Background/purpose: How long do lithium disilicate restorations last before they fail? The aim of this study was to assess the success rate of four different types of restorations made from lithium disilicate. Materials and methods: A total of 87,203 ceramic restorations, classified into four different types (inlay or onlay, veneers (Vs), single crowns (SCs), and fixed partial dentures (FPDs)), were used. All were made of lithium disilicate (IPS e.Max CAD) with Cerec Inlab CAD/CAM system (Sirona Dental Systems, Bensheim, Germany). They were reported by dentists and entered in the database of the private B&R Dental Center between March 2015 and June 2020 and assessed retrospectively up to a period of 5 years based on the following parameters: failure rate and cause of failures (ceramic fracture, debonding, marginal adaptation, color match, endodontic intervention, periodontal disease, and secondary caries). Failure distribution according to gender, arch, and teeth type was also evaluated. The time-dependent time-to-failure/complication and their differences were calculated in months according to the Kaplan Meier and log-rank tests. The Chi-squared test (p 0.05) was used to assess the variations in causes of failure rates between different restorations. Results: Kaplan Meier test showed overall cumulative survival probability of lithium disilicate restorations for up to years was 85.08%. Inlay/onlay and Vs ceramic restorations showed highest cumulative survival probability (99.4%, 98.6, respectively). FPDs had the least cumulative survival probability (52.9%) which was significantly (P < 0.00001) higher than for other ceramic restorations using the log-rank test. Moreover, overall time-dependent time-to-failure/complication occurred after 52.373 months according to Kaplan–Meier (CI: lower bound: 51.875 months; upper bound: 52.871 months). Ceramic fracture in both FPDs and SCs (27.6% and 26.6%, respectively) and debonding in Vs (12.7%) were significant as the main reasons for failure (P = 0.000). The failure rate was significantly higher for the maxillary arch than the mandibular arch (P = 0.021). Fracture and marginal discrepancy were more frequent in the molar region (77.5% and 14.75%, respectively) and significantly higher here than in the anterior and premolar regions (P = 0.000). Conclusion: The medium-term performance of lithium disilicate is ideal. Ceramic fracture was the most common cause of failure in SCs and FPDs. FPDs presented with the highest failure rate based on evaluation for up to 5 years.

Background/Objectives: The purpose of this study was to measure the bone thickness and angulation of the maxillary and mandibular anterior teeth on the buccal and palatal/lingual sides and also to analyze the sagittal root position (SRP) in the alveolar bone in relation to age and gender using cone-beam computed tomography (CBCT) in an Iraqi subpopulation. Methods: CBCT images of 1200 maxillary and mandibular central and lateral incisors and canines from 100 patients (48 males and 52 females) were retrospectively analyzed. These patients were categorized by age into group I ≤ 25, group II 26–40, and group III ≥ 41 years old. The SRP in the alveolar bone was classified as class I, class II, class III, and class IV, and the buccal type was further classified into subtypes I, II, and III. In addition, the buccolingual inclination of the tooth and buccal/palatal/lingual bone thickness at the coronal, middle, and apical thirds were evaluated and then compared based on age and gender. The data were analyzed using the Pearson chi-square test. Descriptive statistics, Kruskal–Wallis and Mann–Whitney U test were used to compare the thickness and angulation according to the SRP classes. Results: The mean frequency distribution of SRP of maxillary anterior teeth indicated that most of them were located buccally and were classified as (Class I) and subtype (III). Moreover, for mandibular anterior teeth, the majority were classified as (Class IV) and subtype (II). The mean sagittal angulation of maxillary anterior teeth approximately ranged from 5.9 for tooth 12# to 8.2 for teeth 13# and 23#, while for mandibular anterior teeth it ranged from 7.4 for tooth 33# to 10.3 for tooth 41#. The thickness of bone in the apical third of the buccal side of all maxillary and mandibular teeth was significantly related to age (p < 0.05). In the middle third, the thickness of bone in the buccal and palatal side of all maxillary anterior teeth and in the apical third of most mandibular teeth in the lingual side was significantly higher in males (p < 0.05). Conclusions: A majority of the maxillary anterior tooth roots were positioned close to the buccal cortical plate, while most of the mandibular anterior teeth were engaging both the buccal and lingual cortical plates. Males had more alveolar bone thickness for both maxillary and mandibular anterior teeth, and only the apical portion significantly changed with age. CBCT of the buccal and palatal/lingual bone and SRP is recommended for the selection of the appropriate treatment approach and implant placement.

Objective: Posterior bite raisers (PBRs) induce temporary posterior disocclusion during fixed orthodontic treatment but may affect pulp vitality under prolonged occlusal load. Objective: To compare pulpal responses to injectable nanohybrid composite PBRs and resin-modified glass ionomer cement (RMGIC) PBRs at two heights (1–2 mm; >2–4 mm) in relation to gender and age. Methods: Eighty patients (16- 40 years old, with a mean age of 22.9 ± 5.7 years and an equal male-to-female ratio were assigned to four groups according to the material and height of PBRs, with twenty patients in each group. Cold testing and electric pulp testing (EPT) were documented at baseline, 1 week, 1 month, 2 months, and 3 months. The outcomes were divided into two groups: sensibility (positive or negative), and the differences among the four groups were compared in relation to gender and age. Results: At 3 months, negative pulpal responses were observed only in the composite groups: >2–4 mm (15%) and 1–2 mm (5%). Material choice was the strongest independent predictor of EPT threshold change (P=0.008), with the composite associated with significantly decreased responsiveness. The interaction between material and height was highly significant (p=0.012), indicating a fivefold higher risk of negative sensibility responses with high-volume composite than with RMGIC. Younger patients showed greater susceptibility to pulpal changes (p=0.03). Conclusions: Composite PBRs, particularly at heights exceeding 2 mm, are associated with increased pulpal stress, whereas RMGIC demonstrates superior pulpal stability and is recommended for initial orthodontic phases to minimize adverse biological effects.

Objective: Patient perception increasingly influences the selection of restorative dental materials, especially as aesthetic expectations grow within modern dental practice. This study aimed to evaluate patient awareness, attitudes, and preferences regarding amalgam and tooth-coloured restorative materials in Sulaimaniyah City. Methods: A descriptive cross-sectional survey was conducted using a structured questionnaire distributed to patients attending various dental clinics. The questionnaire obtained demographic information, previous restorative experiences, aesthetic expectations, and perceptions of the functional, aesthetic, and biological characteristics of amalgam and composite resin materials. Results: The results showed that most participants preferred tooth-coloured restorations due to their natural appearance and higher aesthetic compatibility. Amalgam was favoured by a smaller proportion of respondents who emphasized its durability, strength, and relative affordability. Younger patients and those with higher educational levels demonstrated stronger preference for aesthetic materials, while awareness of possible health concerns associated with amalgam varied considerably among participants. Conclusions: Overall, the findings reflect a noticeable shift toward aesthetic-driven choices in restorative dentistry within the region. The study concludes that dental practitioners should acknowledge patient preferences during treatment planning and provide balanced, evidence-based information about the advantages and limitations of available restorative materials to support informed decision-making and enhance patient satisfaction.