Histologic comparison of light emitting diode phototherapy-treated hydroxyapatite-grafted extraction sockets: a same-mouth case study

BACKGROUND: The stimulating effect of red and near-infrared (NIR) laser phototherapy on bone regeneration and growth has been shown in a number of in vitro and animal studies. However, the effect of NIR phototherapy on the bone regeneration of hydroxyapatite (HA) -treated extraction sockets has not been previously demonstrated. MATERIALS AND METHODS: An investigational Biolux extraoral light emitting diode phototherapy device was used daily for 21 days postextraction and socket grafting with HA (Osteograf LD300) unilaterally. Bone regeneration of the phototherapy-treated and nontreated side was compared in same-mouth extraction sockets. RESULTS: Histologic evaluations showed enhanced bone formation and faster particle resorption associated with the phototherapy-treated socket graft compared with the non-phototherapy-treated socket. CONCLUSIONS: The accelerated bone healing in the phototherapy-treated HA socket graft may provide faster implant placement compared to non-phototherapy-treated socket grafts.     

Experimental study of osseointegrated dental implants placed into fresh extraction sockets in dogs]

OBJECTIVE: To investigate the better way in treating bone defects around implants. METHODS: 12 mongrel dogs, pure titanium implants were immediately inserted in the mesial roots of the second, third and fourth mandibular premolar sockets. The defects around implants were separately filled with demineralized freeze-dried bone allograft (DFDBA), demineralized freeze-dried allocancellous in combination with bBMP (bBMP compound bone) and nothing. RESULTS: Histologic observation showed that bone defects around implants were substituted by new bone in DFDBA group at 12 weeks and in bBMP compound bone group at 8 weeks, and also the osseointegration were obtained between implants and bone, but bone defects were only filled about 3/5 in no graft group at 12 weeks. CONCLUSION: Immediate implants could obtain good osseointegration if the defects around implants were treated properly and the right technique was used, and also the use of bBMP compound bone could promote obviously bone formation in defects around implants.     

A histological study of cartilage autografts and allografts placed in dental sockets of rats.

Seventy-two albino rats were used in order to analyze what occurs when fresh cartilage autografts and allografts are placed into dental extraction sockets. The rats were killed from 1 to 120 days, and the following conclusions were made: autografts were better accepted; there was a tendency to eliminate graft material as healing took place (this was more pronounced in the allograft group); there was appositional growth of the grafts in both graft groups, although this was more pronounced in the autogenous group; the bone trabeculae near the graft in the dental sockets were not formed from the perichondrium; the rate of the alveolar bone healing was retarded, especially in animals that received allografts; with respect to the alveolar socket healing process, there is no advantage in the use of cartilage grafts.     

An evaluation of new attachment formation using a microfibrillar collagen barrier

The objective of this study was to evaluate the effectiveness of microfibrillar collagen as a barrier to prevent epithelial migration and allow for guided tissue regeneration. Fourteen study teeth were selected. Mucoperiosteal flaps were elevated and roots were debrided and planed. Avitene was placed over teeth and alveolar bone. Flaps were then sutured over it. At control sites no Avitene was placed. At 90 days, block sections were obtained and processed for histologic and histometric evaluation. Results revealed that all specimens had a long junctional epithelial attachment. New attachment was present within the area of the root notch at the original level of the alveolar bone, and there was no significant difference in mean connective tissue attachment between the control and experimental specimens (P = 0.614). Avitene did not form an effective barrier to epithelial migration nor did it allow for guided tissue regeneration and significant new attachment formation in humans.     

Application of propolis to dental sockets and skin wounds

The purpose of this study was to examine histologically the effects of propolis topical application to dental sockets and skin wounds. After topical application of either a 10% hydro-alcoholic solution of propolis or 10% hydro-alcoholic solution alone, cutaneous wound healing and the socket wound after tooth extraction were examined. The rats were sacrificed at 3, 6, 9, 15 and 21 days after the operation. The specimens were subjected to routine laboratory studies after staining with hematoxylin and eosin. It was concluded that topical application of propolis hydro-alcoholic solution accelerated epithelial repair after tooth extraction but had no effect on socket wound healing.     

Histologic evaluation of human alveolar sockets treated with an artificial bone substitute material

This study involved a histologic, enzyme histologic, immunohistologic, and three-dimensional microstructure evaluating the extent of osteogenesis and repair in the human alveolar extraction socket achievable with an artificial bone substitute. After tooth extraction in 7 patients, extraction sockets were filled with Mastergraft (15% hydroxyapatite, 85% β-tricalcium phosphate complex). Radiomicrographs and histologic examinations were performed on samples obtained during dental implant placement procedure. On micro-computed tomography, new bone was observed in all collected samples, and osteogenesis was observed to have taken place around the artificial bone substitute. Histologically, active osteogenesis was found throughout the region observed. Addition of new bone around the Mastergraft was observed, and osteoblast-like cells were present. Cells that had partially invaded the artificial bone included tartrate-resistant acid phosphate-positive and CD34-positive cells. These findings indicate that the Mastergraft artificial bone induced osteogenesis in the jawbone and seemed effective for repairing bone defects.     

The turnover of collagen in the dental pulp of rat incisors.

The turnover of collagen in the dental pulp was studied using H3-proline and microchemical techniques. The incorporation of label into the whole tissue was very high, with most of the label being incorporated into the noncollagenous substances. The rate of disappearance of label from collagen approximated the disappearance of label from noncollagenous components, suggesting that the whole pulp was undergoing rapid remodeling. There seems to be more than one metabolic pool of collagen.     

