1063 D3000 new imprint Word template Vol 13, No 1 (2025) ISSN 2167-8677 (online) DOI 10.5195/d3000.2025.1063 http://dentistry3000.pitt.edu Survival of Immediate-Loaded Pterygoid Implants with Multi-Unit Abutments in the Atrophic Posterior Maxilla Mohamad Droubi, Mazen Zena2 Faculty of Den.stry, Damascus University, Damascus, Syria Abstract Objec2ve: RehabilitaCon of the atrophic posterior maxilla is challenging due to insufficient bone quanCty and quality. ConvenConal approaches, such as sinus floor elevaCon or onlay bone graSing, are associated with higher morbidity, longer treatment Cmes, and increased complicaCons. Pterygoid implants offer a less invasive alternaCve, uClizing dense corCcal bone in the pterygoid apophysis and posterior maxillary tuberosity to provide distal anchor- age and full-arch prostheCc support, while avoiding the need for sinus augmentaCon. Clinical evidence indicates high survival rates, making them a reliable opCon for posterior maxillary rehabilitaCon. Materials and Methods: This prospecCve clinical study included 15 paCents (aged 49–78 years) with unilateral posterior maxillary tooth loss that was unsuitable for con- venConal implants. Each paCent received one pterygoid implant and two compressive im- plants. PreoperaCve planning included CBCT scans. Surgical procedures involved flap eleva- Con, precise drilling, and manual inserCon with high inserCon torque. Immediate prostheCc loading was performed within seven days. PostoperaCve care included anCbioCcs, analge- sics, chlorhexidine mouthwash, and oral hygiene instrucCons. Implant failure was defined as detectable mobility or condiCons requiring removal. Results: All 45 implants (15 pterygoid and 30 compressive) survived over the 12-month follow-up, with no failures observed at 3, 6, or 12 months. Survival rates were 100% for both implant types, and no differences were noted across follow-up periods. Conclu- sions: Pterygoid implants demonstrate high survival rates and represent a pre- dictable, minimally invasive opCon for posterior maxillary rehabilitaCon. Proper preoperaCve planning and surgical ex- perCse are essenCal, and further long- term studies are recommended to con- firm standardized protocols and durabil- ity. Open Access Cita%on: Droubi M, et al. (2025) Survival of Immediate- Loaded Pterygoid Implants with Mul%-Unit Abutments in the Atrophic Posterior Maxilla. Den%stry 3000. 1:a001 doi:10.5195/d3000.2025.1063 Received: October 3, 2025 Accepted: October 15, 2025 Published: November 4, 2025 Copyright: ©2025 Droubi M, et al. This is an open access ar%cle licensed under a Crea%ve Commons AVribu%on Work 4.0 United States License. Email: Mohamad.salah.droubi@gmail.com Introduc)on Rehabilitation of the atrophic posterior max- illa remains one of the most challenging cases of implant dentistry due to the amount and quality of bone that is missing in this lo- cation [1,2]. Conventional treatment strate- gies, such as onlay bone grafting or elevation of the sinus Aloor, have been widely utilized to circumvent these anatomical deAicits. Though these methods have been able to provide adequate bone volume to accommo- date implant placement, they are typically associated with increased surgical morbid- ity, higher treatment cost, longer treatment time, and a high incidence of intra- and post- operative complications, including sinus membrane perforation and graft resorption. Such drawbacks have prompted the develop- ment of alternative treatments that can by- pass the utilization of complex grafting pro- tocols [3]. Among such alternatives, the use of extra- maxillary anchorage, particularly zygomatic implants, has been the subject of signiAicant interest. Zygomatic implants have the ad- vantage of involving the engagement of the zygomatic bone, thereby offering stability in the presence of severe maxillary resorption [4,5]. However, the procedure is technically demanding, involves speciAic training, spe- cialized equipment, and has increased rates of complications such as sinusitis, paresthe- sia, or oroantral communication. Due to these limitations, pterygoid implants are a valuable and less invasive choice for poste- rior maxillary rehabilitation [6,7]. Pterygoid implants, Airst introduced some decades back, take advantage of the dense cortical bone of the pterygoid apophysis and posterior maxillary tuberosity. Their ana- tomical location provides space to place long implants that can provide excellent posterior Survival of Immediate-Loaded Pterygoid Implants with MulC-Unit Abutments in the Atrophic Posterior Maxilla Vol 13, No 1 (2025) DOI 10.5195/d3000.2025.1063 http://dentistry3000.pitt.edu 2 support, skipping sinus augmentation proce- dures altogether [8,9]. Moreover, they pro- vide for distal anchorage that allows for full- arch prosthetic rehabilitation even when se- verely atrophic maxillae are present. This singular biomechanical feature shortens cantilever lengths in prostheses and im- proves load distribution, possibly leading to better long-term results [10]. Clinical outcomes and survival rates of pter- ygoid implants have been examined by an in- creasing volume of literature over the last decade. Araujo et al. (2019), in arguably the most comprehensive systematic review to date, had a survival rate of 94.9% from pooled estimates of different clinical studies and demonstrated the stability of this treat- ment