Dr. Radhika Chheda, Dr.Pratik S. Chheda
Department of Prosthodontics and crown and bridge, MGM Dental College and Hospital, Navi Mumbai
Procare Dental Clinic
Dental implant success is attributed to the prosthetic success as well as surgical placement in 3- dimensionally accurate position. This becomes even more important if we need to place parallel implants. Sometimes, we encounter a situation wherein, an implant is already present in the patient’s mouth and there is a need to place adjacent dental implant parallel to it. It leads to surgical difficulties and requires a lot of expertise to achieve success in such situations. To overcome the difficulties and to ensure precision, a simplified technique to place parallel dental implant to existing one with the help of guided implant surgery has been described.
Keywords: Dental implant, digital dentistry, dental surgery, surgical guide, guided implant surgery
Citations: Chheda R, Cheddha P. A Novel Technique to place dental implant parallel to existing implant: A Case Report. J Prosthodont Dent Mater 2021;2(2):63-69.
The advent of digital guided surgeries and various software has made the process of dental implants very predictable and accurate. Accuracy in treatment planning and implementation of planned treatment is vital for this success.Severalsoftware systems are available for digital treatment planning and surgical template fabrication and significant updates and improvements have been made throughout the last 10 years. Virtual implant placement is performed on a computer, and the plan is then transferred to the patient using stereolithographic surgical guides that direct drill placement during surgery.
The use of these computer-assisted technologies is often restricted to the surgical aspects of implant treatment. Prosthetic treatment still has to be carried out following conventional protocols. However, the link to transfer prosthetic information to the patient is of great importance, and exact reference points are required to position the implants in such a way that prefabricated prosthetics have a precise fit. Sometimes we encounter a clinical scenario, wherein dental implants has to be placed adjacent to an existing implant. To simulate the parallelism in such cases poses a challenge. This leads to exposing the existing implant and determining its angle to simulate the angulation. Therefore, leads to increased bone loss and surgical complications. However, it may lead to certain misalignment. In such scenarios, angulated abutments, castableabutments or in severe cases even removable prosthesis have been suggested to surmount such complications.
However, with the digital technology, this minor malpositioning and surgical complexities can be avoided. This article aims to describe a method of placing dental implant parallel to the existing dental implant.
A 63-year-old male patient reported to Procare Dental Clinic and Implant Centre with mobility in tooth in the lower left side. On clinical examination, it was found that the lower first premolar was grade 2 mobile, second premolar was rotated and endodontically treated with a crown. There was a fixed prostheses with respect to 33-44. 36, 37 were replaced by implants, and healing abutments were placed. OPG revealed that there was re-infection with 35 and periodontal infection with 34. Osstem implants were placed with respect to 36, 37 two months back. It was decided to place an immediate implant in the 34 region and extract 35.
The implants in 34, 36 and 37 were planned to be splinted to distribute the forces evenly. In order to achieve this, parallelism between the 3 implants was one of the prerequisites. Therefore, a guided surgery was planned, wherein the dental implants were planned to be parallel to the previously placed implants.
A CBCT scan was done such that the already placed dental implant was seen clearly 3- dimensionally as seen in Figure 1. Also, the arch was scanned using intraoral scanner (3Shape TRIOS) as seen in Fig. 2. In the implant planning software (Implant Studio by 3Shape), both these scans were merged. Two implants were selected to be planned, one in the same place as the existing dental implant and the other in the desired position as shown in Fig. 3. An implant over the existing dental implant mimicking its position 3-dimensionally was planned as seen in Fig. 4.
The second implant was planned in the 34 region following the normal protocol.These planned dental implants were grouped such that it makes the second implant parallel to the first as seen in Fig. 5. The surgical guide was planned as seen in Figure 6. The teeth (34.35) were extracted using a periotome to ensure minimal trauma. Using the surgical guide, the dental implant was placed in the 34 region using the flapless guided surgery (Osstem) exactly parallel to the existing dental implant. IOPA was taken showing the parallel implants (Figure 7).
Fig 1: CBCT with already placed implants
Fig 2: Intraoral Scan of the arch with already placed implants and healing abutments.
Fig 3: Selection of two implants to be planned on Implant Studio
Fig 4: Planning of implant over already placed implant
Fig 5: Planning of second new implant and grouping them
Fig 7: IOPA showing three parallel implants
Initially, dental implants were planned according to the availability of bone. But as knowledge and technology improved, the focus of planning implants shifted from bone driven to prosthetic driven. A successful dental implant placement involves a position where the stress concentration is perpendicular and favorable. Unfavorable concentration of stress results in resorption of bone and eventually the failure of implant. Stress-induced damage to the bone attains undesirable proportions when more than one implant is splinted, especially when the implants are not placed in a mutually parallel position. Along with the biomechanical advantage of stress distribution, it also favors esthetics.Advancements in digital software for dental implants has made dental implants a predictable and accurate means. The use of technology to place dental implants parallel to each other improves the prosthetic success. It ensures passive fit and therefore longevity of the dental implant. In addition, the impression procedure and the various other steps in between also is simplified.
Parallel placement are ensured by various means like paralleling pins supplied with the kit, paralleling guide kits available separately. The use of stereolithographic surgical guides that direct drill placement has ensured better control over the positioning of dental implants. However, when dental implants already exist in a patient’s mouth, planning a new parallel dental implant adjacent to the existing ones becomes a challenge. It may be achieved by raising the flap and using pins on the previous ones but, this process would lead to extensive soft and hard tissue trauma. Therefore a novel minimally invasive technique to ensure a parallel implant in such situations has been devised.
This technique is a flapless procedure which ensures maximum patient comfort. It also prevents unnecessary raising of the flap of the already placed implant which prevents marginal bone loss and surgical complications. Therefore, the benefits of this simple technique is manifold.
The digital software in dentistry has made dental implants a predictable and accurate means of restoring missing teeth. This technique helps in placing a new dental implant precisely parallel to an existing implant using the implant planning software and surgical guide. Therefore, it enables better prosthetic outcome and survival of the dental implants by proper biomechanical advantage.
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