## 1 Introduction  
Vital pulp therapy (VPT) is a treatment approach that is intended to protect and heal pulp tissue damaged by extensive caries, dental trauma, restorative procedures, or iatrogenic factors. VPTs are based on the principle of minimally invasive therapy and include procedures such as partial pulotomy, full pulpotomy, and pulp capping [1, 2]. VPTs using appropriate techniques and materials may reduce the progression of dental pulp disease. Given that the pulp-coating material comes into direct contact with the strongly vascularized pulp tissue, it is essential that such materials are biocompatible and non-toxic. Furthermore, because the clinical success of VPT depends on both appearance and tissue preservation, color stability and high biocompatibility should be considered integral clinical requirements [1; 3]. The evolution of calcium silicate cements (CSCs) has been characterized by substantial modifications, including the incorporation of alternative radiopaque substances and additives. The integration of bio-ceramics within dental procedures has been demonstrated to be particularly effective in the repair of root perforation and VPT. This is due to the former's advantageous handling characteristics and rapid setting time, which renders them wash resistant upon contact with moisture [4; 5]. Recently, a range of premixed putty-type bioactive ceramic cements (PPBCs) have been formulated and commercialized in capsule, syringe, and needle syringe formats [5]. EndoCem MTA Premixed (ECPR) (Maruchi, Wonju, Republic of Korea), NeoPUTTY (NuSmile, Houston, TX, USA), and Bio-C Repair (Angelus, Londrina, Brazil) are examples of new PPBCs [5; 6; 7]. In a previous study, it was found that although ECPR has a longer setting time than Endocem(r) MTA Zr and RetroMTA; however, it is a promising material in that it has improved solubility and compressive strength and can be shortened because of the properties of premixed CSC [8]. NeoPutty is non-staining because it contains a non-staining radiopaque agent known as tantalum oxide, which does not cause tooth discoloration [9]. Bio-C Repair (Angelus, Londrina, Brazil) is another premixed bio-ceramic cement. It has the same properties as white MTA, in addition to cytotoxicity, bioactivity, and biomineralization. It contains zirconium oxide, which acts as a radiopaque agent [7; 10; 11]. Laser technologies and dentin-bonding agents (DBAs) are increasingly being considered for use in surface pretreatment prior to CSC application. Nd-YAG laser treatment has been shown to occlude dental tubules via melting and recrystallization, which reduces dentin permeability and may help prevent the diffusion of discoloring agents [10; 11]. Similarly, DBAs have been reported to reduce crown discoloration when applied to dentin surfaces, likely via blocking tubular pathways and preventing blood infiltration [12]. However, the biological implications of such pretreatment methods remain a subject of concern. When DBAs are applied directly onto exposed pulp tissue, they may cause persistent inflammation, impair healing, and hinder dentin bridge formation [13]. The resulting polymer layer could obstruct cellular migration and mineral deposition, ultimately interfering with the regenerative potential of calcium silicate-based materials. In contrast, when DBAs are limited to dentin surfaces without direct pulp contact, they may offer aesthetic benefits by sealing dental tubules [14; 15; 16]. There are aesthetic challenges involved in treating young permanent incisors, especially those with traumatic pulpal injury. Any coronal discoloration will be disturbing during the patient's developmental years. In such cases, PPBCs have been proposed as pulp-protective materials; yet, only a few studies have examined their coronal color stability, and long-term clinical evidence remains inconclusive. Furthermore, no investigation has yet explored whether dentin surface pretreatments--such as Nd-YAG laser irradiation or the application of a DBA--modify the coronal discoloration behavior of PPBCs [12; 17].