After the preparation of vital abutments, by opening the dentinal tubules the apparition of different degrees of dentin sensibility (DS) can be induced.
Preparation of the teeth for full crowns can induce drying of the dentin, pulpal inflammation or even burn lesions after the reduction of the odontoblastic layer. Clinical researches demonstrated that the preparation of vital teeth for full coverage fixed prosthetic restorations can determine sharp, transient pain as a result of DS [1].
The hydrodynamic theory of dentin hypersensitivity (DHS) suggests that external stimuli determine movements in the fluid of dentin tubules, which induce nociceptive transduction in adjacent pulpal nerve fibers [2-4]. Dentinal tubules contain the odontoblastic processes, which may extend from the pulp to the dentino-enamel junction. The odontoblastic processes are the extensions of odontoblasts and they are surrounded by dentinal fluid inside the dentin tubules. The dentinal fluid is an ultrafiltrate of blood from the dental pulp and represents the communication between the dental pulp through the odontoblastic layer and the outer regions of the dentin [5,6]. DS is characterized by a short and sharp pain, with a rapid onset. DS occurs after the removal of the protective smear layer, which determines the opening of dentinal tubules and the exposure of the odontoblastic processes to chemical, thermal, tactile or osmotic stimuli [6,7,8]. Great variations were observed in the prevalence of DS, which varies from 4% to 57% [9,11]. Sealing the dentinal tubules represents a current method in decreasing DS [11]. The therapeutic approach of closing the dentinal tubules, in order to impede the fluid shifts from the dentinal tubules, is represented by the application of chemical and mechanical methods in dentin desensitization. Significant advancement in the understanding and in treatment of DH, have been developed, respectively in the use of various methods and desensitizing agents [8,12].