for fixed dentures or removable dentures based on some clinical parameters. Zitzmann, Marinello, and Jivraj elaborated on the parameters that need to be evaluated. Before evaluating all diagnostic criteria, patients should not be promised the ability to undergo implant fixation repair (Figure 2); Remember not to implant an implant before a clear treatment plan is established, as the position of the implant may vary depending on the type of restoration.

Factors to Consider Before Deciding on Implant supported Fixed or Removable Dentures for Restoration
From the perspective of diagnostic design, the following 7 key parameters need to be evaluated to determine the most suitable type of restoration for the patient; We refer to it as the “seven elements” in the design of edentulous jaw fixed restoration treatment: ① the position of the upper and lower jaw cutting edges; ② Repair space; ③ Lip support; ④ The length of the smile line and lips; ⑤ Appearance and gingival contour; ⑥ Organize contact in the conversion zone; ⑦ Bite.

The position of the upper and lower jaw cutting edges
The determination of the cutting edge of the maxillary central incisor requires reference to aesthetics and pronunciation. Traditional guidelines suggest that when a patient produces an F-sound, the cutting edge should touch the labial red edge of the lower lip. Once the length, axial angle, and shape of the crown are determined, the distance between the gingival margin of the crown and the remaining alveolar bone can be determined to determine if there is enough space for the expected repair.

Adjusting the position of the cutting edge towards the root will affect the placement of the implant
When patients with end-stage dentition visit, the maxillary incisors are usually too long, so the treatment plan should reposition the cutting edge to a more root position (Figure 3). Due to the presence of free gingival margins, placing the maxillary central incisors in the correct position may require lowering the height of the alveolar bone to provide sufficient space between the implant neck and the gingival contour (Figure 4).

Using bone removal guides to provide surgeons with measurement reference points from gingival margin to bone margin

Repair space
Insufficient repair space is a common mistake in the design of edentulous dental restorations. Insufficient repair space can cause early failure of the restoration (Figure 5), or force a change in treatment plan to choose another repair method that can meet the existing space.

Insufficient repair space can lead to the fracture of the restoration
Different types of restorations have different space requirements, for example, acrylic resin&titanium based restorations require 14-16mm of space (Figure 6). Adequate repair space is crucial, as it must have enough space to accommodate a sufficient amount of repair materials, while also allowing the restoration to achieve aesthetics and be easy to clean. If space is limited, vertical height reconstruction or adjustment of the patient’s bite should be considered.

Resin restorations require a repair space of 15-18mm
Lip support
It is necessary to evaluate the facial support on the front and side of patients with and without dentures separately, so that clinicians can determine which type of restoration is more suitable (Figure 7).

Observing the patient’s profile with and without dentures can indicate whether a labial support is needed
If there is a significant horizontal deviation between the expected position of the teeth and the implant, the following treatment options must be considered before implant placement:
① Lowering the bone height and implanting the implant in a more square position can provide lip support and facilitate cleaning of the restoration contour (Figure 8- right). If the bone height is not lowered, it will form a poor restoration contour (Figure 8- left), making it very difficult for patients to maintain hygiene.

If a patient with poor lip support wants to have a fixed dental implant, they need to undergo bone removal and implant the implant in a more square position, so as to make the position of the restoration higher
② Le Fort I osteotomy: Most patients are unwilling to undergo this type of surgery.
③ The most commonly chosen clinical treatment method is removable dentures with labial abutments supported by implants.

The length of the smile line and lips
Patients with end-stage dentition often have excessive gum exposure. Before starting treatment, clinicians must carefully evaluate the movement of the patient’s upper lip during speaking and smiling, as well as the length of the lips. Patients with shorter upper lips may have their maxillary anterior teeth exposed during rest (Figure 9), causing aesthetic issues.

Cases with short upper lip are more challenging, and the transition zone may be exposed
Ask edentulous patients to smile with and without dentures (Figure 10).
Figure 10: For edentulous patients, having them laugh heartily after removing their dentures. If the alveolar ridge is visible, bone removal may be necessary to conceal the transition area, depending on the type of restoration
If the soft tissue of the alveolar ridge cannot be seen, the transition zone between the implant supported restoration and the remaining alveolar ridge cannot be seen, and the color and contour changes of the restoration at the soft tissue junction can be relatively flexible. If the alveolar ridge is exposed when smiling, the aesthetic aspect will be very challenging because the contact area between the restoration and the gingival complex is visible, which poses aesthetic risks and requires necessary measures to be taken.

The length of the smile line and lips
The shape of the restoration must be planned from the beginning. Starting from the gingival margin, the gingival contour of the restoration should be straight (Figure 11); This usually requires trimming the alveolar ridge to create enough space.

Figure 11: The gingival contour of the implant restoration should be straight
Restoration physicians can utilize this space to achieve good mechanical mechanics, aesthetics, and ease of cleaning. The required repair space can be conveyed to the surgeon through the bone removal guide plate, and the surgeon will perform the surgery. There is a misconception among people about surgical plans that do not involve bone grafting, often believing that a large amount of bone removal is required. Bone removal must be justified, and in order to meet the needs of implanting implants and making biomechanical restorations, bone removal must be minimized as much as possible.
At any level of oral restoration, temporary restoration is the key to the success of permanent restoration. For patients, aesthetics and pronunciation are important. Physicians need to pay more attention to biomechanics, occlusion, and the convenience of cleaning. Temporary restorations/immediate weight-bearing restorations must meet the following criteria:
① Reduce food accumulation: After a 3-month healing period, the acrylic resin temporary restoration should be re lined to compress the soft tissue, forming a concave soft tissue surface to accommodate the convex tissue surface of the restoration (Figure 12).
Figure 12 requires shaping of soft tissue through temporary restorations. When the physician takes the mold, the soft tissue should be concave (left), and the tissue surface of the temporary restoration for immediate weight-bearing must be convex and highly polished (right)
② Forming soft tissue to create a cleanable contour.
③ Eliminating pronunciation barriers: The pronunciation of T and D is related to the palatal surface of the maxillary prosthesis and can be adjusted according to the specific situation in this area.
④ The contact with soft tissue should be tight and can be cleaned at the same time.
⑤ The tissue surface of the restoration should be highly polished.

occlusion
There is currently no literature supporting any occlusal design, which is superior to others, or which occlusal design patients prefer in terms of occlusion. The occlusal considerations for temporary restorations with immediate weight-bearing should include but are not limited to the following aspects: ① The distribution of implants should meet good A-P distance; ② The smallest cover; ③ Simultaneous bilateral contact; ④ No interference on the side; ⑤ Resin restorations fixed with screws can achieve passive positioning and stability across dental arches, and have sufficient rigidity to prevent breakage under stress; ⑥ No cantilever beam; ⑦ The occlusal contact is limited to the range of canines, and Shimstock bite paper can be withdrawn when biting in the posterior region.

03
Summary
Compared with traditional edentulous dental implant restoration methods, the use of non bone grafting techniques for edentulous dental implant restoration is more challenging. Correct diagnosis and appropriate treatment plan are crucial for achieving success. The concept of oral implantation has undergone significant evolution, not limited to design, materials, and implant surface treatment. Clinical physicians can only better plan implant restoration plans by having a clearer understanding of surgical and restorative procedures and grasping the “seven elements” mentioned above.