Microcirculation of the healthy human gingiva

 The purpose of this study was to evaluate the microcirculation in healthy human gingiva. Forty-two adult volunteers with clinically healthy gingiva participated. The ages of this research sample ranged from 20 to 30 years. Periodontal conditions were evaluated and assessed by using the qualitative plaque index, gingival index, gingival bleeding index, tooth mobility, and laser Doppler flow-metry (LDF) on 12 maxillary and mandibular anterior teeth. The LDF data were recorded on the facial aspect of the free gingiva, interdental gingiva, attached gingiva, and alveolar mucosa of 12 maxillary and mandibular anterior teeth, utilizing an acrylic stent to stabilize the probe. This technique was then modified to circumvent contamination by saliva and gingival exudate. Blood flow in the maxillary anterior gingiva differed significantly from that in the mandibular anterior gingiva in interdental gingiva, attached gingiva, and alveolar mucosa, at P < 0.01. The maxillary anterior gingiva, at each point on the stent, showed significant differences in the mean LDF, at P < 0.01. For the mandibular anterior gingiva, the difference was significant only in the alveolar mucosa region. Received: November 10, 2000 / Accepted: January 23, 2002     

A clinical study of the width of the attached gingiva in the deciduous, transitional and permanent dentitions

This study involved 331 individuals who were without clinical evidence of gingival inflammation. The width of the keratinized gingiva and the depth of the gingival sulcus were measured on the mid-facial aspect of all teeth in each patient, using a calibrated, flat periodontal probe. The mean width of the attached gingiva did not show an increase from the deciduous to the permanent dentition. However, the width of the attached gingiva in the case of newly erupted permanent teeth was narrower than in the corresponding primary teeth. The widest zone of attached gingiva was found over the central and lateral incisors. The width of the attached gingiva decreased over the canine and the first premolar (and first primary molar). It then increased over the second premolar (and second primary molar) and the first molar. These variations were approximately the same in both the maxilla and the mandible, although there was a greater over-all width of attached gingiva in the maxilla than in the mandible. The tendency, in the permanent dentition, for the attached gingiva to increase in width with age was related to a concomitant decrease in sulcus depth.     

显微牙周外科技术在种植体周附着龈增宽术中的应用

目的 探讨显微牙周外科技术在种植体附着龈增宽术中的临床应用效果。方法 对20例种植体周附着龈不足或缺失的患者,采用显微牙周外科技术增宽种植体周的附着龈。术后观察游离龈瓣的存活状态,并记录术前、术后即刻、术后1年时附着龈的宽度,计算术后1年附着龈的收缩率。结果 20例患者的游离龈瓣均存活,术后1年附着龈宽度为（3.05±0.44）mm,与术前相比增加了（2.56±0.31）mm,与术后即刻相比减小了（2.13±0.28）mm,附着龈收缩率为41.22%±5.04%。结论 显微牙周外科技术应用于附着龈增宽术可获得较高的成功率,能较好地提高种植体周附着龈的质量。     

Morphological changes in the attached and keratinized gingiva and gingival sulcus in the mixed dentition period

Abstract A longitudinal study was undertaken to examine the changes in the sulcus probing depth, keratinized and attached gingiva during the mixed dentition period. 54 children aged 7 to 9 years at the first examination were examined twice, with an interval of 5 years. Sulcus probing depth and keratinized gingiva were examined at the buccal aspect of the incisors, and either right or left cuspids and posterior areas. The width of the attached gingiva was obtained by substracting the probing depth from the width of the keratinized gingiva. When compared to primary predecessors, the permanent teeth had a deeper probing depth, narrower attached gingiva and at the maxillary teeth, a wider keratinized gingiva. When a pennanent tooth was present at both examinations, there was a significant increase in width of the attached gingiva with a corresponding decrease in probing depth, and a slight beginning of an increase in the width of keratinized gingiva. Previous and the present findings indicate that during the early years after eruption of the permanent tooth, an increase in width of the attached gingiva takes place, without occlusal migration of the marginal gingiva whereas, at later stages, this coronal migration takes place, concomitant to tooth eruption.     

