Immediate Implant Placement: A Tooth-by-Tooth Clinical Rationale

Introduction

Immediate implant placement has become an increasingly predictable treatment modality in modern implant dentistry. However, in my opinion, the discussion should not start with implant systems, implant diameters, or drilling protocols. Instead, it should start with anatomy, biology, prosthetic requirements, and the source of primary stability.

Throughout my clinical practice, I have progressively moved away from a tooth-based implant selection philosophy and toward an anatomy-driven approach. Although this chapter is organized according to tooth position, the reality is that implant selection is dictated by the available bone, socket morphology, restorative requirements, and long-term maintenance considerations rather than by the tooth itself.

The same implant may therefore be used in completely different tooth positions for entirely different reasons. Likewise, the same tooth position may be restored using different implant designs depending on the anatomy present at the time of extraction.

The purpose of this chapter is to summarize my current rationale for immediate implant placement according to tooth position and to explain the biomechanical and prosthetic principles that guide my decision-making.

Maxillary Central Incisor

For the maxillary central incisor, my workhorse implant is typically a BLX 4.0 × 10 mm implant. When the implant is placed approximately 2 mm apical to the crestal bone, I find that the majority of patients have sufficient anatomy to accommodate either a BLX 4.0 mm or a BLX 3.5 mm diameter implant with a 10 mm length. In selected cases with greater available bone volume, I may choose a 12 mm implant.

Socket anatomy and implant macrogeometry also influence implant selection. I frequently use the TLX 3.75 NT hybrid implant. In most immediate central incisor cases, I select the 10 mm version. Given its 1.8 mm machined collar, the overall implant length occupying the socket is effectively close to 12 mm. I have found this to be an excellent balance between ease of drilling, primary stability, and long-term outcomes.

My clinical rationale is based on maximizing primary stability while preserving as much native bone as possible. I routinely apply the BLT drilling protocol when using both BLX and TLX implants.

For a 3.75 mm TLX NT implant, I typically prepare the osteotomy with the 2.2 mm drill followed by the 2.8 mm drill. I then use the BLT 3.5 mm drill only at the socket entrance to facilitate implant insertion. Similarly, when placing a 3.5 mm BLX implant, I generally prepare with the BLT 2.2 mm drill and use the BLT 2.8 mm drill only at the coronal aspect of the osteotomy.

Regarding the use of a polished collar, my rationale is equally straightforward. In immediate implant placement, the coronal portion of the implant is frequently exposed to a combination of xenograft material and soft tissue rather than being completely surrounded by native bone. In this environment, I believe a polished collar offers a more stable and biologically favorable interface than a roughened surface.

In selected cases, I also use the Biomet 3i T3 Pro implant. One of the reasons I appreciate this implant is its straightforward drilling protocol and the reproducibility with which excellent primary stability can be achieved.

Ultimately, my philosophy remains simple: preserve bone, maximize primary stability, position the implant prosthetically, and create the most favorable biologic environment for long-term tissue stability.

Maxillary Lateral Incisor

For maxillary lateral incisors, I generally favor small-diameter implants with an apically tapered design. My preferred choice is often the BLT 3.3 mm implant because its tapered apical morphology provides excellent flexibility when working in close proximity to adjacent roots.

However, root proximity is not a challenge in every case. In many patients, there is sufficient native bone volume and adequate mesiodistal width to accommodate a wider implant. In these situations, I typically prefer a 3.5 × 10 mm or 3.5 × 12 mm BLX implant.

Unlike central incisors, I do not routinely favor a hybrid implant concept for lateral incisors because the implant is usually surrounded by native bone due to the narrow dimensions of the lateral incisor socket.

Maxillary Canine

For maxillary canines, my rationale is largely similar to that of the central incisor. The primary objectives remain achieving high primary stability, maintaining a prosthetically driven implant position, and managing the gap between the implant and the socket walls with appropriate grafting procedures.

One important difference relates to immediate loading. Unlike the central incisor, where esthetic demands often justify immediate provisionalization, canine sites present a different challenge. Occlusal management can be significantly more difficult because of the functional role of the canine in lateral excursions.

For this reason, I will often place an anatomical healing abutment and allow the implant to heal without immediate loading.

Another characteristic of canine extraction sockets is their larger volume compared with central or lateral incisors. Consequently, these cases frequently require a greater amount of xenograft or regenerative material.

Maxillary Premolars

First Premolar

In the first premolar region, where two roots are frequently present, my implant of choice is typically the TLX 3.75 NT. Implant length is determined by the available apical bone and may vary between 8 mm, 10 mm, and 12 mm.

Second Premolar

The second premolar presents a different scenario. Because it usually has a single root, the extraction socket morphology is often wider and more cylindrical.

In these cases, I occasionally favor a wider implant, such as a 4.5 mm diameter implant. When apical bone is limited, primary stability is frequently obtained through engagement of the mesial and distal socket walls rather than through extensive apical anchorage.

I do not limit myself exclusively to the TLX NT configuration. Depending on the anatomy of the extraction socket, I may also use the TLX RT design. If the RT design allows better engagement of the available bone envelope, I will readily use it.

