Surgical Techniques in Oral Implantology
Introduction :
Implant therapy has become essential in the overall care of our patients for several years. This discipline has continued to evolve since the principles set forth by Brånemark, offering us a multitude of protocols.
I. Conventional implant surgery with flap:
1. One- or two-stage surgical protocols:
With current implantology practice emphasizing simplification of procedures, the one-step protocol has become the standard. However, these two protocols are complementary and achieve identical results. Therefore, there are no specific indications differentiating them, only guidelines that will guide the practitioner in choosing their therapy.
1.1. Two-stage surgical protocol (Buried technique):
To ensure high success rates, modern implantology according to Brånemark required a two-stage surgical approach. It had to follow the wet-nurse technique, with two-piece implants, i.e., separate implant and transmucosal abutment.
Burial during the bone healing period was intended to allow (Brånemark et al. 1969 and 1977):
- To prevent apical migration of the epithelium along the implant;
- To effectively protect against bacterial infection;
- To minimize the biomechanical stresses transmitted to the bone-implant interface during healing.
First surgical step:
- Local anesthesia is performed with solutions containing a vasoconstrictor, allowing intervention in a low-blooded environment. For the posterior mandibular area, locoregional anesthesia at Spix’s spine should be evaluated because the patient’s painful sensitivity near the inferior alveolar nerve can be an intraoperative aid;
- Incisions: This is the first surgical procedure when placing implants, followed by the detachment of a mucoperiosteal flap, which will allow access to the underlying bone. Regardless of the implant site and the number of implants placed, we will choose our incision path with the priority of minimizing discharges, obtaining peri-implant keratinized tissues and preserving the papillae. These objectives will be compared with the quality of the periodontium, the desired aesthetics or the need to visualize the underlying bone;
- Pre-drilling, or marking of the bone, will be done with a round burr;
- Initial drilling, 3 to 4 mm deep. Pass a first drill then a guide rod to validate the two initial parameters: the emergence point and the axis that the implant must have;
- Sequential drilling using several drills of increasing diameter until the bone site is calibrated according to the implant to be placed. Drilling must be done under abundant irrigation. The rotation speed decreases in parallel with the increase in the diameter of the drills;
- Implant placement: The implant is removed from its double sterile packaging and fitted with an implant holder. Screwing is initiated by aligning the major axis of the implant with that of the recipient site. The implant is buried using either a 15 rpm speed-reducing contra-angle handpiece or a manual wrench. Screwing is stopped when the implant neck is flush with the bone crest. Screwing must be gentle without excessive force. When the implant is correctly positioned, the implant holder is removed and the thread protection screw, known as the cover screw, is installed;
- Hermetic sutures: This involves obtaining the most hermetic coaptation possible of the edges around the cover screw. Several suture techniques can be used depending on the clinical situation. The goal is to ensure that there is no mobility of the flap so as not to interfere with healing;
- A one-week post-operative check-up is necessary to remove the sutures.
Second surgical stage:
After the wet-nursing period (historically, 6 months in the maxilla and 4 months in the mandible), and radiological control of osseointegration, the second surgical stage or mucosal stage can be considered:
- After local anesthesia, the incision is followed by elevation of the flap which allows access to the cover screw and its removal. It is often necessary to resect a layer of newly formed bone to release this cover screw;
- The cover screw is replaced with a suitable healing screw, which helps guide mucosal healing. Radiographic monitoring of screw fit is often necessary;
- The flap is sutured with simple stitches, coapting the edges between the healing screws, with mucogingival arrangement if necessary, to improve the environment of the keratinized tissue in terms of quality and thickness. Gingival healing and maturation extend over a period of 6 to 8 weeks. The healing screw is then unscrewed to begin the prosthetic steps.
According to this approach, bone and mucosal healing are chronologically staggered. During the first 4 to 6 months, the bone heals, and the mucosa will not take its final form until after the reoperation.
1.2. One-step surgical protocol (non-buried technique):
One of the first developments in the protocol was single-stage surgery. Indeed, some researchers, including Schroeder, have demonstrated that implant burying is not a prerequisite for osseointegration.
The one-stage surgical protocol is originally performed with one-piece implants, meaning that the implant and its neck are in contact with the hard tissues and the gums in a single piece. However, this protocol can also be applied to two-piece implants intended for a two-stage surgical protocol but placed according to a one-stage surgical protocol.
In the surgical technique for non-submerged implants, the implant placement is identical. The difference lies in the direct exposure (immediate placement of a healing screw), without the implant being placed in a wet bag during osseointegration. The implant is not then isolated from the oral environment because it is exposed via the healing screw. In addition, it is not exempt from all biomechanical forces because the peripheral muscles (such as the cheeks and tongue) will be in contact with it.
The one-step protocol will allow:
- To provide greater comfort to the patient who is only undergoing one surgical procedure;
- A reduction in overall implant treatment time;
- To control osseointegration during the healing phase.