生物导向型预备技术的研究进展

稳定固定义齿及种植义齿牙龈边缘的位置，避免发生牙龈退缩是维持美学区修复长期疗效最关键的问题之一。Loi于2008年提出了一种生物导向型预备技术，将其应用于固定义齿及种植义齿修复中可以使修复体周围牙龈组织增厚，可对牙龈边缘的稳定性起重要作用。本文对生物导向型牙体预备技术在固定修复及种植义齿修复中的应用及疗效评价做一综述。     

Gingival tissue-produced inhibition of platelet aggregation and the loss of inhibition in streptozotocin-induced diabetic rats

Addition of medium incubated with normal rat gingival tissue to platelet-rich plasma inhibited ADP-induced platelet aggregation. The ability of rat gingiva to produce activity inhibiting platelet aggregation was enhanced by the addition of arachidonic acid. Diabetic rat gingiva failed to inhibit platelet aggregation but did produce the anti-platelet aggregating activity in the presence of arachidonic acid. Indomethacin blocked the production of anti-platelet aggregating activity. There was no difference in conversion of [1-¹⁴C]arachidonic acid to prostaglandins by normal and diabetic rat gingiva. These results suggest that an arachidonic acid metabolite released from gingiva during incubation inhibits platelet aggregation, and the synthesis of the metabolite is impaired in diabetic rat gingiva. A decrease in availability of arachidonic acid may be a causal factor of the defect in diabetic rat gingiva.     

Increased fibrinolytic activity in the inflamed gingiva of beagle dogs.

The fibrinolytic activity originated by activation of plasminogen was found to be greater in the inflamed gingiva than in the normal gingiva. The activator of plasminogen present in the normal and inflamed gingiva of the beagle dog was demonstrated histochemically. Plasminogen activator was found adjacent to the crevicular epithelium and blood vessels.     

自体游离硬腭黏膜移植在牙种植体周附着龈增量中的应用评价

目的：应用自体游离硬腭黏膜移植,进行种植体周附着龈增量,评价其临床效果。方法：选择21例种植术后种植体周附着龈严重不足患者．在种植术后1个月行自体游离硬腭黏膜移植,术后6个月测量附着龈宽度增加量。采用SPSS11．5软件包中的配对t检验分析手术前、后的附着龈宽度值变化。结果：种植体周附着龈宽度术后6个月平均增加量为（3．77±0．43）mm,手术前、后比较,差异显著（P〈0．05）。结论：自体游离硬腭黏膜移植是种植体周附着龈增量的有效方法。     

根向复位瓣在附着龈宽度不足患牙的牙冠延长术中的应用

目的：：评价根向复位瓣在附着龈宽度不足的患牙牙冠延长术中的应用效果。方法：纳入需行牙冠延长术但附着龈宽度不足的患牙17颗,术中采用根向复位瓣法对牙龈瓣进行复位,记录手术前和术后6个月龈缘到牙体断端的距离、附着龈的宽度等指标并进行比较和评价。结果：术前17颗患牙牙体缺损边缘均位于龈下,术后6个月16例(94.11%)缺损边缘均暴露在龈缘冠方,龈缘根向位移距离(3.88±0.49) mm;17颗患牙附着龈宽度术前为(2.35±0.61) mm,术后6个月为(2.65±0.49) mm(P>0.05)。结论：牙冠延长术可以有效暴露牙体缺损边缘,为牙体缺损创造修复条件,避免切除过多角化龈导致附着龈宽度变窄。     

Significance of the width of keratinized gingiva on the periodontal status of teeth with submarginal restorations

