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Research Article | DOI: https://doi.org/10.31579/2690-1919/410
1Associate Professor in fixed prosthodontic Faculty of Dentistry, Thamar University, Yemen.
2MDSE. Faculty of Dentistry Sana’a University – Yemen.
3Dean of Faculty of Dentistry on 21 September University, Yemen, Head of Restorative and Esthetic Dentistry, Dental Implant Consultant.
4Professor in operative dentistry Faculty of Dentistry - Sana’a University.
*Corresponding Author: Abdulwahab Ismail Al-kholani,Dean of Faculty of Dentistry on 21 September University, Yemen, Head of Restorative and Esthetic Dentistry, Dental Implant Consultant.
Citation: Mohsen Ali Al-Hamzi, Samah Nabil Al-Hammadi, Abdulwahab Ismail Al-kholani, Ibrahim Zaid Al-Shami, (2024), Evaluation of Failure Factors of Fixed Prosthesis in a Sample of Yemeni Dental Patients - Sana'a City, J Clinical Research and Reports, 16(5); DOI:10.31579/2690-1919/410
Copyright: © 2024, Abdulwahab Ismail Al-Kholani. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Received: 18 September 2024 | Accepted: 27 September 2024 | Published: 08 October 2024
Keywords: fpds; fixed partial denture failures; crown and bridge failures
Tooth loss is a prevalent global health issue. The World Health Organization (WHO) estimates that nearly 7% of individuals aged 20 or older have complete tooth loss, increasing to 23% for those aged 60 or older. Fixed partial dentures (FPDs) are a common restorative option but often face failure.
Aim: This study investigated factors contributing to FPD failure in Yemeni patients.
Methods: A cross-sectional study was conducted on 208 FPD failure cases from 117 patients. Clinical examination, periodontal probing, and radiographic assessment were performed. Data on biological, mechanical, and aesthetic failures were collected.
Results: Biological factors accounted for 75% of failures, followed by aesthetic (18%) and mechanical (7%). The primary biological contributors were poor oral hygiene, periodontal problems, and food impaction. The most common mechanical failures were prosthesis fractures and dislodgements. Shade mismatch was the primary aesthetic issue.
Conclusion: FPD failures in Yemeni patients were primarily attributed to biological factors, emphasizing the importance of oral hygiene and periodontal health maintenance. Addressing these factors is crucial for the long-term success of FPDs
Teeth serve vital functions in daily life, including chewing, communication, and facial aesthetics. Tooth loss, a common global issue, primarily stems from untreated caries and periodontal disease, but can also result from trauma or congenital absence. To address this, fixed partial dentures (FPDs) are frequently used to replace missing teeth.
FPDs can significantly improve a patient's quality of life by restoring function and aesthetics. However, their success depends on various factors, including patient care, clinician expertise, and prosthesis quality. Biological, mechanical, and aesthetic complications can lead to FPD failure, impacting patient satisfaction and overall oral health.
While FPDs offer a promising solution for tooth loss, understanding the factors that contribute to their failure is essential for optimizing treatment outcomes and ensuring long-term patient well-being. This study aimed to investigate the prevalence and types of FPD failures in a Yemeni population.
Study Design
This cross-sectional clinical study was conducted between June 2020 and August 2022 at the Departments of Conservative Dentistry in the Faculty of Dentistry, Sana'a University and the University of Science and Technology, Sana'a, Yemen.
Study Site and Population
Participants were recruited from patients attending the polyclinics of the Faculty of Dentistry and the University of Science and Technology. All subjects were adults, regardless of gender.
Sample Size Calculation
A sample size of 208 fixed partial dentures (FPDs) was calculated using the following formula:
n = (z^2 * p̂ * (1 - p̂)) / ε^2
Where:
• n is the desired sample size
• z is the number of standard deviations (1.44 for an 85% confidence level)
• p̂ is the estimated proportion of the outcome in the target population (set at 50% for a maximum estimate of FPD prevalence in the Yemeni population)
• ε is the maximum size of the standard error (set at 5%)
Sampling Method
Randomized sampling was employed to select Yemeni dental patients attending the Faculty of Dentistry, Sana'a University, and the University of Science and Technology.
