Radiographs supplement the clinical examination by providing important information. A thorough understanding of the extent of bone support and root morphology of each standing tooth is required to develop a comprehensive crown and bridge treatment plan . The majority of surveyed dentists use radiographs for the abutment tooth or teeth in crown and bridge work, both frequently (40.94%) and infrequently (35.57%).
Treatment outcome evaluation remains critical in providing scientific evidence that informs treatment planning and patient education for decision making. Over a seven-year period, crowns and FPDs provided at the School of Dental Sciences were evaluated.
In comparison to primary health care centers, crowns and FPDs were mostly performed at Hail dental polyclinics center practice. In other countries, such as the United Kingdom, more crown and FPDs work in the National Health Service (NHS) rather than in private practice .
In our study, the success rate for crowns was low. This was significantly lower than the success rate for crowns reported in various studies [12–15]. Cheung et al.  discovered a 20.7% failure rate for a mean length of service of 35 months. Hochman et al.  reported a failure rate of 6% for a mean lifespan of 6.3 years, whereas Libby et al.  reported a failure rate of 15% for a mean service length of 16 years. Vaulderhaug et al.  conducted a 15-year prospective study and found failure rates of 4%, 12%, and 32% after 5, 10, and 15 years, respectively.
Researchers identified several critical areas of concern with provisional restorations, including esthetics, comfort, speech and function, periodontal health, maxillomandibular relationships, and continued evaluation of the fixed prosthodontic treatment plan [16–18]. Provisional treatment can also be an important tool in the psychological management of patients when there is a mutual understanding of treatment outcome and limitations . The use of provisional restorations is dependent on a reasonable turnaround time between tooth preparation and the completion of definitive treatment. When this happens, provisional treatment is usually well tolerated. Longer time-periods of use can promote tooth sensitivity and potential pulp damage . The most common complications associated with crowns in the current study were defective margins, porcelain fractures, and non-acceptable color matching. These findings were consistent with those of Goodacre et al , who reported that porcelain fractures and defective margins were among the most common complications associated with crowns. However, the findings differed slightly in that, whereas Goodacre et al.  highlighted the need for endodontic treatment as one of the most common complications, there was no incidence of a crowned tooth requiring endodontic treatment in this study. This may be due in part to the study's relatively short average length of service. Crowns and FPDs were both plagued by porcelain fractures and faulty margins. Intra-oral porcelain is prone to fracture. High occlusal forces, trauma, incompatible coefficients of thermal expansion between the porcelain and the metal alloy, low-elastic modulus of the metal alloy, improper design, and micro-defects within the porcelain material can all cause fracture . Due to the exposure of underlying metal, this complication usually presents an esthetic challenge, especially in the esthetic zone.
The majority of crowns and FPDs in our study that had defective margins that could not be corrected were recommended for replacement. Marginal gaps, positive or negative margins, and defective margins can all be signs of defective margins. Positive margins can be corrected in the absence of a gap. However, marginal gaps and negative ledges pose a much larger problem that is difficult to correct and frequently necessitates prosthesis replacement .
Defective margins can occur as a result of clinical or laboratory errors. Clinical errors can occur as a result of improperly prepared finish lines or insufficient gingiva retraction during impression taking. The presence of air bubbles within the impression's margin may also contribute to these errors. Localized periodontal inflammation can be exacerbated by poor marginal adaptation, subgingival margin placement, and over-contoured crowns. Vaulderhaug et al.  conducted a longitudinal study to assess periodontal conditions in FPD patients. They discovered that the gingiva of crowned teeth was more commonly affected.
Long-term success requires accurate marginal fit of indirect restorations. This is due to the fact that ill-fitting margins make the tooth more susceptible to cement dissolution; once this occurs, marginal leakage occurs, which usually results in secondary caries and, if unnoticed, can lead to abutment vitality loss. Ill-fitting margins also cause plaque retention, predisposing the abutment to recurrent caries. Defective subgingival margins may jeopardize gingival health by altering local bacteria.
After a long period, biological complications such as caries and loss of vitality have been observed . Some studies [26–28] found no secondary caries. Secondary caries was found in 21.7% of the FPDs cemented with resin cement in a 5-year clinical study of posterior Cercon FPDs by Sailer et al. . Secondary caries was discovered in 8.7% of the FPDs in the current study. This could be because the average length of service in our study was 1–10 years. The FPDs' comparatively shorter mean length of service may explain the low incidence of caries and loss of vitality in this study (3.5 years). It could also be attributed to careful patient selection for crowns and FPDs, as the population studied had generally good oral hygiene, with a low average plaque score of 1.4. This could be an indication that patients chosen for these types of treatments were well-motivated patients who practiced good oral hygiene and thus had a low caries risk. On the other hand, the presence of defective margins in many of the failed restorations may imply that these crowned and abutment teeth will be susceptible to caries and loss of vitality in the long run.
Porcelain-fused-to-metal (PFM) has long been regarded as the gold standard for prosthetic fabrication due to its ability to combine good mechanical properties with acceptable esthetic results, as well as its ability to provide biological quality required for periodontal health . This could explain why it was chosen for 44 (14.7%) crowns and 242 (80.7%) FPDs in this study.
Patients' perceptions of success have been shown to differ from those of clinicians. It was interesting to note that patient attitudes toward the prostheses did not always match the clinician's findings. Out of 300 prostheses, 81 (27%) were rated as satisfactory by patients. As a result, patient satisfaction may not be a reliable predictor of success.
There are several repair systems available for repairing fractured porcelain; these systems typically involve the bonding of resin composite to the fractured porcelain. This technique has a poor long-term prognosis due to the composite's decreasing bond strength to porcelain over time, increased wear on the composite when compared to porcelain, and poor color stability associated with resin composites . Furthermore, color matching porcelain to composite is difficult due to differences in optical properties, so this technique frequently results in inferior esthetics.
The current study represented clinical evaluation and periapical status of fixed prosthodontic restorations in a selected Saudi population, and it provided a theoretical basis for clinical care to some extent. The sample size and experimental method had a significant impact on the outcomes of fixed prosthodontic restorations. However, there are a few drawbacks that must be addressed. Because this was a single-center study, the sample size should have been larger. Furthermore, the resolution of the traditional radiographs used in this study was lower than that of the CBCT, which may have influenced the results. Further multicenter research using advanced techniques such as CBCT may be able to overcome the limitations of the current study.