Maxillary First Molar

For maxillary first molars, my philosophy shifts toward wider implant diameters.

In most cases, I favor 4.5 mm implants, although I will occasionally use a 5.5 mm diameter implant when the socket morphology and available bone volume justify it.

Regarding implant length, I generally prefer shorter implants in this region, with 6 mm and 8 mm being my most commonly used lengths.

My implant selection is almost exclusively limited to BLX and TLX implants. Although I probably have a slight preference for the TLX concept in molar sites, my use is approximately balanced between TLX and BLX depending on anatomy and prosthetic requirements.

Mandibular Central and Lateral Incisors

The mandibular central and lateral incisors can essentially be considered a single clinical category.

The primary limitations are the buccal and lingual concavities that frequently characterize the anterior mandible and may restrict the amount of available apical bone.

Most of my implants in this region range from 2.9 mm to 3.5 mm in diameter.

When sufficient apical bone is available, I typically favor a BLX implant. When apical bone is more limited, I often shift toward a 3.3 mm BLT implant because of its tapered apical design.

In the most challenging situations, I may select a 2.9 mm implant. However, this is not my preferred solution due to the restorative limitations associated with these implants. Access to angled abutments and advanced prosthetic options may be limited.

Therefore, I generally try to avoid 2.9 mm implants whenever the anatomy permits the use of a wider implant.

Mandibular Canine

The mandibular canine is another indication where I do not have a particularly strong preference or a highly standardized immediate implant protocol.

Mandibular canine extractions requiring immediate implant placement are relatively uncommon in my practice. Whenever I encounter such a situation, I generally favor a delayed implant placement approach.

Unlike the maxillary canine, where immediate implant placement is often driven by aesthetic demands, the mandibular canine rarely presents the same level of urgency, making delayed implant placement an attractive and highly predictable alternative.

Mandibular Premolars

Mandibular premolars represent one of the most challenging indications for immediate implant placement.

Approximately 90% of my mandibular premolar implants are placed using a delayed protocol because the apex of the premolar root is often located only a few millimeters from either the inferior alveolar nerve or the mental foramen.

In the remaining cases where immediate implant placement is performed, I seek primary stability through engagement of the mesial and distal socket walls.

In these situations, I frequently favor a TLX implant in the 4.0 mm or 4.5 mm diameter range. The TLX 4.5 can be particularly effective because the tulip-shaped transmucosal portion contributes to engagement of the extraction socket anatomy when apical anchorage is limited.

Mandibular Molars

When discussing immediate implant placement in mandibular molars, the first question is not which implant to use, but whether the indication for immediate placement exists at all.

Adequate buccal bone preservation, absence of significant infection, and sufficient residual bone for primary stability are essential prerequisites.

When the indication is present, my preferred strategy is to place the implant within the interradicular septum between the mesial and distal roots.

If placing a 4.5 mm implant would require excessive removal of the septal bone, I often prefer a TLX RT 3.75 mm implant. The implant adapts well to the available septal anatomy, preserves more residual bone, and can achieve excellent primary stability.

I generally avoid placing implants in either the mesial or distal root sockets. The reason is primarily prosthetic. When implants are positioned in these locations, the emergence profile of the final restoration often becomes difficult to manage, particularly with tissue-level implants. Cleansability becomes compromised and long-term maintenance may be negatively affected.

For this reason, I consider the central septal position to be the ideal location whenever immediate implant placement is contemplated in a mandibular molar.

If the septum is absent and a central implant position cannot be achieved, I often ask a more fundamental question:

Does this case truly require immediate implant placement?

In many situations, a delayed protocol will ultimately provide a more predictable biological, prosthetic, and maintenance-friendly outcome.

Conclusions

Across all tooth positions, my decision-making process is not driven by a preference for a particular implant system, diameter, or connection type. Instead, it is guided by three fundamental principles:

1. Identifying where primary stability can be obtained.

2. Preserving the available anatomy.

3. Maintaining a prosthetically driven implant position.

Immediate implant placement should not be viewed as a surgical exercise but rather as a restorative solution that begins at the time of extraction.

The ideal implant is not necessarily the largest implant or the one that achieves the highest insertion torque. Instead, it is the implant that best balances biology, biomechanics, prosthetics, and long-term maintenance for a given clinical situation.

Key Take-Home Messages

1. Immediate implant placement is an indication, not an obligation.

2. Implant selection follows anatomy, not tooth position.

3. The source of primary stability changes according to the available anatomy.

4. Primary stability may come from apical anchorage, septal anchorage, mesial-distal engagement, or coronal/tulip engagement.

5. Preserve bone whenever possible; do not sacrifice anatomy for implant diameter.

6. Implant position is more important than implant size.

7. Prosthetic emergence profile should guide surgical decisions.

8. Long-term cleansability and maintenance are essential components of treatment planning.

9. If a prosthetically ideal position cannot be achieved, delayed implant placement should always be considered.

10. The best implant is not necessarily the easiest implant to place surgically, but the implant that provides the most predictable restorative outcome while respecting the available anatomy.