Digital subtraction radiographic analysis of the combination of bioabsorbable membrane and bovine morphogenetic protein pool in human periodontal infrabony defects

Enhanced effectiveness of silver diamine fluoride application with light curing on natural dentin carious lesions: an in vitro study

This study aimed to compare the mean mineral density difference (mMDD) and surface morphology of 10- and 60-s silver diamine fluoride (SDF)-applied dentin carious lesions and to study the effect of an additional 20-s light curing (LC) on SDF-treated teeth. Forty primary molar blocks with natural dentin carious lesions were measured for baseline lesion depth and mineral density using Image-Pro Plus software. The samples were randomly distributed into 4 groups; 38% SDF applied for 1) 10-s (10SDF), 2) 60-s (60SDF), 3) 10-s + LC (10SDF + LC), 4) 60-s + LC (60SDF + LC) and an additional control group to assess the outcome of pH-cycling only. Then all the groups underwent a 7-d bacterial pH-cycling. The dentin carious lesions' mMDD was determined by digital subtraction radiographic analysis. The surface morphology and elemental profile were assessed by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The mMDD of the dentin lesions was analyzed using two-way ANOVA, generalized linear models analysis. Light curing was the only factor that affected the mMDD (p = 0.007). The mMDD in the 10SDF + LC and 60SDF + LC groups were significantly higher than those without light curing (p = 0.041 and 0.041, respectively). The 60SDF + LC group demonstrated a significantly higher mMDD than the 10SDF group (p = 0.010), while that in the 10SDF + LC group was similar to the 60SDF group (p = 1.00). Scanning electron microscopy revealed denser mineral content layers, which were likely silver and chloride, in the 10SDF + LC and 60SDF + LC groups than in the 10SDF and 60SDF groups, respectively. In conclusion, shortened application time with light curing enhanced SDF remineralization similarly to the conventional method.

Experimental and clinical studies on regenerative periodontal therapy

The recognition of a periodontal therapy as a regenerative procedure requires the demonstration of new cementum, periodontal ligament, and bone coronal to the base of the defect. A diversity of regenerative strategies has been evaluated, including root surface conditioning, bone grafts and bone substitute materials, guided tissue regeneration, enamel matrix proteins, growth/differentiation factors, combined therapies and, more recently, tissue-engineering approaches. The aim of this chapter of Periodontology 2000 is to review the research carried out in Latin America in the field of periodontal regeneration, focusing mainly on studies using preclinical models (animal models) and randomized controlled clinical trials. This review may help clinicians and researchers to evaluate the current status of the therapies available and to discuss the challenges that must be faced in order to achieve predictable periodontal regeneration in clinical practice.

Treatment of intrabony defects with modified perforated membranes in aggressive periodontitis: subtraction radiography outcomes, prognostic variables, and patient morbidity

Objectives

The main objectives of this study were (1) to evaluate bone/graft density alterations by digital subtraction radiography; (2) to determine factors associated with favorable clinical and radiographic outcomes, and (3) to report on patient morbidity after guided tissue regeneration (GTR) in aggressive periodontitis (AgP) patients.

Materials and methods

Adapting a split-mouth design, 30 comparative intrabony defects in 15 patients were randomly treated with xenogenic graft plus modified perforated membranes (MPM, tests) or xenogenic graft plus standard collagen membranes (CM, controls). The time period of observation was 12 months.

Results

There were significant improvements in clinical and radiographic parameters within each group, without intergroup differences. However, higher PPD reduction for three-wall defects was noted in MPM sites (5.22 versus 3.62 mm; p = 0.033). Moreover, a significant gain in bone/graft density of 4.9% from 6 to 12 months post-operatively was observed in test sites. Multivariate analysis demonstrated that morphology of intrabony defects was a predictor of CAL gain (p = 0.06), while independent prognostic variables effecting changes in bone/graft density were radiographic defect depth (p = 0.025) and radiographic angle (p = 0.033). The majority of patients reported some discomfort, pain, and edema with mild intensity without any significant differences between treatment modalities.

Conclusions

This study demonstrated enhanced bone/graft density gain after GTR with MPM, which may indicate greater area of new bone formation. Independent variables effecting treatment outcomes were intrabony defect morphology, radiographic defect depth, and radiographic angle.

Clinical relevance

This study supports the regenerative treatment of intrabony defects in AgP patients and identifies some variables with prognostic value.

Non-cross-linked collagen type I/III materials enhance cell proliferation: in vitro and in vivo evidence

Objective

To analyze Mucograft^®(MG), a recently introduced collagen matrix, in vitro and in vivo, and compare it with BioGide^®(BG), a well-established collagen membrane, as control.

Material and Methods

A detailed analysis of the materials surface and ultra-structure was performed. Cellular growth patterns and proliferation rates of human fibroblasts on MG and BG were analyzed in vitro. In addition, the early tissue reaction of CD-1 mouse to these materials was analyzed by means of histological and histomorphometrical analysis.

Results

MG showed a three-fold higher thickness both in dry and wet conditions, when compared to BG. The spongy surface of BG significantly differed from that of MG. Cells showed a characteristic proliferation pattern on the different materials in vitro. Fibroblasts tended to proliferate on the compact layers of both collagens, with the highest values on the compact side of BG. In vivo, at day three both materials demonstrated good tissue integration, with a mononuclear cell sheet of fibroblasts on all surfaces, however, without penetrating into the materials.

Conclusions

The findings of this study showed that MG and BG facilitate cell proliferation on both of their surfaces in vitro. In vivo, these two materials induce a comparable early tissue reaction, while serving as cell occlusive barriers.

Tissue engineering in dentistry

OBJECTIVES

of this review is to inform practitioners with the most updated information on tissue engineering and its potential applications in dentistry.

DATA

The authors used "PUBMED" to find relevant literature written in English and published from the beginning of tissue engineering until today. A combination of keywords was used as the search terms e.g., "tissue engineering", "approaches", "strategies" "dentistry", "dental stem cells", "dentino-pulp complex", "guided tissue regeneration", "whole tooth", "TMJ", "condyle", "salivary glands", and "oral mucosa".

SOURCES

Abstracts and full text articles were used to identify causes of craniofacial tissue loss, different approaches for craniofacial reconstructions, how the tissue engineering emerges, different strategies of tissue engineering, biomaterials employed for this purpose, the major attempts to engineer different dental structures, finally challenges and future of tissue engineering in dentistry.

STUDY SELECTION

Only those articles that dealt with the tissue engineering in dentistry were selected.

CONCLUSIONS

There have been a recent surge in guided tissue engineering methods to manage periodontal diseases beyond the traditional approaches. However, the predictable reconstruction of the innate organisation and function of whole teeth as well as their periodontal structures remains challenging. Despite some limited progress and minor successes, there remain distinct and important challenges in the development of reproducible and clinically safe approaches for oral tissue repair and regeneration. Clearly, there is a convincing body of evidence which confirms the need for this type of treatment, and public health data worldwide indicates a more than adequate patient resource. The future of these therapies involving more biological approaches and the use of dental tissue stem cells is promising and advancing. Also there may be a significant interest of their application and wider potential to treat disorders beyond the craniofacial region.

CLINICAL SIGNIFICANCE

Considering the interests of the patients who could possibly be helped by applying stem cell-based therapies should be carefully assessed against current ethical concerns regarding the moral status of the early embryo.