1.3. Comparisons of one-stage and two-stage protocols and indications:
Hard and soft tissue responses are not affected by the surgical protocol chosen. Indeed, numerous clinical and animal studies comparing one-stage and two-stage implant placement conclude that osseointegration is identical for both protocols (Gotfredsen et al, 1992; Levy et al, 1996; Ericsson et al, 1996; Abrahamsson et al, 1999).
There are, however, preferential indications for these two protocols. Certain situations may lead the practitioner to prefer a two-stage surgical protocol:
- Poor primary stability , in order to avoid stress on the implant by the tongue, cheeks or even the food bolus;
- Unfavorable biomechanical environment : Parafunction (bruxism, etc.), muscle insertion in the immediate vicinity of the implant, wearing a removable prosthesis during the temporization phase;
- Insufficient oral hygiene ;
- Aesthetic requirements , if the soft tissue profile is difficult to anticipate precisely, or if the gum presents a deficit in quantity and quality (burial allows the re-creation of better preparatory conditions for a subsequent increase in the volume of soft tissue, by bone or connective tissue graft).
- Tissue development , if tissue augmentation is planned in order to avoid early exposure and therefore loss of regenerated bone volume.
II. Flapless implant surgery (“flapless” technique):
Conventional implant surgery is now supplemented by surgical techniques that may not require the creation of mucoperiosteal flaps.
Flapless implant surgery involves drilling the edentulous ridge directly through the mucosa. Thus, the “flapless” technique has been the subject of discussion among practitioners for several years: too risky and dangerous for some, beneficial and advantageous for others. This technique carries a high risk of complications if it does not include a surgical guide, the lack of precision is then very significant, it is a completely “blind” surgery.
III. Computer-assisted implant surgery:
Computer-assisted implantology (CAI) is a new discipline that combines the capabilities of computer science and dental rehabilitation implant surgery. Having entered the field of prosthetics in the form of computer-aided design and manufacturing (CAD-CAM), computer science now offers assistance to practitioners in planning and executing their surgical procedure and in preparing a temporary prosthesis, which can be made even before surgery.
The use of IAO allows three distinct and independent applications from each other:
- Planning the treatment plan;
- Guided surgery during implant placement;
- The preparation of a single, partial or total prosthesis, even before surgery has taken place.
IV. Healing time before implant placement:
Following research by Chen and Buser, a classification system regarding the timing of implant placement after tooth extraction was proposed at the 3rd ITTI (International Team for Implantology) Consensus Conference in 2003: Four implant protocols based on morphological, histological and dimensional changes of the extraction socket over time were described, and the advantages and disadvantages of each placement type were listed.
| Classification | Descriptive terminology | Post-extraction delay |
|---|---|---|
| Type 1 | Immediate installation | Immediately |
| Type 2 | Early placement after healing of soft tissues | 4 to 8 weeks |
| Type 3 | Early placement after partial bone healing | 12 to 16 weeks |
| Type 4 | Delayed installation | ≥ 6 months |
Classification of the timing of implant placement after tooth extraction According to Chen and Buser
Buser explains in a review that immediate implantation should be considered a complex procedure that should only be performed by experienced clinicians, when ideal anatomical conditions are present. This includes:
- A fully intact vestibular wall at the extraction site;
- A thick gingival biotype;
- Absence of acute infection at the extraction site;
- Sufficient apical and palatal bone volume at the extraction site to allow implant insertion in a correct three-dimensional position with sufficient primary stability.
If these ideal conditions are not met, the ITI recommends early implant placement (Type 2) after 4 to 8 weeks of soft tissue healing. In cases where primary stability is not expected to be achieved after 4 to 8 weeks, post-extraction healing should then be extended to allow for partial bone healing (Type 3).
Conclusion :
Different implant surgical protocols are thus available to the practitioner faced with the multitude of clinical situations encountered, differing from each other by the time of placement of the implant in the socket following extraction, by the duration of treatment, the loading time or even the healing of soft and hard tissues.
Bibliography:
- Davarpanah M, Martinez H, Kebir M, Tecucianu JF. Manual of clinical implantology. Rueil-Malmaison: COP JPIO collection. 1999.
- Davarpanah M, Szmukler-Moncler S, Collective. Manual of clinical implantology: Concepts, integration of protocols and outline of new paradigms. 3rd edition. Rueil-Malmaison: Éditions CdP, coll. JPIO, 2012.
Surgical Techniques in Oral Implantology
Wisdom teeth can cause infections if not removed in time.
Dental crowns protect teeth weakened by cavities or fractures.
Inflamed gums can be a sign of gingivitis or periodontitis.
Clear aligners discreetly and comfortably correct teeth.
Modern dental fillings use biocompatible and aesthetic materials.
Interdental brushes remove food debris between teeth.
Adequate hydration helps maintain healthy saliva, which is essential for dental health.