modality. Similarly, Bidra (2023) was at 95.5%, highlighting that pterygoid im- plants are capable of providing outcomes comparable with conventional implants placed in more favorable anatomical loca- tions. These results further support their role as a trustworthy treatment option [3,6]. Later studies have conAirmed these. D'Amario et al. (2024) and Raouf and Chrca- novic (2024) provided meta-analytic evi- dence of 97% to 99% survival, further sup- porting the role of pterygoid implants as a high-survival treatment. Their evaluations also revealed that survival outcomes are similar across different follow-up periods, though with slight discrepancies due to dif- ferences in study design, experience of oper- ators, and patient selection criteria [10,11]. On the other hand, future clinical evidence remains somewhat restricted. The early re- sults, as noted by Mirdah et al. (2025), were good in terms of early survival rates but also highlighted that anatomical challenge, bone quality, and factors related to the patient— oral hygiene compliance and health in gen- eral—still play a major role in long-term pre- dictability. This means that while pterygoid implants are predictable, they must be care- fully planned preoperatively, and technically skilled surgical capability must be employed in order to attain the best results [12]. Collectively, the literature has shown ptery- goid implants to be a reliable, minimally in- vasive option for sinus augmentation proce- dures during the rehabilitation of the atrophic posterior maxilla. Their survival rate is consistently reported to be greater than 94%, with many of these studies attain- ing or surpassing 97–99% [10,11]. These Aindings compare well with conventional im- plant therapy and highlight the potential of pterygoid implants to reduce treatment complexity, morbidity, and overall rehabili- tation time intervals. Nonetheless, disparity in success reported highlights the need for discerning patient selection, strict attention to particular surgical protocols, and follow- up over the long term. Subsequent investiga- tions with a focus on standardized surgical techniques, multicenter randomized con- trolled trials, and extended follow-up peri- ods will be signiAicant to establish conclusive results regarding their predictability and late outcome. This study aimed to evaluate the survival rates of pterygoid implants after immediate loading of single-piece pterygoid implants and multi-unit abutments in the posterior re- gion of the atrophic maxilla. Materials and Methods The study was designed as a prospective, single-group, interventional clinical study. The research sample consisted of 15 pa- tients, representing 15 cases, each with three implants: one pterygoid implant and two Compressive implants. The approval of the Ethics Committee at Da- mascus University was obtained under the number (DN-15042025-H25), and the study was registered in the (ISRCTN-BiomedCen- tral) database with the identiAier (ISRCTN77752182) and the link (https://www.isrctn.com/ISRCTN7775218 2). The research sample was selected from pa- tients attending the Oral and Maxillofacial Surgery clinic at Damascus University. These patients, aged between 49 and 78 years, had unilateral maxillary posterior dentition loss and were found to be unsuitable for conven- tional implant placement. The study was conducted in the dental im- plant clinic within the Department of Oral and Maxillofacial Surgery at the Faculty of Dentistry at Damascus University between 2022 and 2025. After informing the patients of the purpose and nature of the study in written and verbal form, ensuring their un- derstanding and answering their questions, written informed consent was obtained from the patients participating in the study. For the inclusion criteria, the patient had to have good oral health and a history of tooth loss in the premolar and molar regions of the maxilla. The height of the alveolar ridge be- tween the crest of the alveolar bone and the Aloor of the maxillary sinus should be less than 4 mm, with a vestibular bone width in the premolar region greater than 4 mm. The inferior angle of the anterior wall of the max- illary sinus must be anterior to the second premolar. Additionally, the last extraction in the included area must have occurred more than two months ago, and there should be sufAicient occlusal space for prostheses. The patient's consent was obtained after a full ex- planation of the research procedures. For the exclusion criteria, patients with any metabolic diseases affecting normal bone metabolism, such as hyperparathyroidism or osteoporosis were not included. Patients with bruxism should be excluded. Also, no patients on medications that caused bone metabolism disorders, such as corticoster- oids, hormonal treatments, or chemother- apy, and patients receiving radiation therapy to the face or neck were not included. Finally, patients that had any contraindications to implants due to systemic diseases such as leukemia or coagulation disorders were not included. A CBCT scan was performed before begin- ning the surgery. This was to verify measure- ments and dimensions, ensuring accurate planning of the surgical procedure. The mouth was disinfected using a 0.12% chlorhexidine rinse, and the perioral skin was cleaned with a polyvidone iodine solu- tion. Local inAiltration anesthesia was admin- istered using Lidocaine 2% with