Inclusion Criteria
• Subjects must be adults aged 18-50 years.
• Subjects must have crowns or bridges.
Exclusion Criteria
• Medically compromised conditions.
• Complete edentulous patients.
• Pregnant women.
• Individuals over 50 years old.
Study Methods
Patient Selection: Patients who met the inclusion criteria and did not have any exclusion criteria were included in the study.
Data Collection:
• Case Sheet: A standardized case sheet was used to collect patient information, including medical and dental history, intraoral examination findings, and information about the fixed prosthesis.
• Examination Instruments: Mirror, tweezer, explorer, periodontal probe, and dental x-rays (periapical or panoramic) were used for clinical examination.
• Data Collection Procedure: Patients attending dental clinics were examined clinically for fixed prostheses. A detailed case sheet was completed for patients with issues related to their crowns or FPDs.
• Failure Factors: Biological, mechanical, and aesthetic factors were assessed. Biological factors included periapical lesions, gingivitis, periodontitis, secondary caries, mobility, poor oral hygiene, bone resorption, and abscess formation. Mechanical factors included dislodged prosthesis, fracture of an abutment, prosthesis fracture, traumatic occlusal force, and loss of restoration along with abutment teeth. Aesthetic factors included shade mismatch and contour discrepancies.
Statistical Analysis: Descriptive statistics, including mean, standard deviation, and percentages, were used to analyze the collected data.
Note: The specific examination methods for each failure factor have been provided in Table 1.
Table 1: The Examination Methods of Fixed Prosthesis Failure Factors
| Cause | Examination Method |
| Periapical lesion | Periapical x-ray |
| Gingivitis | Bleeding on probing |
| Periodontitis | Pocket depth |
| Secondary caries | Probing on the margin of restoration |
| Mobility | Degree of Horizontal mobility |
| Poor oral hygiene | Brushing and plaque accumulation |
| Bone resorption | Periapical x-ray |
| Pain and swelling | Patient history |
| Abscess formation | By vision and patient history |
| Shade mismatch and Contour discrepancies | By vision |
| Fracture of an abutment | Periapical x-ray |
| Prosthesis fracture | By vision |
A total of 208 fixed partial dentures (FPDs) were analyzed from 117 participants (89 females and 28 males, mean age: 35.76 ± 8.06 years). Participants' demographic characteristics and academic levels are summarized in (Tables 2&3&4)
Table 2: Demographic information of the study participants
Table 3: The mean age of the study participants
Table 4: The academic level of the study participants
| Academic Level | Female (n = 89) | Male (n = 28) | Total (n = 117) |
| Illiterate | 44 | 2 | 46 |
| Primary | 47 | 8 | 55 |
| Middle | 13 | 3 | 16 |
| High | 19 | 9 | 28 |
| College | 39 | 24 | 63 |
FPD Characteristics
• Age: 56% of FPDs were at least five years old, followed by 30% aged two to four years, and 14% less than one year.
• Material: All the studied FPDs were PFM. It has been not found that FPDs made of all ceramic, all metal, or any other materials.
• Position: 106 FPDs were in the upper arch, while 102 were in the lower arch.
• Location: 70% of FPDs were posterior, 16% anteroposterior, and 14% anterior.
• Units: 30% of FPDs had one unit, 30% had three, 22% had two, and 18% had at least four units.
Material used
| Material of Prosthesis | No. of cases (n = 208) | Percentage % |
| PFM | 208 | 100% |
| All ceramic | 0 | 0% |
| All metal | 0 | 0% |
| Others | 0 | 0% |
Table 5: Material of Prosthesis
As seen in Table 5, all of the fixed partial dentures (FPDs) analyzed in the study were made of porcelain-fused-to-metal (PFM). No other materials, such as all ceramic or all metal, were found in the sample. This indicates that PFM is the predominant material used for FPDs in the Yemeni population studied.
The Relationship Between Failure Factors and Various Variables
The study examined the relationship between FPD failure and several factors, including age, academic level, brushing frequency, prosthesis age, position, location, and number of units. The findings are summarized in Tables 6-13.