The purpose of this clinical study was to evaluate the periodontal condition of teeth having submarginal restorations associated with either narrow or wide zones of keratinized gingiva. Fifty-eight teeth in 26 individuals were selected and then divided into two groups according to the width of the keratinized gingiva at the midfacial aspect of the tested tooth. Group I consisted of 30 teeth with greater than or equal to 2.0 mm, and Group II consisted of 28 teeth with less than 2.0 mm of keratinized gingiva. Each group was equally subdivided into subgroup "A" having teeth with a full coverage, subgingival type of restoration for at least 2 years, and subgroup "B" representing contralateral homologous teeth, in the same individual, with no subgingival restoration. Clinical examination of individual teeth included determination of plaque and gingival indices, gingival fluid, probing depth, bleeding tendency and bone level. Data were subjected to statistical analysis using the Student t test and a two-way analysis of variance to determine any significant differences in variables between teeth with and without subgingival restorations, in narrow and wide zones of keratinized gingiva. The findings were: (1) teeth with subgingival restorations and narrow zones of keratinized gingiva showed statistically significant higher gingival scores than teeth having submarginal restorations with wide zones of keratinized gingiva. (2) Teeth without subgingival restorations showed no statistical difference between narrow and wide zones of keratinized gingiva (P greater than 0.05).     

Historical quantification of the biological effects of estradiol benzoate on the gingiva and gential mucosa of castrated rabbits

The biological effects of castration and estrogen replacement therapy were studied in the gingiva of adult female rabbits. Measurements were made to hislologically quantitate changes induced by estrogen on the gingiva when compared to the well established effects which occur in the reproductive tract of the female rabbit. Parentally administered esradiol benzoate resulted in significant changes within the uterus and vagina. No corresponding changes were detected in the gingiva.     

Morphological changes in the tissues of the prosthetic field with the use of different designs of metal ceramic bridge dentures]

The results of experimental morphologic studies carried out in 23 dogs evidence that the status of the denture bed tissue beneath a whole-cast bridge cermet denture depends on the tightness of the denture adhesion to the gingival mucosa. If the denture poorly adheres to its bed, no marked changes in the structural components of the gingiva and the underlying bone support are detectable. If the denture adheres tightly to the gingiva, marked inflammatory dystrophic and destructive changes develop both in the gingiva and in the alveolar crest bone tissue. A complex of structural changes in the epithelium, connective tissue base of the gingival mucosa, and alveolar bone crest were traced. The results evidence that inflammatory dystrophic changes in the gingiva augment and result in the development of erosive ulcerative elements in the gingiva in case of a prolonged tight adhesion of the denture to the denture bed; sometimes decubital ulcers may develop in the gingiva. The resorptive processes take place in the underlying bone tissue, causing like smooth resorption of bone matter or to lacunar resorption. Diffuse rarification of bone tissue is also typical of such cases. Excessive pressure of the denture body in case of its tight adhering to denture bed seems to be detrimental not only for the epithelium, but for deeper structures of the gingival mucosa and the underlying bone structures as well.     

The width of clinically-defined keratinized gingiva in the mixed dentition

Some authors have noticed a clear decrease of the width of keratinized gingiva when they compared the width over deciduous and newly erupted permanent teeth. The aim of this cross-sectional study was to assess the width of keratinized gingiva over permanent and deciduous teeth present in 6 to 11-year old children in an urban environment. The greatest width of keratinized gingiva was found over deciduous canines and permanent incisors. When comparing the width of keratinized gingiva over deciduous canines and molars and permanent first incisors and first molars, statistically significant differences were found only between 6- and 11-year-old groups. The findings do not seem to support previously published data, but do suggest that periodontal mucogingival surgery is not needed before the patient reaches the adult age, since there is a tendency of an increase of the width of keratinized gingiva.     

