Objective:To investigate the establishment, structural, and bonding interface characteristics of an artificial caries-affected dentin model with demineralization and discoloration as a basis of research on caries-affected dentin bonding repair.Methods:One hundred intact molars without caries were collected (acquired from Department of Oral and Maxillofacial Surgery, School & Hospital of Stomatology, Wuhan University from March to May 2023) and prepared as 5 mm thick dentin specimens. Then, they were screened and divided into 3 parts. One part of dentin specimens was subjected to bacterial biofilms to prepare artificial carious dentin (ACD). They were further ground by 600-grit SiC paper for 0, 12, 24, 36, and 48 s, respectively to obtain 5 groups with different layers of ACD: ACD-0, 12, 24, 36, and 48 s. Sound dentin was used as the control group. To determine the preparation parameter for artificial caries-affected dentin (ACAD), the first part of specimens was used for bacterial visualization observation ( n=3) and demineralization analysis experiments (micro-CT, Raman spectroscopy, and surface micro-hardness analyses, n=3). Another part of dentin specimens was allocated to 3 groups: control group (sound dentin), artificial caries-infected dentin group (ACD-0 s) and ACAD group (prepared according to the parameter determined by the experiments above). They were used for color tests ( n=10), Raman spectroscopy analysis ( n=6) and scanning electron microscope (SEM) observation ( n=1), thus comparing color, chemical composition and structure, and micro-morphology of 3 groups. The rest of dentin specimens were divided into 2 groups: sound dentin and ACAD ( n=6), which were bonded to composite resin with Single Bond Universal in a self-etch mode. Then, the bonding interface was measured using an electron probe micro-analyzer (EPMA). Results:The depth of bacterial invasion for ACD-0 s was (142.4±25.8) μm. And obvious bacteria were observed in the dentin tubules for the ACD-12 s group. For micro-CT, the demineralization depth was (283.9±25.6) μm for ACD-0 s and (139.2±27.9) μm for ACD-36 s. The grey values in some regions of the dentin surface for ACD-48 s resembled those of sound dentin. For Raman spectroscopy, the peak ratio of phosphate to amide Ⅰ was significantly lower for ACD-24 s [4.2 (3.2,6.7)] than ACD-36 s [6.7 (6.0,7.7)] ( P<0.05). Additionally, there was no significant difference in surface micro-hardness between ACD-24 s [8.3 (7.0,10.2) HV] and ACD-36 s [10.2 (9.1,11.4) HV] ( P>0.05). The preparation parameter of ACAD was determined to be grinding for 36 s based on the experimental results above. The brightness (L * value) and the yellow-blue chromaticity (b * value) of ACAD (76.69±2.54, 33.15±1.89) were significantly lower than those of the control group (85.23±1.68, 35.87±1.55) ( P<0.05). The red-green chromaticity (a * value) of ACAD (5.38±1.20) was significantly higher than that of the control group (0.71±0.86) ( P<0.05). Moreover, the collagen structure parameter in Raman spectroscopy (the peak ratio of amide Ⅲ to CH 2) of ACAD (1.089 7±0.038 5) was significantly higher than that of the control group (0.985 2±0.020 1) ( P<0.05). As shown in EPMA, the hybrid layer of ACAD [(4.72±1.03) μm] was significantly thicker than that of sound dentin [(3.02±0.66) μm] ( F=21.09, P<0.001) in a self-etch mode. Conclusions:ACAD is established through bacterial biofilm challenges followed by grinding for 36 s. It is partly demineralized and discolored with collagen structure changes, making it suitable for research on caries-affected dentin bonding.