An electron microscopic study of collagen formation in the dental pulp of the human premolar and rat incisor.

Collagen secretion and maturation were investigated at the ultrastructural level. Pulp tissue from the continuously growing incisor of the rat provided excellent material for studying the secretory aspects of the tropocollagen. More mature human pulp material proved valuable in viewing the collagen fibril. A networklike arrangement of fibroblasts and fibrocytes was noted. Various types of cell junction were found in all specimens. The finding of a nexus junction was particularly interesting. It is hypothesized that connected cell systems rather than single cells might be the functional units involved in collagen formation.     

Histologic study of the attachment of muscles to the rat mandible

The relationship of muscle to periosteum, tendon and ultimately to bone was studied in histological sections of rat mandibles aged 19 days in utero to 56 days postnatal. The following stains were employed: Van Gieson, Masson trichrome, Couciero and Friere, Gomori, orcinol-new fuchsin and Fullmer. Three modes of muscle attachment to the growing rat mandible were described according to the arrangement of collagen and reticular fibres at the interface between the bone and muscles. The morphological characteristics of the three modes persisted even in 56-day-old rats. The structure of the muscle-bone interface suggested a single mechanism of adaptation of muscles to bone during growth. With maturation, the size, number and variety of cells decreased and the size and thickness of collagen fibres increased in the muscle attachments. Each muscle was attached to the mandible by one or more types of attachment defined in this study. A schematic map of the distribution of the different attachment modes associated with muscles of the rat mandible was constructed. Distinction between these modes of attachment may be important in relating the form of a bone to its function.     

Histologic demonstration of bacteria subjacent to dental restorations

abstract – Sections of demineralized teeth which had received experimentally inserted restorations using a variety of materials have been stained according to the Brown and Brenn technique. Conventional cavity preparations had been made in intact areas and the cavities were dried gently without additional treatment prior to restoration. Different restorative materials were used and the teeth were extracted after 3–117 days' observation. No bacteria could be demonstrated at the dentin/filling interface or in the dentin if zinc oxide/eugenol, Ca(OH)2 mixed with water or corticosteroid/antibiotic preparations were employed as base or lining materials. A few bacteria were found subjacent to two of seven unlined amalgam fillings and subjacent to three silicate restorations which had been lined with a polymeric material.     

纳米晶羟基磷灰石复合胶原材料在拔牙创修复中的作用

目的:探讨纳米晶羟基磷灰石复合胶原材料(nHAC)在拔牙创修复中的作用。方法:拔除12只成年狗两侧下颌第二及第三切牙,并去除牙槽间隔,一侧随即植入nHAC,对侧植入致密多晶羟基磷灰石微粒人工骨(HA)作为对照。于植入后4、8、12周分别取材,采用99mTc MDP核素骨显像、组织学观察、图像分析等方法比较两种植入材料在牙槽窝中的骨修复能力。结果:nHAC植入牙槽骨后,材料被逐渐降解吸收,新骨不断生成,12周后植入材料几乎完全被成熟的骨组织取代;图像分析结果显示不同时间nHAC组新骨形成的比值显著高于HA组(P<0.01);4、8、12周nHAC组浓聚程度均高于HA组。结论:nHAC在修复拔牙创缺损时比HA效果更好,是一种较为理想的骨替代材料。     

Immediate placement of dental implants into debrided infected dentoalveolar sockets.

PURPOSE: To describe a protocol for the immediate placement of endosseous implants into debrided infected dentoalveolar sockets. PATIENTS AND METHODS: A total of 30 implants were immediately placed into debrided infected sites in 20 patients. The pathology at the receptacle dentoalveolar sockets varied, and included subacute periodontal infection, perio-endo infection, chronic periodontal infection, chronic periapical lesion, and a periodontal cyst. The immediate placement protocol emphasized the meticulous debridement of the infected tissues in combination with peripheral ostectomy of the alveoli. Guided bone regeneration was accomplished to support bony healing of alveolar defects surrounding the implantation site. Pre- and postsurgical antibiotic therapy was administered. RESULTS: All implants but 1 were osseointegrated and functional when followed up after 12 to 72 months. One implant was mobile after its immediate restoration and was removed. Complications were related to the use of guided bone regeneration. Deficiency of the attached gingiva was noted in 1 case. The treatment approach is illustrated in 2 anterior maxilla cases with 3-year follow-up. CONCLUSIONS: Successful immediate implantation in debrided infected alveoli depends on the complete removal of all contaminated tissue and the controlled regeneration of the alveolar defect. With this proposed clinical approach, experienced clinicians may consider immediate implants as a viable treatment option in patients presenting with dentoalveolar infections.     

338枚即刻种植义齿的临床疗效观察

目的:探讨即刻种植义齿修复牙缺失外科植入和修复方法;初期:(≥6月)和远期(≥36个月)疗效;评价其相关影响因素.方法:291例拔牙患者在拔除牙根后立即在牙槽窝内植入种植体338枚(HBIC,CDIC,CAMLOG,ITI,DIO,OSSTEM,XIVE),3-6月后延期修复,观察6-60个月.结果:338枚种植体随访300枚,6-60个月存留率95.67%.结论:即刻种植义齿修复具有自身优点和适应症,长期效果与延期种植效果无显著性差异,是可行、简便的种植叉齿修复方式之一.