On the relationship between crown form and clinical features of the gingiva in adolescents

Abstract The purpose of the present study was to examine the relationship between the form of the crowns in the maxillary front tooth segment and (1) a group of morphological characteristics and (2) the thickness of the gingiva. 108 subjects devoid of symptoms of destructive periodontal disease were examined regarding, e.g., probing depth, thickness of the free gingiva, width of the keratinized gingiva and the contour of the marginal gingiva. From clinical photographs of the maxillary front tooth region, the width (at the apical third – CW) and the length (CL) of the crowns of the 6 front teeth were determined. A CW/ CL-ratio was calculated for each tooth and averaged for each tooth region. The individual mean CW/CL-ratio values for the central incisors were ranked. After correction for incisal attrition, the 10 subjects ranked highest and the 10 ranked lowest were selected as having either a long-narrow (group N) or a short-wide (group W) form of the crown of the tooth. The data for each of the examined parameters were averaged for each tooth region in each subject and mean values for subjects in groups W and N were compared using the Student t-test. Stepwise multiple regression analysis, including data from the whole sample, was performed for each tooth region with the thickness of the free gingiva as the dependent variable. The results from the analyses demonstrated that individuals with a long-narrow form of the central incisors displayed, compared to individuals with a short-wide crown, form (i) a narrow zone of keratinized gingiva, (ii) shallow probing depth, and (hi) a pronounced “scalloped” contour of the gingival margin. There was no significant difference between groups N and W with respect to the thickness of the free gingiva. The CW/CL-ratio data revealed that a certain form of the crowns in the central incisors was accompanied by a similar form in the lateral incisor and canine tooth region. The regression analyses demonstrated that the thickness of the free gingiva in central incisors was significantly related to (i) the width of the keratinized gingiva, (ii) the buccolingual width of the crown and (iii) the presence of an interproximal gingival groove. In lateral incisors, the thickness of the free gingiva was associated with the probing depth at the buccal surface. No single variable was significantly related to the thickness of the gingiva in canines.     

Scanning electron microscopy of the epithelium-connective tissue interfacein human gingiva

The morphological characteristics of the interface between epithelium and connective tissue in normal human gingiva were examined by scanning electron microscogy after separation of epithelium and connective tissue by maceration in sodium bromide solution. Separated crevicular epithelium showed dispersed arcade-shaped pits corresponding to long conical connective tissue papillae. In the epithelium and connective tissue of the free gingiva, horizontal ridges ran parallel to the gingival margin. At the transition from free gingiva to attached gingiva, short conical connective tissue papillae arose from horizontal connective tissue ridges. Toward the alveolar mucosa these papillae increased in number, forming a honeycomb pattern on the separated epithelial surface.     

Oxygen sufficiency in the gingiva of smokers and non-smokers with periodontal disease

BACKGROUND: Epidemiological studies have demonstrated deteriorating effects of smoking on periodontal tissue. The aims of this study were to compare oxygen saturation of hemoglobin in the gingiva (GSo2) of smokers and non-smokers and to evaluate the chronic effect of smoking on gingival oxygen sufficiency. METHODS: GSo2 was determined using tissue reflectance spectrophotometry in 110 papillary gingival sites of 62 smokers and 100 sites of 60 non-smokers. RESULTS: No significant difference was found in GSo2 between smokers and non-smokers. In the model of ANOVA with covariates, age (P= 0.0048) and probing depth (P= 0.0012) had significant effects on GSo2. No significant effect was found in either smoking status (P= 0.3557) or the modified gingival index (MGI) (P= 0.3824). The interaction effect between smoking status and the MGI was highly significant (P = 0.0003) indicating that the effect of smoking status on the GSo2 should be compared at each level of the MGI score. GSo2 in healthy gingiva was significantly lower in smokers than non-smokers (P = 0.0014), while smokers showed higher GSo2 than non-smokers in moderately inflamed gingiva (P = 0.0356). The GSo2 in inflamed gingiva was significantly decreased compared with healthy gingiva in non-smokers (P = 0.0044), while smokers showed no significant difference between healthy and inflamed gingiva (P= 0.2772 to 0.8665). GSo2 in smokers was consistently and significantly lower than that of healthy gingiva of non-smokers (P = 0.0391 to 0.0004). CONCLUSIONS: Smokers exhibit possibly lower function of oxygen sufficiency in healthy gingiva and reduced ability to adapt the function in inflamed gingiva than non-smokers. This suggests that smokers have functional impairments in the gingival microcirculation.     

