CBCT Evaluation for Risk Analysis in Implant Placement: A Retrospective and Validation Study

Peri-implantitis is a pathological condition marked by inflammation of the peri-implant soft tissues and progressive bone loss around dental implants. This condition is particularly concerning in anterior regions of the oral cavity, where the loss of soft tissue integrity can result in significant aesthetic, biological, and functional complications. Facial growth, especially in the anterior-posterior dimension, continues up to approximately 18 years of age; subtle but continuous remodelling affecting facial proportions may persist throughout adulthood as skeletal maturity progresses. This remodelling can negatively impact the long-term stability of implants placed at an early age. Negatively outcomes include implant infraposition, disharmony in the keratinized tissue relative to adjacent teeth, and increased risk of peri-implant bone loss. The objective of this retrospective study is threefold: (1) to analyze anterior-posterior skeletal changes in the maxillary and mandibular anterior regions over time using a dataset of 500 cone-beam computed tomography (CBCT) scans, with implants and natural teeth serving as anatomical reference points; (2) to quantify and compare longitudinal changes in buccal, lingual, and vertical bone dimensions in both anterior and posterior zones surrounding teeth and implants; and (3) to develop a predictive model for assessing the risk of implant-related complications and to inform future clinical guidelines for implant placement. This study utilizes CBCT imaging as an adjunct diagnostic tool to evaluate skeletal development, bone morphology, implant positioning, and associated risk factors for complications or failures. Data was collected from de-identified patient records at the College of Dentistry (COD), University of Illinois Chicago, spanning a 20-year period. The study received IRB exemption (IRB ID: STUDY2022-1465) from the Office for the Protection of Research Subjects (OPRS) at the COD and complies with institutional research protocol guidelines. A comprehensive keyword search of the COD AxiUm database identified patient records from May 1, 2001, to May 1, 2021. It contained documented implant complications, including peri-implantitis, peri-mucositis, implant failure, implant loss, bone loss, gingival recession, and implant-related inflammation. Extracted data included demographic and clinical variables such as age at the time of implant placement, sex, ASA classification, implant type and quantity, the necessity of hard/soft tissue grafting, type of prosthesis, and maintenance intervals. CBCT scans obtained prior to implant placement served as the baseline for evaluating changes in bone volume, with follow-up intervals determined by available clinical documentation. No patient identifiers were collected, nor were individuals contacted, and no new imaging was performed. Statistical analysis will involve multivariate and multidimensional linear regression models to identify predictive factors associated with anterior-posterior skeletal changes, implant site characteristics, patient demographics, and peri-implant or periodontal health outcomes. The findings aim to provide insight into long-term implant behavior in relation to skeletal growth and to support risk assessment protocols for future implant planning in both growing and skeletally mature patients. Of an initial pool of 500 CBCT scans, a total of 52 patients encompassing 125 dental implants met the inclusion criteria for analysis. Exclusions were primarily due to inadequate image quality, absence of baseline imaging, or insufficient follow-up duration. The average follow-up period was approximately 32 months. Implants were placed in both arches, with 63.5% in the maxilla and 36.5% in the mandible. No significant associations were found between implant location and patient sex or race. The mean patient age was 69.5 years, ranging from 18 to 80 years, with minor variations in age distribution across racial groups. Most participants were non-diabetic, although systemic conditions such as hypertension (42.3%) and a history of periodontitis (76%) were common. The majority of patients were non-smokers (77%) and non-drinkers (98.1%). Regarding implant and site characteristics, bicuspid regions were the most frequently treated sites (38.4%), followed by anterior (33.6%) and molar (28%) regions. The most commonly utilized implant systems were Nobel Biocare (Gothenburg, Sweden) and Straumann (Basel, Switzerland). Among grafting procedures, socket preservation significantly improved buccal and lingual bone thickness (p < 0.001), whereas guided bone regeneration (GBR) showed no statistically significant effect. Implant diameter showed a significant association with buccal bone thickness at the 1 mm level(p = 0.039). No significant associations were found at 3mm and 5mm. Quantitative CBCT analysis revealed that mean buccal bone loss from baseline (T1) ranged from 0.47 mm at the crestal level to 0.63 mm at a 5 mm depth. Palatal/lingual bone loss was similar, ranging from 0.58 mm at the crest to 0.54 mm at 5 mm. Coronal bone loss measurements showed average mesial and distal reductions of 2.37 mm and 2.44 mm, respectively. Notably, anterior-posterior skeletal changes did not demonstrate a significant influence on peri-implant bone loss patterns. Several clinical and radiographic factors were identified as influencing outcomes. Restoration type significantly impacted bone values measured via CBCT, particularly at the buccal 0–1 mm level and the lingual 5 mm levels. Mean probing depth (PD) was approximately 3.75 mm and remained consistent across buccal and lingual surfaces. Bleeding on probing (BOP) was observed in 53.3% of implants and was positively correlated with horizontal bone loss. Strong diagnostic correlations were observed among PD, CBCT measurements, and conventional two-dimensional (2D) radiographic data, thus supporting the reliability and consistency of multi-modal diagnostic approaches. Furthermore, BOP was strongly associated with the type of bone loss (horizontal vs. vertical), reinforcing its diagnostic utility. Risk factor analysis using a generalized linear model with generalized estimating equations (GLM-GEE) identified two significant predictors for peri-implantitis. Prior implant failure (odds ratio [OR] = 4.73, p = 0.007) and a history of periodontitis (OR = 3.35, p = 0.027) were both significantly associated with increased risk. Cross-tabulation revealed that peri-implantitis occurred in 83.3% of sites with prior implant failure and in 67% of those with a history of periodontitis. The corresponding odds ratios further emphasized the strength of these associations, at 5.00 and 6.68, respectively. In conclusion, this observational, retrospective CBCT-based analysis demonstrated that buccal and lingual bone loss occurs around dental implants over time. Socket preservation emerged as the only grafting intervention significantly associated with improved bone retention. While restoration type, implant diameter, and skeletal patterns showed localized effects on bone, a history of periodontitis and prior implant failure were the most robust predictors of peri-implantitis. Additionally, the strong correlation among CBCT, clinical probing depths, and 2D radiographs underscore the value of an integrated, multi-modal approach to peri-implant disease diagnosis and risk assessment.

Author dc:creator

• Amanda Beatriz Rodriguez Betancourt (24399011)

• Health Sciences
• Dentistry

Statement dc:rights

• In Copyright

DOI dc:identifier

https://doi.org/10.25417/uic.32991896.v1

OAI identifier oai:identifier

oai:figshare.com:article/32991896