Nontraumatic Implant Explantation: A Biomechanical and Biological Analysis in Sheep Tibia

Alveolar Bone Reconstruction Simultaneous to Implant Removal due to Advanced Peri-Implantitis Defects: A Proof of Concept

OBJECTIVE

To evaluate the safety and effectiveness of alveolar bone reconstruction simultaneous to implant removal due to peri-implantitis.

MATERIAL AND METHODS

Partial or fully dentulous patients subjected to implant removal due to advanced peri-implantitis (≥ 50% of bone loss) lesions and seeking to have the failed implant replaced for esthetic or functional reasons were consecutively included. Guided bone regeneration was performed by means of a mixture of xenograft and autogenous bone and a ribose cross-linked barrier membrane. Re-entry for implant placement was performed at 4-month follow-up. Overall, six radiographic variables were assessed before (T0) and after (T1) alveolar bone reconstruction at four levels in ridge width (RW) and height (RH). Peri-implant conditions were evaluated at latest follow-up. Simple and multiple binary logistic regression models were calculated using generalized estimation equations to evaluate the effect of baseline upon reconstructive outcomes.

RESULTS

In total, 20 patients (n implant = 39) met the inclusion criteria. Alveolar RW and RH were augmented from T0 to T1 at all levels. All implants achieved primary stability. Only ~13% were subjected to ancillary bone regeneration simultaneous to implant placement. After a mean follow-up period after loading of ~2.2 years, ~70% implants demonstrated peri-implant health, while mucositis was diagnosed in the remaining implants.

CONCLUSION

The performance of alveolar bone reconstruction in residual partially contained defects simultaneous to implant removal due to peri-implantitis lesions demonstrates being safe and effective for implant site development.

Treatment strategies for dental implant removal: A literature review

Dental implants have been widely used with success, but long-term usage sometimes leads to implant loss. The purpose of this review was to summarize the etiology of early and late failure requiring dental implant removal and the treatment strategies for the removal of failed implants and reimplantation. Early failures are often caused by patient-related factors, such as smoking, diabetes, radiotherapy, bone quality, and periodontitis of the remaining natural teeth. The most common cause of late failure is peri-implantitis, followed by implant fracture and implant malpositioning. Implants should be removed if they are mobile or if their superstructure cannot be maintained (e.g., implant fracture). For peri-implantitis, implant removal should be determined based on the patient's age and esthetic needs, the implant site, and the severity of bone loss. Many reports have been published on implant removal techniques. The reverse torque technique should always be the first choice because of its low invasiveness. The weighted survival rate for the replacement of failed implants is 86.3%, with a much lower survival rate after the second or subsequent implantations. Therefore, patient-specific problems, such as smoking habits and bruxism, should be checked before reimplantation and controlled to the greatest extent possible.

Application of biologics for ridge preservation/reconstruction after implant removal

BACKGROUND

The purpose of this review was aimed at providing the rationale supported with a series of cases to apply biologics to enhance orchestrating the healing process at implant removal sites.

SUMMARY

Implant removal is commonly applied on a daily basis, in particular, in cases that exhibit esthetic failures linked to inadequate implant position or in cases of advanced peri-implantitis. Implant removal sites differ substantially from tooth extraction sockets. Implants are ankylosed within the alveolar bone, which therefore have neither mechanoreception nor the elasticity provided by periodontal ligament fibers. As a result, the bone-to-implant contact must be disrupted by means of using a reverse-torque device to minimize trauma. It is possible that the surrounding bone provides limited vascularity, which may interfere with the healing and bone forming process within the socket. Therefore, the use of biologics may enhance this healing and accelerate bone formation in sites where implants are removed due to hopeless functional or esthetic prognoses.

CONCLUSION

The use of biologics, in particular autologous blood-derived products, may enhance and boost the healing process to potentiate bone availability at a later stage during implant placement.