The depth of the vestibular fornix in the mandibular anterior region in health.

Using a radiographic technique, the depth of the vestibular fornix in the lower anterior region was determined for 100 periodontally healthy subjects. The width of attached gingiva was measured clinically. The vestibule in the mandibular anterior region was found to be approximately uniform in depth for each individual from canine to canine, being reduced where there were frenal and muscle attachments. The depth, measured from the gingiva to mucobuccal fold, varied from 2.5 to 11.5 mm; and. measured from the crest of the lip to mucobuccal fold, varied from 10 to 29 mm. The proportion of the vestibule, measured from gingiva to mucobuccal fold, occupied by attached gingiva, varied from a mean of 34% in the canine region, to approximately 60% in the lateral incisor region, and to approximately 55% in the central incisor region. The minimum depth of the vestibule determined was 2.5 mm, and this was associated with a zone of attached gingiva 1 mm wide. Considering that all subjects in this study were periodontally and gingivally healthy, it would appear that satisfactory periodontal and gingival health may be maintained even where the vestibule is shallow.     

Long-term therapeutic results following the application of free mucogingival autografts

For the purpose of enlargement of the attached gingiva and depending of the oral vestibule, as well as of the elimination of coronally inserted frenula and mucosal folds, we used free mucogingival autografts. The study included 53 patients of both sexes and different ages, with some of the abnormalities regarding the attached gingiva and the surrounding tissues. We revealed that inherited or acquired abnormalities regarding the attached gingiva and the alveolar mucosa could be successfully corrected by free mucogingival autografts. This is particularly true in the elimination of abnormalities related to the narrowly attached gingiva, shallow vestibule and inadequately inserted frenula and mucosal folds. By graft application we were able to enlarge of the attached gingiva in our patients by 5.41 mm in average. At the same time vestibular depth in our patients was distinctly increased. This was also statistically confirmed (p less than 0.001).     

Influence of free gingival grafts on the health of the marginal gingiva

Abstract In order to evaluate the effect of increasing the width of inadequate attached gingiva on the health of the marginal gingiva, 12 free gingival grafts were performed on 12 patients with less than 1.0 mm of attached gingiva on homologous contralateral pairs of mandibular teeth. A baseline examination, which included measurements of plaque, gingival exudate, sulcus bleeding, sulcus probing depth and width of attached gingiva, was done before surgery. One week after surgery, plaque was eliminated mechanically on the test and control sides. All measurements were repeated 7 and 14 weeks after surgery. During the week following the first postsurgical examination, individual oral hygiene instruction was given until the patient could show plaque-free test and control sites. The width of the attached gingiva increased significantly on the side where the grafting was performed (test side). The only other significant changes observed during the experiment were a decrease of the mid-buccal plaque index on the test side during the first 7 weeks following surgery and a decrease of the buccoproximal plaque index on the test and control sides during the total experimental period (14 weeks). None of the other clinical parameters measured showed significant differences when test and control sites were compared or when the same sites were compared longitudinally.     

A clinical comparison of the effect on the gingiva of the Prophy-Jet and the rubber cup and paste techniques

This clinical trial compared the effect on the gingiva of the Prophy-Jet and the rubber cup and paste techniques of stain and supragingival plaque removal. Twenty-one human subjects with healthy gingiva or slight gingivitis participated. A split mouth design was used. The Prophy-Jet caused a statistically significant increase (P less than 0.05) in gingival irritation immediately posttreatment, but the differences were not deemed clinically significant. There were no statistically significant (P less than 0.05) or clinically significant differences in the effect on the gingiva between the two techniques at 7 and 21 days posttreatment. There was no lasting difference in gingival trauma between the two methods of stain and supragingival plaque removal in subjects with healthy gingiva or slight gingivitis.