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目的评价单纯牙周基础治疗对苯妥英钠(PHT)所致药物性牙龈增生的治疗效果。方法选择佛山市禅城区向阳医院·禅城区口腔医院2011年1月至2013年6月因服用PHT导致牙龈增生的患者16例,在不停药亦不换药的情况下行牙周基础治疗,并于治疗前及治疗后1、3、6个月进行牙龈增生指数(GHI)、菌斑指数(PLI)、龈沟出血指数(SBI)、探诊深度(PD)等临床指标检查。结果单纯牙周基础治疗后1、3、6个月的GHI、PLI、SBI、PD各项临床指标逐步改善,牙龈炎症逐步减轻,牙龈增生状况持续好转;与治疗前基线相比,差异均有统计学意义(均P<0.05)。结论单纯牙周基础治疗对PHT所致药物性牙龈增生有效。     

The role of single immediate loading implant in long class IV Kennedy mandibular partial denture

Background: The treatment of long‐span Kennedy class IV considers a prosthodontic challenge. This study evaluated the integrity of principle abutments in long Kennedy class IV clinically and radiographically, when rehabilitated with conventional metallic partial denture as a control group and mandibular partial overdentures supported with single immediately loaded implant in symphyseal as a study group. Material and Methods: Twelve male patients were divided randomly allotted into two equal groups. First group patients received removable metallic partial denture, whereas in the second group, patients received partial overdentures supported with single immediately loaded implant in symphyseal region. The partial dentures design in both groups was the same. Long‐cone paralleling technique and transmission densitometer were used at the time of denture insertion, 3, 6, and 12 months. Gingival index, bone loss, and optical density were measured for principle abutments during the follow‐up. Results: A significant reduction in bone loss and density were detected in group II comparing with group I. Gingival index had no significant change (p‐value < 0.05). Conclusion: A single symphyseal implant in long span class IV Kennedy can play a pivotal role to improve the integrity of the principle abutments and alveolar bone support.     

Morphometric evaluation of changes in the alveolar bone and roots of the maxillary anterior teeth before and after en masse retraction using cone-beam computed tomography

Objective:To evaluate the morphometric changes in the alveolar bone and roots of the maxillary anterior teeth (MXAT) after en masse retraction with maximum anchorage (EMR-MA).Materials and Methods:The samples consisted of 37 female adult patients who had Class I dentoalveolar protrusion (CI-DAP) and were treated by extraction of the first premolars and EMR-MA. Using three-dimensional cone-beam computed tomography taken before treatment and after space closure, the maxillary central incisors (MXCI, N  =  66), lateral incisors (MXLI, N  =  69), and canines (MXC, N  =  69) were superimposed using individual reference planes. After alveolar bone area (ABA), vertical bone level (VBL), root length (RL), root area (RA), and prevalence of dehiscence (PD) were measured at the cervical, middle, and apical levels, statistical analyses were performed.Results:On the palatal side, ABA significantly decreased in all levels of MXAT (P < .001; middle of MXC, P < .01). MXCI and MXLI exhibited a greater decrease in the ratio of change in palatal ABA than did MXC (cervical, P < .01; middle and apical, P < .05; total, P < .001). Palatal/labial ABA ratios decreased in MXCI (cervical, middle, total, P < .001; apical, P < .05) and MXLI (cervical, P < .001; apical, P < .05). They showed greater amounts and ratios of change in VBL on the palatal side compared to the labial side (all P < .001). The palatal side showed more PD in the cervical area than did the labial side (MXCI and MXLI, P < .001; MXC, P < .01). Significant root resorption occurred in MXAT (RL and RA, all P < .001).Conclusions:During EMR-MA in cases with CI-DAP, ABA and VBL on the palatal side and RL and RA of MXCI and MXLI were significantly decreased.     