Management and sequelae of dental implant removal

Inappropriate and unnecessary implant therapy driven by an erroneous belief that dental implants provide enhanced function and esthetics over diseased or failing teeth has led to a growing burden of implant complications across the globe. Specifically, esthetic and biological complications frequently lead to the unfavorable prognosis of dental implants. Often, these cannot be managed predictably to improve the condition or satisfy patients' demands. In such circumstances, implant removal needs to be considered. Currently, minimally invasive methods based on reverse torque engineering are key to preserve peri-implant soft and hard tissues. Implant replacement is now feasible, as evidenced by the high survival rates of implants placed at previously failed sites. Notwithstanding these data, clinicians should still consider carefully the expendability of an implant and whether its replacement will satisfy the prosthetic, biomechanical, and esthetic demands of the patient. In the scenario where future implant placement is desired, protocols undertaken for soft/hard tissue grafting and implant placement should be based upon defect morphology and soft and hard-tissue characteristics. Currently, however, a lack of knowledge of the biological events and dimensional changes that arise following implant removal renders decision-making complex and challenging, and recommendations remain largely based upon empirical speculation. This chapter will review the indications for implant replacement for prosthetic, biomechanical, and esthetic complications, alongside considerations in decision-making, planning, implementation, and outcomes of implant replacement.

Factors influencing the removal torque of palatal implant used for orthodontic anchorage

Background

A non-invasive method has recently been introduced to remove osseo-integrated palatal implants by using the implantation ratchet which is designed to screw in or unscrew the implants. Although a proof of concept has been published, the torque involved to successfully explant have not been investigated so far. The aim of this study was to assess the removal torque required to explant osseo-integrated and orthodontically utilized palatal implants, and to identify potentially influencing variables.

Materials and method

Thirty-one consecutive patients (15 females, 16 males; mean age 24.1 ±7.4 years) with fully osseo-integrated and previously orthodontically loaded palatal implants (Orthosystem®: diameter 4.1mm/length 4.2mm/sandblasted with large grits (SLA) surface) were randomly assigned to either clockwise or counter-clockwise non-invasive explantation. The respective explantation tool with an electric torque control was placed on the abutment connection of the implant and secured by an occlusal screw.

The primary outcome studied was maximal removal torque (MRT) needed to detach the implant from its socket which was recorded individually together with other potentially influencing secondary outcomes (gender, age, orthodontic loading time, use of local anaesthetics). Student’s t-test was used to contrast MRT difference for the gender, type of suprastructure, use of local anaesthetics, and rotational direction.

Spearman correlations was used to investigate associations between MRT and patient’s age or duration loading time.

Results

Average MRT (148.6 ± 63.2N/cm) using ratchet as a non-invasive removal method of palatal implant was considered safe. The triangular head fractured of palatal implant at a torque level of 300.1 Ncm. Significantly higher explantation were recorded for male patients compared to female patients (182.0 ± 63.0 Ncm vs 112.8 ± 40.8 Ncm; P=0.001). On the other side, the mean removal torque for palatal removal in clockwise direction was non-significantly different (158.3 ± 58.6 Ncm) compared to counter-clockwise direction (139.4 ± 67.9 Ncm). Neither patient’s age (p=0.324) nor loading time (p=0.214) were significantly correlated with removal torque values.

Conclusions

Pertinent literature on this subject is practically non-existent, as orthodontics is presumably the only discipline where implant removal represents a treatment success. Mean MRT for successful palatal implant removal was 148.6±63.2Ncm, but a large spectrum was observed (minimum 31.5Ncm, maximum 272.8Ncm). This obvious heterogeneity underlines the importance to investigate possible influencing factors. The safe and simple non-invasive method for palatal implant removal necessitates moderate, but not high torque MRTs, independently of the torque direction. The necessary MRT seems clearly influenced by gender, but less so by patient’s age or loading time.

An alternative treatment for hopeless implants: Coronal resection

Dental implant surgery is a highly reliable therapy with widespread use all over the world. However, various accidental symptoms and complications such as peri-implantitis have been reported, and occasionally necessitate implant removal. This alternative technique was performed to minimize the harmful effect of conventional resective explantation procedures. The present case concerns a 55-year-old woman who had two dental implants in the mandibular incisor regions who apparently developed severe marginal peri-implantitis. Presence of lesion was confirmed by two and three-dimensional radiographic images. Explantation was indicated because of the excessive ongoing bone loss around implants. Due to avoid serious complications such as jaw fracture, coronal resection technique (partial explantation) was suggested. After the full thickness flap was elevated, affected part of both implants were resected, and osseointegrated healthy apical parts were left in the basal bone. Wound healing was uneventful at one week follow-up. Proper locater abutments were tightened after 5 months of the partial explantation procedure, and final denture was applied in the oral cavity. The radiologic and clinical examinations showed successful outcome at 12-months follow-up. Minimally resective peri-implantitis therapy may be achieved using this non-traumatic coronal implant resection approach.