Quintessence international最新文献

Objective: The aim of this retrospective study was to evaluate the effects of high preoperative C-reactive protein (CRP) levels on early peri-implant alveolar bone loss.

Method and materials: Fifty-eight implants in 20 patients with high preoperative CRP levels and 54 implants in 20 patients with low preoperative CRP levels were evaluated. For measurement of the peri-implant alveolar bone loss, the implant platform was accepted as the reference point. On both the mesial and distal sides, the vertical distances between the reference point and the first visible bone's highest coronal level were measured. Numerical data were compared between groups using the independent sample t test or the Mann-Whitney U test. Correlations between variables were investigated with the Spearman rho test.

Results: The mean CRP level of the low CRP group was 0.37 ± 0.21 mg/L, while that of the high CRP group was 1.71 ± 0.60 mg/L. In the high CRP group, implant failure was observed in two patients. The mesial bone loss and distal bone loss values in the group with high CRP levels were found to be significantly higher than the group with low CRP levels (P < .05). There was a significant positive correlation between the CRP levels, and distal bone loss and mesial bone loss measurements.

Conclusion: The results show that high preoperative CRP levels result in an increased risk for peri-implant alveolar bone loss, and suggest that preoperative CRP levels can be important for early peri-implant alveolar bone loss.

Nowadays, complication-free wound healing processes are the key to successful treatment outcomes in the context of periodontal and implant surgery, both clinically and scientifically. The main challenge here is to achieve primary wound healing in the majority of cases. Among the scientifically documented factors that influence the healing process, it is primarily the blood supply in the surgical area and the stability of the wound achieved postoperatively that can be directly influenced by the clinician. The surgical wound closure plays a decisive role in this context in order to achieve sufficient stabilization of the wound without negatively affecting the healing process through unnecessary traumatization of the tissue or excessive tensile forces on the wound edges. It is important to bear in mind that wound healing after surgical procedures in the oral cavity does not take place under optimal conditions. A moist, microbiologically contaminated environment is present and complete immobilization of the wound is hardly possible during the early healing phases. The sutures must therefore ensure that the surgical flaps are passively secured in the intraoperatively established position, that the wound edges are in as close contact as possible - especially if grafts that initially rely on nutrition through plasmatic circulation are used - and that the wound is stabilized during the first few postoperative days. The suture material and suturing technique must be selected so that the knots do not loosen and both the suture material and soft tissue can withstand the mechanical stresses during the early wound healing phases. The search for available mechanical anchors should be the focus of interest.

Objectives: This study aimed to evaluate the physical-mechanical behavior of resin composites when subjected to different prolonged heating protocols.

Method and materials: A total of 150 specimens were divided into 15 groups (n = 10 per group) based on the restorative materials (Filtek Supreme, VisCalor, and Grandioso) and heating protocols: room temperature (22°C), 24 hours at 68°C, 7 days at 68°C, 30- and 100- cycles of artificial aging by thermocycling (5 and 68°C for 10 minutes each). The materials were inserted into a PVS matrix, cured for 20 seconds using a 1,000 mW/cm2 LED light-curing unit, and stored for 24 hours. The response variables measured were flexural strength and Knoop microhardness.

Results: The flexural strength evaluation showed that Grandioso exhibited higher strength compared to Filtek Supreme and VisCalor, with no significant differences observed across the heating protocols. This indicates that prolonged heating did not affect the flexural strength of any of the tested resins. Knoop microhardness testing revealed significant differences among resins and heating protocols. Grandioso demonstrated the highest surface hardness across all protocols, whereas Filtek Supreme showed a decrease in hardness after 100 thermocycling cycles. Prolonged heating reduced surface hardness for Grandioso and VisCalor compared to room temperature, whereas Filtek Supreme maintained its hardness under extended heat exposure.

Conclusion: These findings suggest that while flexural strength remains unaffected by heating, surface hardness varies depending on the resin type and the heating duration.

Objectives: To analyze the effects of three osteotomy drill designs (conventional, reverse helix, and densification) and running directions on heat generation, primary implant stability, block-to-implant contact, peri-implant block volume, and resistance to unscrewing forces in a low-density alveolar bone model.

Method and materials: Eighty-eight dental implants were placed in artificial bone blocks using manual and computer-controlled osteotomies. Temperature changes, insertion torque value, resonance frequency analyses (implant stability quotient [ISQ]), block-to-implant contact, and peri-implant block volume were measured. Statistical analyses used ANOVA and Kruskal-Wallis tests (P < .05).

Results: Densification drill designs produced the lowest temperature change (17.52 ± 2.57°C and 28.06 ± 4.35°C for the second and third drills), while conventional drills had the highest (27.53 ± 5.17°C and 38.03 ± 8.08°C). Counter-clockwise (CCW) conventional drilling significantly reduced the temperature change compared to clockwise (CW). Densification drill designs achieved the highest primary implant stability (38.01 ± 1.87 N/cm, 65.00 ± 4.69 ISQ) and removal torque (25.40 ± 5.08 N/cm), while conventional CW drills had the lowest (33.23 ± 2.91 N/cm, 61.83 ± 4.28 ISQ). Densification drill designs showed the highest peri-implant block volume (87.71 ± 4.23 mm3) but the lowest block-to-implant contact (49.12 ± 2.93%). CCW conventional drilling improved insertion torque value over CW (36.21 ± 3.63 vs 33.23 ± 2.91 N/cm).