Adrenaline (1:80,000) in the premolar and maxillary ca- nine regions, where the Compressive im- plant would be placed. Nerve block anesthe- sia was then performed using Lidocaine 2% with Adrenaline (1:80,000) in the tuberosity region, where the pterygoid implant would be located. A full-thickness vestibular mucoperiosteal envelope Alap was created to minimize heal- ing time. The Alap was carefully elevated while preserving the periosteum, ensuring an optimal healing process. After exposing the alveolar bone, the im- plants’ sites were prepared according to the protocol followed in this study: two com- pressive implants. Roott m implants ranged in length from 8-12 mm and diameters from 3.5-4 mm, and Roott p implants were placed in the posterior maxillary sinus area with the implant tilted at an angle ranging from 15- 45°. Implant diameters range from 3.5 to 4.5 mm and lengths from 18-20 mm. For compressive implants, the initial drill was used to drill the cortical bone. Then, we moved on to a pilot drill with a diameter of 2 mm. This completed the preparation for im- plants with a diameter less than 4 mm. For implants with a diameter of 4 mm, we pre- pared a second drill with a diameter of 2.5 mm. The implant was then inserted manu- ally with the implant insertion tool, ensuring that the insertion torque is 35 N cm. For pterygoid implants, we began with a hand drill to determine the desired angle of drilling. We then moved on to a 2 mm pilot drill, completing the preparation for 3.5 mm implants. For 4.5 mm implants, we prepared a second 2.5 mm drill, the implant was then inserted using an implant insertion tool, en- suring that the insertion torque is greater than 35 N cm. After the three implants were inserted with an insertion torque greater than 35 N cm, the gingival Alap was then repositioned and Survival of Immediate-Loaded Pterygoid Implants with MulC-Unit Abutments in the Atrophic Posterior Maxilla Vol 13, No 1 (2025) DOI 10.5195/d3000.2025.1063 http://dentistry3000.pitt.edu 3 sutured around the abutments. The implant transfer was then placed, and impressions were taken using rubber. The impressions were sent to the lab for prosthetics (ceramic on metal). The healing abutments were then placed on the multi-unit abutments. The patient was advised to avoid rinsing the mouth on the Airst day following surgery. Cold compresses could be applied to the cheek on the surgical site immediately after the procedure, alternating every 4 hours for the Airst few hours. An analgesic might be taken if necessary to manage pain. Oral hygiene procedures were suggested to begin the day after surgery. The patient was prescribed the following medications: amox- icillin 875 mg + clavulanic acid 125 mg every 12 hours, and diclofenac potassium 50 mg as needed for pain, not to exceed 150 mg per day. Additionally, a 0.12% chlorhexidine mouthwash should be used twice daily (for 60 seconds) for 7 days, starting the day after surgery. After completing suturing, the implant abut- ments were placed, and an impression was immediately taken using a condensation sili- cone material in a single stage. The following day, a veriAication jig was prepared by at- taching the implant abutments to the stone model using pattern resin, and the jig was tested in the patient's mouth to verify the ac- curacy of the impression. Next, the metal framework for the restoration was designed and 3D-printed using laser technology. The metal framework was then tried in to ensure it Aits accurately onto the abutments and the gingiva. The bridge was then veneered with- out glazing and tried again to adjust the oc- clusion, ensuring that each tooth has 3 to 4 contact points without any premature con- tacts, and that the restoration was in proper contact with the gingiva. Finally, the restora- tion was glazed and Aixed with screws tight- ened to 15 N cm, according to the manufac- turer's instructions. The screw holes were sealed with composite material, and a TeAlon barrier was placed. All prosthetic steps were completed within seven days of surgery. Failure was deAined as the presence of any detectable mobility of the implant and/or any condition requiring implant removal. The implants were followed up for one year after immediate loading. Results The study sample included 15 patients, with 15 wing implants and 30 compressive im- plants. The mean age was 60.07 years, with 8 males and 7 females. The frequencies of implant survival and fail- ure were calculated for the studied implants across the three follow-up periods. The re- sults are summarized in Table 1. As shown in Table 1, no implant failures were observed among the studied implants at any of the follow-up periods. All applied and studied implants remained fully re- tained throughout the observation period. Consequently, there were no differences in implant survival/failure rates across follow- up periods, and therefore, the application of the Wilcoxon test to compare survival/fail- ure between follow-up stages was not war- ranted. Discussion The present study demonstrated a 100% survival rate for pterygoid implants, which is remarkably high compared to most out- comes reported in the literature. Over the past decade, numerous clinical studies and systematic reviews have evaluated the long- term performance of pterygoid implants, generally showing favorable but slightly lower success rates. For example, Bidra (2023) [6] conducted a systematic review and reported a cumulative survival of 95.5% over six years, emphasizing that pterygoid implants provide a reliable alternative to zy- gomatic implants in atrophic maxillae. Simi- larly, Araujo et al. (2019) [3], in one of the largest systematic reviews including nearly 1,900 implants, found a survival rate of 94.9%. These Aindings reinforce the concept that pterygoid implants are a predictable treatment modality, though outcomes vary slightly among different cohorts and follow- up durations. Meta-analytical data also corroborate these results. D’Amario et al. (2024) [11] analyzed 1,882 implants across 1,024 patients and re- ported a survival rate of 97.4%, further sup- porting the long-term reliability of pterygoid implants. Raouf and Chrcanovic (2024) [10] conducted a systematic review comparing pterygoid and tuberosity implants, reporting similar survival outcomes between the two techniques, thereby highlighting the clinical versatility of posterior maxillary anchorage solutions. Retrospective series, such as the one by Curi et al. (2015) [13], found 99% sur- vival over three years, suggesting that these implants consistently yield excellent results across different populations and clinical set- tings. On the other hand, prospective studies sometimes demonstrate slightly lower sur- vival rates. For instance, Mirdah et al. (2025) [12] reported 88.6% survival at one year, noting that early failures were often related to anatomical limitations and bone quality rather than prosthetic complications. These Aindings emphasize the importance of case selection and meticulous surgical planning, as the anatomical complexity of the ptery- goid region can inAluence outcomes. Simi- larly, Signorini et al. (2021) [14] reported favorable survival rates in a short-term fol- low-up, but highlighted the need for longer longitudinal studies to fully assess long-term predictability. When comparing these Aindings to the pre- sent study, the observed 100% survival rate indicates that under controlled clinical con- ditions, with proper patient selection, careful preoperative planning, and precise surgical execution, pterygoid implants can achieve survival rates equal to or even higher than those previously reported. Differences in outcomes may be attributed to multiple fac- tors, including study design (retrospective versus prospective), sample size, operator experience, and follow-up duration. Addi- tionally, the prosthetic protocols adopted— such as immediate loading versus delayed loading—may also play a role in inAluencing success rates. The superior outcomes in the present study may also reAlect advancements in imaging modalities, such as cone-beam computed to- mography (CBCT), which enhance preopera- tive assessment and reduce the risk of surgi- cal complications. Furthermore, the use of new implant designs may have contributed to the high survival rate observed. These Aindings align with the broader body of liter- ature afAirming the predictability of ptery- goid implants but suggest that under opti- mized conditions, survival can approach 100% [7,15]. Taken together, these results underscore the clinical reliability of pterygoid implants as a viable option for the rehabilitation of the atrophic posterior maxilla. They not only provide a predictable survival rate but also reduce the need for more invasive proce- dures such as sinus grafting or zygomatic im- plant placement. Future studies, particularly long-term multicenter prospective trials, are necessary to validate these Aindings across diverse patient populations and clinical con- texts. Conclusion Within the limitations of this study, ptery- goid implants demonstrated high survival rates and represented a predictable, mini- mally invasive alternative for posterior max- illary rehabilitation. Current evidence sup- ports their reliability, yet further long-term prospective studies are warranted to estab- lish standardized protocols and confirm their long-term clinical performance. Funding None. Data Availability The authors can provide data on demand. Compe)ng Interests None. Survival of Immediate-Loaded Pterygoid Implants with MulC-Unit Abutments in the Atrophic Posterior Maxilla Vol 13, No 1 (2025) DOI 10.5195/d3000.2025.1063 http://dentistry3000.pitt.edu 4 References 1. Candel-Martı ́ E, Carrillo-Garcıá C, Peñarrocha-Oltra D, Peñarrocha-Diago M. 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Signorini L, Faustini F, Samarani R, Grandi T. Immediate lixed rehabilitation supported by pterygoid implants for participants with severe maxillary atrophy: 1-Year postloading results from a prospective cohort study. The Journal of Prosthetic Dentistry. 2021;126(1):67- 75. 15. Rastelli S, Capogreco M, D'Amario M, Falisi G, Severino M, Iacomino E. Pterigoid implants: A viable alternative for the rehabilitation of the posterior sectors of the atrophic maxilla. Oral & Implantology. 2024;16(1). Table 1. Percentage of implant survival/failure across three follow-up periods. Implant Outcome Implant Type 3 Months 6 Months 12 Months 3 Months (%) 6 Months (%) 12 Months (%) Survival Pterygoid 15 15 15 100% 100% 100% Survival Conventional 1 15 15 15 100% 100% 100% Survival Conventional 2 15 15 15 100% 100% 100% Failure Pterygoid 0 0 0 0% 0% 0% Failure Conventional 1 0 0 0 0% 0% 0% Failure Conventional 2 0 0 0 0% 0% 0% Total – 45 45 45 100% 100% 100%