光学相干层析技术用于早期龋检测的研究进展

早期发现龋损病变并进行及时正确地干预可以逆转龋病的进程,最大限度地保存牙齿,减少创伤性治疗;因此,龋病的早期准确诊断就显得非常重要。目前,临床上使用的常规检测龋病的方法无法客观、有效地检测早期龋,更不能对龋损进程进行定量监测,这就往往使患者丧失了保守治疗的最佳时机;因此,迫切需要安全、准确、可量化的技术来检测早期龋并对治疗干预措施进行监控。近年已开发出一系列检测早期龋的无创、定量检测新技术,本文就光学相干层析技术(OCT)用于检测早期光滑面釉质龋、早期牙骨质龋、早期窝沟龋等方面的研究作一综述。     

激光龋齿探测仪探测窝沟龋的界值研究

目的研究激光龋齿探测仪(DIAGNOdent,DD)诊断乳、恒牙窝沟龋的界值范围。方法收集离体磨牙、乳磨牙,清洁,用DD探测面可疑点荧光值,沿该点切开,在体视显微镜下阅片,以镜下所得龋损分级结果作为参照,分析DD对应龋损各阶段的荧光值(d值)范围,即DD界值,并评价按这一标准对龋病的诊断与临床磨开后诊断的一致率。结果DD探测磨牙窝沟龋,d值为0时显示无龋损,1～33之间显示龋损局限在釉质1/2或者正常,大于45显示龋损已超过釉质1/2;DD探测乳磨牙窝沟龋:d值为0时同样显示无龋损,大于25显示龋损已超过釉质1/2。且按实验所得乳磨牙龋病的DD界值标准诊断与临床磨开后的诊断一致率较好。结论DD探测龋病时,一个适当的界值标准可以很好地辅助临床诊断龋病。     

儿童龋病管理

龋病是临床上最为常见的儿童口腔疾病,儿童龋病在我国具有患病率高、治疗率低的特点。近年来,随着对龋病认识的日趋深化以及材料和技术的不断进步,儿童口腔医学不仅仅关注儿童龋病的治疗,开始更多地强调对其进行早期预防、诊断和干预,微创理念亦贯穿儿童龋病预防和诊疗的全过程。文章从对龋病发生发展的再认识出发,就儿童龋病风险评估和管理以及如何治疗儿童龋损做一介绍。     

早期釉质龋表层形成的化学机理

典型的牙釉质龋损均有一脱矿程度较深层组织轻的表层,再矿化可能是该表层形成最主要的化学机理,正常釉质表层固有的结构特点和特殊理化性质也起一定作用。研究早期釉质龋损表层形成的化学机理不仅是了解龋病发生动力学的重要内容,而且为临床防龋和治疗早期龋提供理论依据。     

儿童龋病管理

 龋病是临床上最为常见的儿童口腔疾病，儿童龋病在我国具有患病率高、治疗率低的特点。近年来，随着对龋病认识的日趋深化以及材料和技术的不断进步，儿童口腔医学不仅仅关注儿童龋病的治疗，开始更多地强调对其进行早期预防、诊断和干预，微创理念亦贯穿儿童龋病预防和诊疗的全过程。文章从对龋病发生发展的再认识出发，就儿童龋病风险评估和管理以及如何治疗儿童龋损做一介绍。     

不同牙龋病状况患者龈上菌斑及龋损组织微生物多样性分析

目的： 探讨不同龋病状况患者龈上菌斑及龋损组织微生物的组成特点及多样性差异。方法： 随机双盲法选择2019年1月—12月于西安医学院第一附属医院口腔科确诊的龋病患者33例（轻度、中度、重度各11例）,无龋病健康者10例。收集龈上牙菌斑和龋损组织,采用细菌DNA测序方法对细菌16S rRNA-cDNA高可变区进行测序,比较各组微生态种属和相对丰度。采用SPSS 23.0软件包对数据进行统计学分析。结果： 与无龋组相比,龋病组龈上菌斑、龋损组织中微生物含量和丰富度均显著降低（P<0.05）。轻、中、重度组患者龋损组织微生物主要为拟杆菌门、螺旋体门、变形菌门、梭杆菌门、厚壁菌门、放线菌门,各组菌属比例有显著差异（P<0.05）。轻、中、重度组患者龈上菌斑微生物主要有21种,其中,梭杆菌、科里亚细菌、奈瑟菌目、放线菌目、乳杆菌目占比高,其他均小于1%,各组5种菌属比例无显著差异（P>0.05）。结论： 龋病的发生由多菌种所致,且为多种细菌的共同作用。不同龋病状况患者龈上菌斑及龋损组织微生物丰度有显著差异,随着龋病的发生,微生物的多样性下降。     

