## 4 Discussion  
Based on the results of this in vitro study, thermal aging and manufacturing techniques influence the fracture resistance of temporary crowns and fixed partial dentures, leading to the rejection of the null hypothesis. Provisional restorations must withstand daily oral conditions and occlusal forces for a specific period, especially during full-mouth rehabilitation or dental implant treatments. Additionally, sufficient mechanical strength and stability are crucial to ensuring their functionality, as they are subjected to continuous stress in the oral environment [4]. Accordingly, in this study, both crowns and fixed partial dentures were produced to provide a more comprehensive understanding of their differences. In contrast, previous studies have evaluated the fracture resistance of temporary restorations by fabricating only crowns [2, 8, 19, 20, 21, 22, 23, 24, 25, 26] or fixed partial dentures [3, 6, 7, 10, 27, 28, 29]. To address this gap, temporary crowns and fixed partial dentures were fabricated under identical conditions and subjected to the same procedures. The maximum fracture load at the fracture point was then evaluated. The findings indicated that restorations produced using the SM technique exhibited significantly higher fracture resistance than those fabricated using the CM and AM techniques, with the CM technique also demonstrating statistically higher fracture strength than the AM technique. This result is consistent with the findings of a previous systematic review, which reported that the flexural strength, hardness, and fracture resistance of AM-printed provisional prostheses were lower than those fabricated using conventional and subtractive methods and that their rigidity is insufficient to withstand masticatory forces over extended periods [30]. In line with this, a more recent systematic review concluded that 3D-printed resins exhibit lower flexural strength, fatigue resistance, and microhardness compared to other resin types used for both temporary and permanent restorations [31]. Numerous studies have reported that CM resin generally possesses inferior mechanical properties compared to SM materials [2, 6, 20, 26, 29, 32, 33, 34, 35]. Furthermore, most researchers have noted that AM provisional crown and fixed partial denture resin materials also demonstrate lower mechanical properties compared to SM materials [3, 17, 21, 22, 24, 28, 35, 36]. [PERSON] et al. [17] compared the flexural strength of provisional restoration materials and revealed that those produced using the SM technique demonstrated greater resistance. However, no significant differences were found between materials fabricated using the AM and CM techniques. Similarly, [PERSON] et al. [13] evaluated the flexural strength of provisional restorations fabricated using SLA, DLP, SM, and CM techniques. Their findings indicated that restorations manufactured using the CM technique exhibited lower flexural strength, whereas no significant difference was observed among the other techniques. [PERSON] et al. [2] investigated the fracture strength of provisional crown restorations and reported no significant difference between SM and AM techniques. In contrast, [PERSON] et al. [36] and [PERSON] et al. [3] demonstrated that provisional fixed partial dentures manufactured using the AM technique exhibited lower fracture resistance than those man ufactured using the SM technique. Therefore, evaluating the available materials based on their durability, surface properties, and mechanical performance is essential to determine if they can serve as reliable alternatives to conventionally or subtractively manufactured materials [9]. However, findings vary among those studies directly comparing AM and CM techniques.