SPECTROCOLORIMETRIC STUDY OF GINGIVAL MICROVASCULAR REACTIVITY DURING PROSTHODONTIC TREATMENT USING FIXED DENTAL PROSTHESES

Abstract

Objective optical monitoring may reveal gingival microvascular dysfunction and inflammatory chromatic changes that are not fully captured by visual examination. The purpose of the study was to evaluate longitudinal changes in gingival microvascular reactivity to a standardized masticatory load and the iodine-associated spectrocolorimetric response during implant-supported and tooth-supported fixed prosthetic rehabilitation, and to determine whether adjunctive multicomponent support was associated with more favorable six-month optical outcomes than basic care alone. Materials and methods. This longitudinal, nonrandomized comparative study included 76 adults aged 18–30 years with a bounded single-tooth edentulous space. Diagnostic stratification determined rehabilitation with two-stage implants (group 1.1, adjunctive regimen, n=20; group 1.2, basic care, n=17) or three-unit metal–ceramic fixed dental prostheses supported by two teeth (group 2.1, adjunctive regimen, n=22; group 2.2, basic care, n=17). An automated spectrocolorimeter recorded gingival reflectance-derived CIE X, Y, and Z tristimulus coordinates before and after a protocol-defined masticatory load and before and after Schiller–Pisarev iodine staining. Measurements were obtained at baseline, after preliminary therapy in the intervention groups, and 1 and 6 months after surgery or prosthesis fixation Statistical analysis was performed in STATISTICA 6.1 using Student’s t-test (p < 0.01). Research results. At baseline, the implant- stratified groups showed a positive optical microvascular response to loading, whereas the bridge-stratified groups showed a negative response. At 1 month, load reactivity was attenuated or negative in all groups. By 6 months, group 1.1 demonstrated increases of +3.5, +2.5, and +2.7 units in X, Y, and Z after loading, while group 1.2 showed negligible changes (−0.1, +0.1, and +0.1). Group 2.1 shifted toward a positive response (+0.3, +0.3, and +0.4), whereas group 2.2 retained a negative response (−2.0 for each coordinate). At 6 months, the relative iodine-associated coordinate changes were 5.3–6.5% in group 1.1 versus 14.2–15.5% in group 1.2, and 16.2–17.9% in group 2.1 versus 25.9–27.8% in group 2.2 (p<0.001 for each adjunctive-versus-comparison contrast). Conclusions. Within each rehabilitation stratum, adjunctive multicomponent support was associated with more favorable recovery of the gingival optical response to functional loading and a smaller iodine-associated chromatic shift at 6 months. These findings support standardized optical monitoring as a complementary method for longitudinal assessment of peri-prosthetic soft tissues, while the nonrandomized design precludes direct causal comparison of implants and bridges.