Conclusion: Densification drill designs demonstrated better performance in heat reduction, primary implant stability, and peri-implant block volume, but had lower block-to-implant contact. CCW running of conventional drills showed improvements over CW in several parameters. While densification drilling excelled in most aspects, its lower block-to-implant contact and the positive outcomes of CCW conventional drilling warrant further investigation.

Objectives: This in-vitro study aimed to investigate the influence of different pretreatments and surface coatings on the wear of different zirconia and their antagonists.

Method and materials: Zirconia specimens (3-, 4- and 5-mol% yttria tetragonal zirconia; n = 160/material) were subjected to pretreatment (airborne-particle abrasion, 50 µm Al2O3, 1 bar; 120 µm Al2O3, 3 bar; polishing) and surface coating (spray glazing, micro-layering, layering, veneering). References comprised no pretreatment or coating. Wear tests were performed (50 N, 120,000 cycles). Wear (mean, maximum, antagonist) and arithmetic mean roughness Ra and average roughness depth Rz were determined. ANOVA, Bonferroni, and Pearson correlation (α = .05) were performed.

Results: Ra/Rz showed significant (P < .001) differences (Ra: 0.01 ± 0.01 µm to 0.71 ± 0.06 µm; Rz: 0.31 ± 0.09 µm to 4.33 ± 0.44 µm). Two groups could be distinguished by mean and maximum wear with significant (P < .001) differences: (1) glaze sprayed and without coating (mean wear: 9.4 ± 2.6 µm to 57 ± 21.3 µm, max. wear: 24.1 ± 6.9 µm to 125.4 ± 18.2 µm) and (2) all coating procedures (mean wear: 129.2 ± 22.8 µm to 236.5 ± 62.0 µm; max. wear: 188.7 ± 21.4 µm to 444.2 ± 110.6 µm). Antagonist wear (9.2 ± 4.5 to 29.7 ± 5.0%) showed a significant (P < .001) correlation to surface coating, mean and maximum wear, and Ra and Rz. Mean wear significantly (P < .001) correlated with surface coating, maximum wear, and antagonist wear.

Conclusion: Under clinical conditions, layering or veneering can lead to increased wear of the restoration, but in return reduce the abrasion of antagonists. Excessively rough surface treatments should be avoided, as they might increase antagonist wear.

Molar-incisor hypomineralization (MIH) is a qualitative developmental defect of the enamel that affects one or more permanent first molars, with or without incisor involvement. This condition often requires esthetic treatment, and therapeutic approaches may vary considerably. This case report describes a step-by-step clinical protocol for a 20-year-old woman who presented with dissatisfaction regarding the appearance of her smile due to hypomineralized spots on the maxillary and mandibular anterior teeth. After anamnesis and clinical examination, the diagnosis of MIH was established. Treatment consisted of in-office bleaching followed by resin infiltration for the maxillary teeth, and microabrasion combined with resin infiltration for the mandibular teeth. This sequence of minimally invasive techniques effectively resolved the esthetic alterations caused by MIH, showing satisfactory results that remained stable over 1 year.

Purpose: To evaluate parents' knowledge of the Israeli Ministry of Health guidelines on basic oral health practices and appropriate toothpaste usage for different pediatric age groups.

Method: Anonymous questionnaires were distributed to parents attending the Pedodontics Department. The questionnaire included two sections: general questions and questions that were completed for all children in the family, categorizing them into three age groups-under 2 years, 2-6 years, and over 6 years.

Results: A total of 242 questionnaires and 410 responses across different age groups were collected. Most respondents knew that teeth should be brushed as soon as the first tooth appears and believed that the first dental visit should be at age two (60.5% and 26.9%, respectively). However, only 15% of parents answered boths questions correctly. Toothpaste selection was primarily based on age (46.6%), with no significant differences across age groups for correct answer (p = 0.130). Awareness of the recommended fluoride concentration was low (16.1%), though parents of older children showed better knowledge (p = 0.040). Appropriate toothpaste amounts were used in 30.2% of the cases, with the 2-6 year age group demonstrating the highest awareness (p < 0.001). Only 3.7% of parents correctly answered all three toothpaste-related questions. Overall, the knowledge score for toothpaste guidelines was highest in the middle-aged group (31.21%, SD = 28.66, p < 0.001).

Conclusion: A minority of parents are familiar with recommended early dental care practices and correct toothpaste usage. The findings emphasize the need to improve parental awareness from the very beginning of a child's development.

Objective: This study aimed to evaluate the effect of recombinant human bone morphogenic protein type-2 (rhBMP-2) on the alveolar ridge in the post-extraction socket in humans.

Method and materials: 20 subjects with 25 teeth of the maxilla were included (11 sockets in the control [blood clot] and 14 in the test group [rhBMP-2]). The teeth were minimally and traumatically extracted. CBCT images were obtained 2 (T0) and 120 (T1) days after extraction. The buccal bone wall height, palatal bone wall height, and alveolar area were compared between both groups, as well as the volumetric contraction through overlapped images (T1 - T0) using Mimics software. The data were compared using the Mann-Whitney test (P .05).

Results: The intragroup evaluation showed a significant buccal and palatal crest height resorption in the control group (P .05). In the intergroup assessment, the test group was superior to the control group in maintaining the average alveolar ridge area since the control group showed an area loss of approximately 39% between T0 and T1, whereas this reduction was approximately 15% in the test group (P .05).

Conclusion: It is possible to conclude that using rhBMP-2 after tooth extraction resulted in better socket preservation, maintaining 2.5 times greater bone availability in the alveolar ridge than that of the control group.