微创牙科学:文献回顾与最新进展

微创牙科学是指采用生物学方法而不是传统的牙体手术处理龋病,以最大限度地减少对牙体结构的破坏。这种新的龋病处理方法,将过去强调的视龋损为“洞”而反复充填的理念,转变为视龋损为口腔生态失衡而促使生物膜产生生物学变化。微创牙科学的目的在于阻止龋病进程,然后修复缺失的牙体结构和功能,最大限度地发挥牙体的愈合潜能。微创牙科学的处理方法可概括为3个步骤:(1)判定患者的患龋风险;(2)再矿化,即防止龋损形成并逆转未形成“洞”的浅龋;(3)修复,即控制龋活性,使愈合潜能最大化并修复龋损。龋病并非仅仅是牙体脱矿,而是一个因生物膜与牙界面生态和化学平衡失衡而致的反复的脱矿过程(生态菌斑学说)。饮食和生活方式(尤其是碳水化合物的摄入频次)、饮水、吸烟是导致生物膜生态和致病性的重要因素。椅旁评价菌斑和唾液的方法的问世,使得龋病危险评估和监测患者的顺从性成为可能。唾液的再矿化特性,可以通过使用能够释放Ca2 、P5 、F1-的再矿化剂(CPP-ACPandCPP-ACFP)而予强化。使用某些化学制剂(氟、氯已定和木糖醇),可改变菌斑的致病性。采用微创治疗方案,可修复早期龋损,增进患者的理解力和顺从性。本文从3个方面,详细论述了微创牙科学的概念、理论基础和操作方法。     

早期釉质龋表层形成的化学机理

典型的牙釉质龋损均有一脱矿程度较深层组织轻的表层，再矿化可能是该表层形成最主要的比学机理，正常釉质表层固有的结构特点和特殊理化性质也起一定作用。研究早期釉质龋损表层形成的化学机理不仅是了解龋病发生动力学的重要内容，而且为临床防龋和治疗早期龋提供理论依据。     

预防性Dyract flow 流动复合体充填窝沟龋的临床效果

目的：观察评价Dyract flow流动复合体用于窝沟可疑龋、初龋预防性充填的临床疗效。方法：对145例7～24岁患者的牙合面窝沟龋在磨除龋损的牙体组织后，用Dyract flow流动复合体对龋损部位及未龋损的窝沟区域作预防性充填封闭术，对侧同名牙或邻牙也有窝沟龋者用银汞合金充填作对照。结果：随访4年后发现该方法充填材料保留率较高，能有效阻止龋病的进一步发展。其龋病及继发龋发病率与对照组有显著性差异。但充填材料保留率的远期效果不如银汞合金，在3、4年时有统计学差异。结论：预防性Dyract flow流动复合体充填术可作为治疗窝沟龋的银汞合金的替代治疗方法之一，长期随诊进行补涂效果则更佳。     

龋损、龋蚀、龋坏、龋变、龋患

牙齿因龋病而致牙体硬组织损坏 ,外文称为carieslesion ,中文译名有龋损、龋蚀、龋坏、龋变、龋患。据英汉医学词汇 ,lesion译为损害 ,因此建议carieslesion译为龋损 ,其他龋蚀、龋坏、龋变、龋患均废弃不用 ,以免混淆龋损、龋蚀、龋坏、龋变、龋患@史俊南$第四军医大学口腔医学院!陕西西安710032     

Therapeutic use of sealants for incipient or early carious lesions in children and young adults.

Although the overall caries rate has declined significantly in the past decade, recent studies have shown that caries in occlusal pits and fissures continues to be a significant problem in adolescents and young adults. Radiographic and bacteriologic studies of sealed carious teeth were originally designed to allay the profession's concerns about continued progression of the carious process. These studies have demonstrated that caries is inhibited and may in fact regress under intact sealants. The changes in patterns of caries incidence and the positive results of the sealant studies suggest that alternative approaches to the treatment of incipient or early occlusal caries should be considered. In addition to the radiographic and bacteriological studies of sealed carious teeth, studies on retention over carious pits and fissures, wear, cost effectiveness and changing attitudes of dentists indicate that sealing incipient or early carious lesions is a viable alternative to restoration with amalgam.     

Clinical evaluation of Carisolv in the chemico-mechanical removal of carious dentin.