Objective:To investigate the establishment, structural, and bonding interface characteristics of an artificial caries-affected dentin model with demineralization and discoloration as a basis of research on caries-affected dentin bonding repair.Methods:One hundred intact molars without caries were collected (acquired from Department of Oral and Maxillofacial Surgery, School & Hospital of Stomatology, Wuhan University from March to May 2023) and prepared as 5 mm thick dentin specimens. Then, they were screened and divided into 3 parts. One part of dentin specimens was subjected to bacterial biofilms to prepare artificial carious dentin (ACD). They were further ground by 600-grit SiC paper for 0, 12, 24, 36, and 48 s, respectively to obtain 5 groups with different layers of ACD: ACD-0, 12, 24, 36, and 48 s. Sound dentin was used as the control group. To determine the preparation parameter for artificial caries-affected dentin (ACAD), the first part of specimens was used for bacterial visualization observation ( n=3) and demineralization analysis experiments (micro-CT, Raman spectroscopy, and surface micro-hardness analyses, n=3). Another part of dentin specimens was allocated to 3 groups: control group (sound dentin), artificial caries-infected dentin group (ACD-0 s) and ACAD group (prepared according to the parameter determined by the experiments above). They were used for color tests ( n=10), Raman spectroscopy analysis ( n=6) and scanning electron microscope (SEM) observation ( n=1), thus comparing color, chemical composition and structure, and micro-morphology of 3 groups. The rest of dentin specimens were divided into 2 groups: sound dentin and ACAD ( n=6), which were bonded to composite resin with Single Bond Universal in a self-etch mode. Then, the bonding interface was measured using an electron probe micro-analyzer (EPMA). Results:The depth of bacterial invasion for ACD-0 s was (142.4±25.8) μm. And obvious bacteria were observed in the dentin tubules for the ACD-12 s group. For micro-CT, the demineralization depth was (283.9±25.6) μm for ACD-0 s and (139.2±27.9) μm for ACD-36 s. The grey values in some regions of the dentin surface for ACD-48 s resembled those of sound dentin. For Raman spectroscopy, the peak ratio of phosphate to amide Ⅰ was significantly lower for ACD-24 s [4.2 (3.2,6.7)] than ACD-36 s [6.7 (6.0,7.7)] ( P<0.05). Additionally, there was no significant difference in surface micro-hardness between ACD-24 s [8.3 (7.0,10.2) HV] and ACD-36 s [10.2 (9.1,11.4) HV] ( P>0.05). The preparation parameter of ACAD was determined to be grinding for 36 s based on the experimental results above. The brightness (L * value) and the yellow-blue chromaticity (b * value) of ACAD (76.69±2.54, 33.15±1.89) were significantly lower than those of the control group (85.23±1.68, 35.87±1.55) ( P<0.05). The red-green chromaticity (a * value) of ACAD (5.38±1.20) was significantly higher than that of the control group (0.71±0.86) ( P<0.05). Moreover, the collagen structure parameter in Raman spectroscopy (the peak ratio of amide Ⅲ to CH 2) of ACAD (1.089 7±0.038 5) was significantly higher than that of the control group (0.985 2±0.020 1) ( P<0.05). As shown in EPMA, the hybrid layer of ACAD [(4.72±1.03) μm] was significantly thicker than that of sound dentin [(3.02±0.66) μm] ( F=21.09, P<0.001) in a self-etch mode. Conclusions:ACAD is established through bacterial biofilm challenges followed by grinding for 36 s. It is partly demineralized and discolored with collagen structure changes, making it suitable for research on caries-affected dentin bonding.

Objective:To compare the differences of clinical characteristics of temporal lobe epilepsy with bilateral hippocampal sclerosis (TLE-bHS) with those of temporal lobe epilepsy with unilateral hippocampal sclerosis (TLE-uHS).Methods:A retrospective analysis was performed. Forty-eight patients with confirmed TLE-bHS enrolled in Epilepsy Center, Department of Neurology, Second Affiliated Hospital, Medical School of Zhejiang University from January 2013 to January 2022 were chosen, and 101 patients with confirmed TLE-uHS admitted to our hospital at the same time period were selected as controls. Clinical data such as onset age, disease course, past medical history, seizure frequency, anti-seizure medications, video EEG and neuropsychological test results, and outcomes were analyzed.Results:Compared with the TLE-uHS group, the TLE-bHS group had higher male proportion, elder onset age, shorter disease course, higher seizure frequency, more types of past and currently used anti-seizure medications, lower proportion of autonomic nerve with aura, higher proportion of no aura at onset, higher proportion of slow head background movement in video EEG, and lower memory quotient, verbal memory scores and non-verbal memory scores, with significant differences ( P<0.05); the differences in ratio of past medical history and ratio of distributions of regions with interictal epileptiform abnormalities between the 2 groups were statistically significant ( P<0.05): the TLE-bHS group had significantly higher proportion of previous intracranial infection/encephalitis and higher ratio of bilateral temporal epileptiform abnormalities than the TLE-uHS group, while the TLE-uHS group had significantly higher proportion of patients with febrile convulsion history and higher ratio of unilateral temporal epileptiform abnormalities ( P<0.05). Only 10 patients (20.8%) in the TLE-bHS group received non-drug therapy, including anterior temporal lobectomy in 3 patients (Engel grading I in postoperative follow-up for 2 years), neuroregulatory therapy in 4, and ketogenic diet in 4; of the 55 patients (54.5%) in the TLE-uHS group who underwent anterior temporal lobectomy, 48 patients (87.3%) had Engel grading I, 1 patient (1.8%) had grading II, 4 (7.3%) had grading III, and 2 (3.6%) had grading IV after 2 years of follow-up. Conclusion:Differences in onset age, disease course, past medical history, seizure frequency, anti-seizure medications, and video EEG and neuropsychological test results can help to discriminate patients with TLE-bHS or with TLE-uHS.