This table provides an overview of the most common failure factors, with poor oral hygiene, periodontal problems, shade mismatch, and food impaction being the primary contributors.
| Failure Factors | Percentage % |
| Poor oral hygiene | 19% |
| Periodontal problem (gingivitis/periodontitis) | 17% |
| Shade mismatch | 15% |
| Food impaction | 13.3% |
| Secondary caries | 12.7% |
| Pain | 6% |
| Periapical lesion | 5% |
| Prosthesis fracture | 4% |
| Contour discrepancies | 3% |
| Dislodged prosthesis | 2% |
| Mobility | 1% |
| Abscess formation | 1% |
| Fracture of an abutment | 0.6% |
| Swelling | 0.4% |
| Loss of restoration along with abutment teeth | 0% |
Table 6: Prevalence of Failure Factors
Prevalence of Failure Factors in Descending Order
• Younger patients (≤34 years old): More likely to experience mechanical failures like dislodged prosthesis and prosthesis fracture.
• Older patients (>34 years old): More likely to experience biological failures like periodontal problems, food impaction, and poor oral hygiene.
| Type of Failure | Failure Factors | ≤ 34 years old | > 34 years old |
| Biological failure | Periodontal problem (gingivitis/periodontitis) | 53 (28%) | 82 (20%) |
| Food impaction | 28 (15%) | 76 (19%) | |
| Poor oral hygiene | 44 (24%) | 100 (24%) | |
| Mobility | 0 (0%) | 8 (2%) | |
| Periapical lesion | 13 (7%) | 28 (7%) | |
| Secondary caries | 27 (14%) | 76 (19%) | |
| Bone resorption | 0 (0%) | 3 (0.9%) | |
| Pain | 16 (9%) | 31 (7%) | |
| Swelling | 0 (0%) | 1 (0.2%) | |
| Abscess formation | 5 (3%) | 3 (0.9%) | |
| Mechanical failure | Dislodged prosthesis | 11 (55%) | 6 (19%) |
| Fracture of an abutment | 1 (5%) | 2 (7%) | |
| Prosthesis fracture | 8 (40%) | 23 (74%) | |
| Loss of restoration along with abutment teeth | 0 (0%) | 0 (0%) | |
| Esthetic failure | Shade mismatch | 38 (83%) | 80 (82%) |
| Contour discrepancies | 8 (17%) | 18 (18%) | |
| Total | 32% | 68% |
Failure Factors Concerning Age
Table 7: Failure Factors Concerning Age
• Lower education levels (illiterate, primary): Higher rates of periodontal problems, food impaction, and poor oral hygiene.
• Higher education levels (college): Higher rates of shade mismatch and contour discrepancies.
| Failure Factors | Illiterate | Primary | Middle | High | College |
| Periodontal problem | 29 (15%) | 32 (13.5%) | 12 (23%) | 22 (21%) | 39 (20%) |
| Food impaction | 28 (14%) | 31 (13%) | 7 (14%) | 11 (11%) | 29 (14.5%) |
| Poor oral hygiene | 38 (20%) | 46 (19%) | 12 (23%) | 17 (16%) | 28 (14%) |
| Mobility | 5 (2%) | 3 (1%) | 0 (0%) | 0 (0%) | 0 (0%) |
| Periapical lesion | 12 (6%) | 11 (5%) | 1 (2%) | 2 (2%) | 15 (7%) |
| Secondary caries | 25 (13%) | 32 (13.5%) | 8 (15%) | 16 (16%) | 22 (11%) |
| Bone resorption | 0 (0%) | 2 (1%) | 0 (0%) | 1 (1%) | 1 (0.5%) |
| Pain | 9 (5%) | 19 (8%) | 2 (4%) | 5 (5%) | 11 (5%) |
| Swelling | 1 (1%) | 0 (0%) | 0 (0%) | 0 (0%) | 0 (0%) |
| Abscess formation | 3 (2%) | 2 (1%) | 0 (0%) | 0 (0%) | 3 (1.5%) |
| Dislodged prosthesis | 5 (2%) | 2 (1%) | 0 (0%) | 2 (2%) | 8 (4%) |
| Fracture of an abutment | 0 (0%) | 1 (0.5%) | 0 (0%) | 0 (0%) | 2 (1%) |
| Prosthesis fracture | 5 (2%) | 15 (6.5%) | 1 (2%) | 6 (6%) | 5 (2.5%) |
| Shade mismatch | 29 (15%) | 30 (13%) | 8 (15%) | 15 (15%) | 35 (17%) |
| Contour discrepancies | 6 (3%) | 10 (4%) | 1 (2%) | 5 (5%) | 4 (2%) |
| Total | 195 (25%) | 236 (30%) | 52 (6.5%) | 102 (13%) | 202 (25.5%) |
Table 8: Failure Factors Concerning Academic Level
Failure Factors Concerning Academic Level
• Lack of brushing: Significantly higher rates of all failure factors.