The Chemo-mechanical caries removal technique involves the application of chemical agents, to cause a selective softening of the carious dentine and facilitate removal by gentle excavation. Carisolv is one such new chemical agent used in this minimal invasive technique of carious dentine removal. The present study was, therefore, undertaken to evaluate the efficacy of Carisolv in the chemo-mechanical removal of carious dentine, the time taken for caries removal, the perception of the treatment by the patient, and to evaluate the restorations, radiographically. Accordingly, fifty primary and permanent molars with dentinal carious lesions were excavated using this technique of caries removal. The chemo-mechanical caries removal technique using Carisolv proved to be an effective atraumatic treatment modality with potential interest for use in clinical pediatric dentistry.     

Caries diagnosis using a laser fluorescence system--observation of autofluorescence of dental caries--

The purpose of this study was to evaluate the usefulness of autofluorescence of carious lesions on caries diagnosis. The observation of the micromorophology of caries lesions was conducted using a confocal laser scanning microscope, a fluorescence microscope and a WDX type electron probe X-ray microanalyzer. Observation of autofluorescence under Cy5 and UV fields showed clearly specific images of autofluorescence in the carious lesion. However, observation of autofluorescence under FITC field showed images of autofluorescence with unclear boundaries in the carious lesion. EPMA images showed decreases in Ca and P in the carious areas. As a result of the observation of autofluorescence and the EPMA images in the carious lesion, a correlation was noted between autofluorescence under the Cy5 field as the laser fluorescence apparatus for caries diagnosis and demineralized areas. The usefulness of autofluorescence of carious lesion on caries diagnosis was suggested.     

The effect of lesion size, restorative material, and film speed on the detection of recurrent caries

The purpose of this investigation was to study the effect of the size of carious lesions, radiographic density of composite and amalgam restorative materials, and film speed on the radiographic detection of simulated recurrent caries. Radiographs were made of extracted premolars with either large or small recurrent carious lesions simulated adjacent to Class II amalgam or composite restorations with both E-speed and D-speed intraoral film. For each restorative material, teeth that had no simulated caries were compared with teeth that had small and large simulated caries. Recurrent caries is detected best when the lesion is adjacent to radiopaque composite restorations, and detection is poorest when the lesion is next to radiolucent composite restorations. Large carious lesions are identified correctly more often than small lesions, although many lesions are not detected at all, especially those adjacent to radiolucent composite materials. There is no difference between E-speed and D-speed film for the detection of recurrent carious lesions.     

Caries profunda problems in past and at present

The development of profound caries therapy in relation to soft carious dentin and carious changed dentin is summed up. Because of its pulpitis preventing meaning profound carious therapy demands the scientific disputation in presence and future.     

Rationale for the partial removal of carious tissue in primary teeth

No consensus exists regarding the need for a second clinical session to remove carious dentin that remains in the pulp wall after partial caries removal. The purpose of the present article was to review studies that evaluated the effect of partial caries removal as provisional or definitive treatment on the dentinal microflora, the pulp response, or the progression of carious lesions in primary teeth. The results showed that partial caries removal performed in 1 session is more advantageous than removal in stages over 2 visits. This treatment, in addition to permitting the inactivation of caries lesions and reducing cariogenic micro-organisms in dentin, reduces the risk of pulp exposure caused by cavity reopening and excavation of remnant carious dentin. The favorable outcomes of partial caries removal in a single session support the indication of this modality as a definitive alternative restorative treatment for the primary dentition.     

Efficiency of the polymer bur SmartPrep compared with conventional tungsten carbide bud bur in dentin caries excavation