Doxycycline‐Loaded β‐Tricalcium Phosphate Release Following EDTA Root Surface Etching Improved the Clinical Outcomes in Chronic Periodontitis: An In Vivo Study

Background: The main objective of the present study is to quantify doxycycline (DOX) release from β‐tricalcium phosphate (β‐TCP) after EDTA root surface treatment. Methods: Thirty systemically healthy patients with ≥1 paired contralateral interproximal intrabony defect ≥4 mm deep along with an interproximal probing depth ≥6 mm and clinical attachment level ≥4 mm were randomized into two groups. Group 1 (G1) consisted of sites treated with open flap debridement followed by placement of DOX blended with β‐TCP (DOX‐β‐TCP), whereas group 2 (G2) sites were treated with flap surgery followed by the placement of DOX blended with β‐TCP after EDTA etching of the exposed root surfaces (DOX‐β‐TCP + EDTA). Samples of gingival crevicular fluid (GCF) were obtained 1, 3, 7, 14, and 21 days after surgery. Quantitative measurements of DOX were taken with high‐performance liquid chromatography. Clinical evaluation and follow‐up for 6 months were performed. Results: At 21 days, the DOX‐β‐TCP + EDTA–treated group showed a 194.7 µg/mL value. The DOX‐β‐TCP + EDTA–treated group retained more DOX during the periods of 3, 7, 10, 14, and 21 days than the DOX‐β‐TCP–treated group. Six months after therapy, DOX‐β‐TCP + EDTA–treated sites showed more significant clinical improvements compared to DOX‐β‐TCP–treated sites (P ≤ 0.05). Conclusions: EDTA root surface etching enhances DOX availability in the GCF following its release from β‐TCP as a drug carrier.     

Influence of preoperative dental procedures on the prognosis of patients with squamous cell carcinoma of the gingiva

Our aim was to investigate the prognosis of patients with squamous cell carcinoma (SCC) of the gingiva who had preoperative dental operations. We studied 102 patients who were being operated on for SCC of the gingiva with special reference to the effects of preoperative dental operations on the prognosis. Twenty-six patients had dental procedures such as tooth extraction, or incision, or curettage before they visited our hospital, while the remaining 76 had no such interventions. The percentage of patients with advanced T stage disease (T3 or T4) was higher among those who had interventions (17/26, 65%) than among those who had not (35/76, 46%). The difference was not significant. Histopathologically invaded nodes were detected in half the patients in the intervention group (13/26), while they were found in only 18/76 (24%) of those in the no intervention group (p < 0.02). The incidence of nodal metastases with extranodal spread was significantly higher in the intervention group than in the no intervention group (p < 0.05), and those in the intervention group were more likely to develop distant metastases than those in the other group (p < 0.001). The 5-year survival in the two groups was 65% and 92%, respectively (p < 0.01). Preoperative dental operations such as tooth extraction, incision, or curettage possibly lead to regional and distant metastases and therefore a poor prognosis in patients with SCC of the gingiva.     

An ex vivo assessment of gingivally offset lower premolar brackets

Abstract

Objectives: To compare the force to failure of standard premolar brackets to that of gingivally offset brackets and evaluate the site of bond failure between the two bracket types through the use of the Adhesive Remnant Index (ARI).

Design: An ex vivo study.

Setting: Dental Materials Science Laboratory, Dundee Dental School, Dundee.

Materials and methods: Forty extracted lower premolar teeth (caries free, extracted as part of orthodontic treatment, all donors living in a non-fluoridated area), divided into two equal size sample groups, as follows: Group 1: Victory Series^? (3M Unitek, Monrovia CA, USA) lower premolar brackets bonded to buccal surfaces with Transbond XT (3M Unitek, Monrovia CA). Group 2: Victory Series^? Gingivally Offset Bicuspid Brackets (3M Unitek, Monrovia CA) bonded to buccal surfaces with Transbond XT (3M Unitek, Monrovia CA). Force was applied in the occluso-gingival direction using an Instron Model 4469 Universal Testing Machine (Instron Ltd, High Wycombe, UK) operating at a cross-head speed of 0.5 mm/min and its value at failure determined. Following debond, the site of bond failure and ARI were recorded.

Outcome: Force to failure, site of bond failure and adhesive remnant index.

Results: The Weibull analysis gave higher values for the force to failure at 5% level (200 v. 159 N) and at all other levels of probability of failure for the gingivally offset bracket. The non-parametric survival analysis using Gehan–Wilcoxon tests with Breslow’s algorithm (p < 0.0001) showed significant difference in force to failure between bracket types. Chi-square tests showed no significant (p = 0.55) relationship between the site of bond failure and the bracket types.

Conclusion: Ex vivo testing suggests that there is a significant difference in the force to failure between gingivally offset and standard lower premolar brackets when force application is from an occluso-gingival direction. The site of failure (as given by the ARI) is insensitive to bracket types and force to failure.