• Consistent brushing: Lower rates of failure factors.
| Failure Factors | Once | Twice | Three times | No brushing |
| Periodontal problem | 41 (16%) | 7 (24%) | 0 (%) | 85 (16%) |
| Food impaction | 34 (13%) | 4 (13%) | 0 (%) | 65 (12%) |
| Poor oral hygiene | 34 (13%) | 2 (7%) | 0 (%) | 111 (20.5%) |
| Mobility | 3 (1%) | 0 (0%) | 0 (%) | 5 (1%) |
| Periapical lesion | 13 (5%) | 2 (7%) | 0 (%) | 27 (5%) |
| Secondary caries | 25 (9.5%) | 1 (3%) | 0 (%) | 76 (14%) |
| Bone resorption | 1 (0.5%) | 0 (0%) | 0 (%) | 3 (0.5%) |
| Pain | 16 (6%) | 3 (10%) | 0 (%) | 28 (5%) |
| Swelling | 0 (0%) | 0 (0%) | 0 (%) | 1 (0.2%) |
| Abscess formation | 2 (1%) | 1 (3%) | 0 (%) | 5 (1%) |
| Dislodged prosthesis | 5 (2%) | 1 (3%) | 0 (%) | 11 (2%) |
| Fracture of an abutment | 7 (3%) | 1 (3%) | 0 (%) | 2 (0.3%) |
| Prosthesis fracture | 35 (14%) | 0(0%) | 0 (%) | 25 (5%) |
| Shade mismatch | 35 (14%) | 7 (24%) | 0 (%) | 77 (14%) |
| Contour discrepancies | 6 (2%) | 1 (3%) | 0 (%) | 19 (3.5%) |
| Total | 257 (30.5%) | 30 (3.5%) | 0 (0%) | 551 (66%) |
Failure Factors Concerning Brushing Frequency
Table 9: Failure Factors Concerning Brushing Frequency
• Newer prostheses (≤2-4 years): Higher rates of periodontal problems, food impaction, and poor oral hygiene.
• Older prostheses (≥5 years): Higher rates of shade mismatch and contour discrepancies.
| Failure Factors | ≥ 1 year | 2-4 years | ≤ 5 years |
| Periodontal problem | 16 (18.5%) | 43 (19%) | 74 (16%) |
| Food impaction | 10 (11.5%) | 29 (13%) | 64 (13.5%) |
| Poor oral hygiene | 17 (19.5%) | 44 (19%) | 86 (18%) |
| Mobility | 0 (0%) | 1 (0.5%) | 7 (1.5%) |
| Periapical lesion | 2 (2%) | 14 (6%) | 26 (5.5%) |
| Secondary caries | 3 (3.5%) |
Failure Factors Concerning the Age of the Prosthesis
Table 10: Failure Factors Concerning the Age of the Prosthesis
• Lower prostheses: Slightly higher rates of periodontal problems, food impaction, and poor oral hygiene compared to upper prostheses.