SmartPrep is a rotating instrument for dentin caries excavation made from a special polymer. The manufacturer's product information stated that SmartPrep removes carious dentin selectively. This in vitro study compared the efficiency of SmartPrep with conventional tungsten carbide bud burs. Fifty extracted teeth were split in the center of a carious lesion. The 100 specimens were randomly divided into five groups. Five dentists were asked to excavate 10 teeth each: one half with SmartPrep and the corresponding half with conventional bud burs. The time needed for the caries excavation was measured. Subsequently, histological specimens were produced from all cavities and analyzed by light-microscope after Mallory-Azan-staining. The thickness of the remaining caries was measured (< 1 mm or > 1 mm). The time expended was analyzed using the paired t-test. The results were analyzed for the remaining caries and thickness of the carious layer for every tooth, using the non-parametric Wilcoxon test for combined random samples. A binary logistical regression was performed to determine the influence of the three variables (tooth, sections or bur) on the criteria "caries" or "carious layer thickness (> 1 mm)." The average time to excavate a cavity with SmartPrep was 208.1 seconds, and it was 228.32 seconds with conventional bud burs. The difference between the recorded times was not statistically significant (p > 0.05). In 37 of 50 teeth, the number of carious sections was higher in the SmartPrep group than in the bud bur group. In nine teeth, the quantity of carious sections was higher in the bud bur group than in the SmartPrep group. Four teeth showed no difference in the number of carious sections. The results were statistically significantly different (p < 0.001). In 30 teeth, the number of carious sections with a carious layer thicker than 1 mm was higher in the SmartPrep group compared with the bud bur group. In nine teeth, the number of carious sections was higher in the bud bur group than in the SmartPrep group. Eleven teeth showed no difference in thickness of the carious dentin layer. These results were statistically significantly different (p = 0.003). Binary logistical regression showed that only the variable "bur" (bud bur or SmartPrep) influenced the results concerning the criterion "caries" (p < 0.001).     

The caries process and its effect on the pulp: the science is changing and so is our understanding

The understanding of the caries process and its effect on the pulp is presented in the context that caries does develop in various rates of progression. Early in the caries process, the pulp reflects changes within lesion activity. Thus, the early pulp response is reversible. Later, the rate of caries progression is reflected by the quality of the tertiary dentin. Slowly progressing lesions create tertiary dentin resembling normal tubular dentin. Rapidly progressing lesions lead to the production of a tubular dentin or complete absence of tertiary dentin, as well as pulp necrosis and apical pathology Finally, the nature of the untreated deep carious lesion is on ecosystem that might undergo significant changes. The untreated lesion is temporarily converted from an active and closed lesion environment into one that is open and slowly progressing. The analysis of untreated carious lesions has transformed the treatment philosophy of deep carious lesions.     

An in vitro investigation of penetration depth of dentine bonding agents into carious dentine

The aim of the present in vitro study was to determine the penetration depth of dentine bonding agents into carious dentine as a possible strategy in caries treatment of deep lesions. Forty-eight extracted carious teeth were used for the experiments and divided in four groups. In a split-tooth design, one half of each tooth was treated without caries excavation, and the second half after caries excavation. In group 1 the teeth were treated with Prime & Bond 2.0 without phosphoric acid etching, and in group 2 with phosphoric acid etching. In group 3, the teeth were treated with All-Bond 2 without phosphoric acid etching, and in group 4 with phosphoric acid etching. Bonding agents were marked with an orange dye prior to application. The composition of the bonding agents had no significant influence on penetration depths. The mean thickness of the outer, necrotic caries zone in unexcavated specimens was 117 microm (+/-126). Bonding agents penetrated significantly deeper into unexcavated carious dentine (mean 124 +/- 76 microm) compared with excavated dentine (11 +/- 14 microm) and sound dentine (3 +/- 4 microm). Acid etching significantly reduced the thickness of the outer caries zone, and the penetration depth of the bonding agents into unexcavated carious specimens by approximately 50%, and increased it into sound dentine. The results indicate that dentine bonding agents could completely penetrate the unexcavated outer carious dentine in 90% of specimens. Further studies are required to determine whether further caries activity is arrested after treatment with dentine bonding procedures.     

The relationship between the color of carious dentin stained with a caries detector dye and bacterial infection

This in vitro study aimed to design a method for the objective evaluation of carious dentin using numerical values. This study also investigated the relationship between the color of carious dentin stained with a caries detector dye using this objective method and the rate of bacterial detection as detected by a polymerase chain reaction (PCR). In 15 molars with occlusal dentin caries and three extracted sound molars, dentin was removed in multiple steps with 300 microm removed each step. Before and after every removal, images of a color-matching sticker and carious surfaces stained with a caries detector dye were acquired simultaneously using a CCD camera and dentinal tissue samples were removed with a round bur. Next, corrected L*, a* and b* values of the carious surfaces (CIE 1976 L*a*b* color system) were calculated from the color changes of the stickers in the images. In addition, bacterial DNA in the dentinal tissue was detected by PCR. From evaluations of the receiver operating characteristic curves for the L*, a* and b* values, the L* value was determined to be a more useful parameter than a* or b* for detecting bacterial infection using the caries detector dye. The bacterial detection rates of carious dentin decreased as the L* values of carious dentin stained with the dye increased. When the L* values were more than 60, the dentin had no bacterial infection. This study clarified the relationship between the colors of lesions stained with a caries detector dye and the rates of bacterial detection.