| Failure Factors | Upper | Lower |
| Periodontal problem (gingivitis/periodontitis) | 69 (18%) | 63 (15.5%) |
| Food impaction | 49 (13%) | 54 (13%) |
| Poor oral hygiene | 75 (19.3%) | 72 (18%) |
| Mobility | 3 (0.7%) | 5 (1%) |
| Periapical lesion | 13 (3.3%) | 28 (7%) |
| Secondary caries | 56 (14.5%) | 47 (12%) |
| Bone resorption | 0 (0%) | 4 (1%) |
| Pain | 17 (4%) | 31 (8%) |
| Swelling | 1 (0.2%) | 0 (0%) |
| Abscess formation | 4 (1%) | 4 (1%) |
| Dislodged prosthesis | 9 (2.5%) | 8 (2%) |
| Fracture of an abutment | 3 (0.7%) | 0 (0%) |
| Prosthesis fracture | 15 (4%) | 16 (4%) |
| Shade mismatch | 56 (14.5%) | 63 (15.5%) |
| Contour discrepancies | 17 (4.3%) | 9 (2%) |
| Total | 387 (49%) | 404 (51%) |
Failure Factors Concerning the Position of the Prosthesis
Table 11: Failure Factors Concerning the Position of the Prosthesis
• Posterior prostheses: Significantly higher rates of failure compared to anterior or anteroposterior prostheses.
| Failure Factors | Anterior | Posterior | Anteroposterior |
| Periodontal problem | 19 (18%) | 96 (18%) | 19 (13%) |
| Food impaction | 9 (8.3%) | 73 (13.5%) | 21 (14.5%) |
| Poor oral hygiene | 22 (20.2%) | 97 (18%) | 28 (19.5%) |
| Mobility | 3 (2.5%) | 4 (0.5%) | 1 (0.5%) |
| Periapical lesion | 3 (2.5%) | 30 (5.5%) | 9 (6.5%) |
| Secondary caries | 16 (15%) | 66 (12%) | 20 (14%) |
| Bone resorption | 0 (0%) | 3 (0.5%) | 1 (0.5%) |
| Pain | 3 (2.5%) | 36 (6.8%) | 9 (6.5%) |
| Swelling | 1 (1%) | 0 (0%) | 0 (0%) |
| Abscess formation | 2 (2%) | 4 (0.5%) | 2 (1.5%) |
| Dislodged prosthesis | 3 (2.5%) | 11 (2%) | 3 (2%) |
| Fracture of an abutment | 0 (0%) | 1 (0.2%) | 2 (1.5%) |
| Prosthesis fracture | 4 (4%) | 22 (4%) | 6 (4%) |
| Shade mismatch | 16 (15%) | 84 (15.5%) | 18 (12.5%) |
| Contour discrepancies | 7 (6.5%) | 15 (3%) | 5 (3.5%) |
| Total | 108 (14%) | 542 (68%) | 144 (18%) |
Failure Factors Concerning the Number of Units
Table 12: Failure Factors Concerning the Location of the Prosthesis
• 3-unit prostheses: Highest rates of failure, primarily due to periodontal problems, food impaction, and poor oral hygiene.
| Failure Factors | 1 unit | 2 units | 3 units | ≤ 4 units |
| Periodontal problem | 38 (17%) | 32 (17.5%) | 41 (17%) | 23 (15.5%) |
| Food impaction | 33 (14.5%) | 23 (13%) | 25 (10.5%) | 23 (15.5%) |
| Poor oral hygiene | 38 (17%) | 34 (19%) | 44 (18.5%) | 31 (20.5%) |
| Mobility | 2 (1%) | 2 (1%) | 3 (1%) | 1 (0.5%) |
| Periapical lesion | 13 (6%) | 11 (6%) | 9 (4%) | 8 (5.5%) |
| Secondary caries | 29 (13%) | 25 (14%) | 27 (11%) | 23 (15.5%) |
| Bone resorption | 1 (0.5%) | 2 (1%) | 0 (0%) | 1 (0.5%) |
| Pain | 11 (5%) | 9 (5%) | 20 (8.5%) | 8 (5.5%) |
| Swelling | 0 (0%) | 0 (0%) | 1 (0.5%) | 0 (0%) |
| Abscess formation | 1 (0.5%) | 1 (0.5%) | 5 (2%) | 0 (0%) |
| Dislodged prosthesis | 4 (2%) | 3 (1.5%) | 6 (2.5%) | 4 (2.5%) |
| Fracture of an abutment | 2 (1%) | 0 (0%) | 1 (0.5%) | 0 (0%) |
| Prosthesis fracture | 6 (2.5%) | 6 (3%) | 13 (5.5%) | 9 (6%) |
| Shade mismatch | 41 (18%) | 28 (15.5%) | 33 (14%) | 15 (10%) |
| Contour discrepancies | 5 (2%) | 6 (3%) | 10 (4.5%) | 4 (2.5%) |
| Total | 224(26.5%) | 182(21.5%) | 283 (34%) | 150 (18%) |
Failure Factors Concerning the Number of Units
Table 13: Failure Factors Concerning the Number of Units
Overall Analysis: The study found that biological factors, such as poor oral hygiene and periodontal disease, were the primary contributors to FPD failure. However, mechanical and aesthetic factors also played a significant role. Factors like age, education level, brushing habits, prosthesis age, position, location, and number of units all influenced the likelihood of FPD failure.
This study investigated the factors contributing to FPD failures in a sample of 208 patients in Yemen. Here's a breakdown of the key findings:
• Biological Failures: This study aligns with previous research highlighting biological factors as the primary cause of FPD failures. Poor oral hygiene, periodontal disease, and secondary caries were consistent contributors.
• Mechanical Failures: While less common, mechanical failures, such as fractures and dislodgement, are in line with previous reports.
• Esthetic Failures: Shade mismatch and contour discrepancies were significant aesthetic concerns, consistent with prior studies.
• Oral Hygiene: The strong association between poor oral hygiene and FPD failures is supported by existing literature, emphasizing the importance of preventive care.
• Age and FPD Location: The findings regarding older age and posterior FPD placement being associated with higher failure rates are consistent with previous research.
Contrasting Findings:
• Distribution of Failures: This study deviates from some previous research by finding a higher rate of biological failures compared to mechanical failures. This may be due to variations in study populations, methodologies, or regional differences.
• Number of Units: The lack of a clear relationship between the number of units in an FPD and failure rate contradicts some previous studies. This could be attributed to factors like material quality, fabrication techniques, or patient-specific factors.
Overall, this study provides valuable insights into FPD failures in Yemen and contributes to the growing body of knowledge in this area. While some findings align with previous research, the discrepancies highlight the need for further investigation to understand the complex interplay of factors influencing FPD longevity. Future studies could explore the impact of material selection, fabrication techniques, and patient-specific factors in greater detail.
Limitations
• Radiographic Limitations: The use of two-dimensional radiography may have limited the sensitivity of the study, as compared to three-dimensional imaging, for assessing various parameters. This was due to financial constraints and the desire to minimize patient radiation exposure.
• Age of Prosthesis: The inability to determine the exact age of many prostheses due to patients' lack of recall was a limitation.
Conclusions
Within the limitations of this study, the following conclusions can be drawn:
• Failure Factors: The factors contributing to FPD failures were categorized into three primary groups: biological, mechanical, and aesthetic.
o Biological: Poor oral hygiene, periodontal problems, food impaction, secondary caries, pain, periapical lesions, mobility, abscess formation, and swelling.
o Mechanical: Prosthesis fracture, dislodged prosthesis, fracture of an abutment, and loss of restoration along with abutment teeth.
o Aesthetic: Shade mismatch and contour discrepancies.
• Relationships: There were relationships between failure factors and brushing frequency, number of units, location, and age of the prosthesis.
• No Relationship: No significant relationships were found between failure factors and academic level, gender, or position of the prosthesis (maxillary or mandibular).
• Combined Failures: Some cases exhibited multiple failure reasons, with biological, mechanical, and aesthetic factors contributing in varying combinations.
Recommendations
• Recall System: Establishing a proper recall system for patients who have undergone fixed prosthodontic work is recommended to facilitate early detection and management of complications.
• Material Evaluation: Further studies are needed to investigate the factors influencing the choice of materials for crown and bridgework within the institution. The materials used can significantly impact the success rate and associated complications of these prostheses.
Clearly Auctoresonline and particularly Psychology and Mental Health Care Journal is dedicated to improving health care services for individuals and populations. The editorial boards' ability to efficiently recognize and share the global importance of health literacy with a variety of stakeholders. Auctoresonline publishing platform can be used to facilitate of optimal client-based services and should be added to health care professionals' repertoire of evidence-based health care resources.
