Clinical efficacy of the graft free slit-window sinus floor elevation procedure: A 2-year randomized controlled clinical trial.

OBJECTIVE: Slit-window technique is a lateral approach sinus floor elevation (SFE) procedure that utilizes a rigid resorbable membrane in conjunction with stabilizing bony slits to tent the Schneiderian membrane without addition of grafting materials. The aim of this randomized clinical trial was to compare clinical and radiographic outcomes of the Slit-window SFE with those of SFE with bone grafting. MATERIAL AND METHODS: Thirty-three patients with 38 edentulous sites were included. Edentulous sites were randomly allocated to the Slit-window SFE or SFE with bone grafting. Simultaneous with SFE, each site received two dental implants. Implant stability quotient (ISQ) values were recorded at baseline and monthly visits for 8 months. The bone coverage and bone height gain at implant sites were recorded on cone beam computed tomography (CBCT) scans 6 and 24 months postoperatively. RESULTS: There were no significant differences in the mean ISQ values between the groups at any time point (p > 0.05). All implants in both groups were found to have complete bone coverage. Significant increases in the bone height were found 6 and 24 months postoperatively in both groups (p < 0.001). CONCLUSIONS: Within limitations of the present study, it can be concluded that the Slit-window SFE technique without the need for bone grafting resulted in sufficient bone height gain around implants placed simultaneous with the SFE procedures. The bone height around these implants was stable during the 2-year follow-up period. The treatment outcomes for these implants were comparable to those placed simultaneous with lateral approach SFE in conjunction with bone grafting.

Pilot study: Raman spectroscopy in differentiating premalignant and malignant oral lesions from normal mucosa and benign lesions in humans.

BACKGROUND: Current practice for differentiating tissue lesions are based on histopathological criteria. This process is subject to error. The purpose of this study was to test whether an alternative, tissue-based molecular signatures Raman spectra could be used to differentiate premalignant and malignant lesions from normal mucosa or benign lesions. METHODS: Eighteen treatment naive subjects with histologically diagnosed oral disease were studied by comparing the Raman spectra of lesions with contralateral healthy sites. Principle component and multivariate analysis were used to predict which of the tissue groups the average spectrum of each lesion or normal tissue belonged. RESULTS: The average spectra were clearly different between premalignant and malignant lesions and those derived from normal, benign tissues. Premalignant and malignant lesions could be predicted with 100% sensitivity and 77% specificity. CONCLUSION: Raman spectroscopy (RS) offers the potential to provide point of care diagnosis of oral disease using a noninvasive, convenient, and relatively inexpensive technology.

Growth factor-mediated vertical mandibular ridge augmentation: a case report.

Posterior vertical alveolar ridge deficiencies are challenging defects to treat predictably and often require autogenous bone-harvesting procedures. Traditional treatment modalities, eg, guided bone regeneration, distraction osteogenesis, and autogenous grafts, present with a number of potential complications and limited success when used to restore vertical ridge height. Recent advances in recombinant growth factor technology may provide viable, alternative therapies for the treatment of significant alveolar ridge deficiencies. This proof-of-principle case report examines the utility and effectiveness of using a composite graft of freeze-dried bone allograft and recombinant human platelet-derived growth factor BB in conjunction with an overlying titanium mesh to regenerate well-vascularized bone in a significant posterior mandibular ridge defect prior to implant placement. The important role of the overlying periosteum as a possible key source of osteogenic cells during growth factor-enhanced regenerative procedures is emphasized.

Effect of misfit of cement-retained implant single crowns on crestal bone changes.

The purpose of this clinical study was to compare peri-implant crestal bone levels between misfitting (overhanging/open margin) cement-retained implant single crowns (SCs) vs accurately fitted implant SCs. Seventeen subjects were divided into two groups: test group (misfitting crowns, n = 10) and control group (accurately fitted crowns, n = 7). Crestal bone level changes were assessed using digital software. The average differences in mean bone loss within and between the two groups were statistically significant. Cement-retained implant SCs with marginal misfit resulted in more crestal bone loss than accurately fitted crowns after a mean of 3 years in function.

Supramandibular canal portion superior to the fossa of the submaxillary gland: a tomographic evaluation of the cross-sectional dimension in the molar region.

PURPOSE: Within the fossa of the submaxillary gland (FSG), there is a portion superior to the mandibular canal (SMCP) that can affect implant placement. Our study evaluated this specific portion's prevalence and its average dimensional difference between the first and the second molar regions in a dental implant population. MATERIALS AND METHODS: From 112 patients' mandibular cone beam computerized tomography scans, the SMCPs of the FSG's horizontal and vertical dimensions in the first and second molar positions on both sides were digitally measured. RESULTS: The SMCP of the FSG is larger in the second molar region than in the first molar region in >90% of cases. Average differences were 2.3 mm horizontally and 2.7 mm vertically. Gender difference and intraindividual's left/right variation were both clinically less significant in magnitude than the difference between the molar regions. Taking the 2-mm safety margin above the mandibular canal into consideration, the SMCP of the FSG remained high in prevalence. CONCLUSIONS: The SMCP of the FSG may complicate implant placement more in the second molar region than in the first. Implant planning in the posterior mandibular molar regions should include a SMCP of the FSG evaluation using computer tomography especially in the second molar region.

Laser raman spectroscopy as a potential chair-side microbiological diagnostic device.

INTRODUCTION: Culture-dependent and -independent techniques are time-consuming processes requiring highly trained personnel to identify microorganisms contained within a sample. Rapid chair-side identification of microorganisms could reduce the lag time between patient presentation and ideal treatment. As a first step toward this goal, this study aims to determine if laser Raman spectroscopy (LRS) can discern uniqueness among 10 different species of bacteria contained within a medium in unprocessed and processed samples. METHODS: Ten bacterial species were individually grown on blood agar plates for 3 days. Checkerboard DNA-DNA hybridization was used for species verification. For the unprocessed samples, a 1.0-cm diameter agar sample, with undisturbed bacterial growth, was transferred for each species to a barium fluoride crystal (BaF(2)) slide and laser scanned for a total of 15 seconds per sample. For the processed samples, bacterial cells were harvested, washed, and resuspended in phosphate-buffered saline buffer at 10(9) cells/mL concentration. Each suspension was laser scanned for 15 seconds on a BaF(2) slide. Select regions of Raman spectra for each species/agar and species/suspension combination were processed using a two-sided t test. RESULTS: For the 10 bacterial species, 45 bacteria pair combinations were tested for each group. In both groups, LRS was capable of statistically distinguishing among a majority of bacterial pairings based on RS signature differences of means. CONCLUSIONS: Results show each bacterial species generated restricted ranges of unique spectral signatures that were not masked by their containing medium. Chair-side LRS is a promising technique that differentiates among oral bacterial species with a high degree of specificity.

Factors associated with dental implant survival: a 4-year retrospective analysis.

BACKGROUND: Dental implants are a predictable treatment option for replacing missing teeth and have strong survival and success outcomes. However, previous research showed a wide array of potential risk factors that may have contributed to dental implant failures. The objectives of this study are to study if implant survival rates were affected by known risk factors and risk indicators that may have contributed to implant failures. The secondary outcome measures were whether the level of expertise of the periodontal residents affected success rates and how the rate of implant success at the Harvard School of Dental Medicine (HSDM) compared to published standards. METHODS: A retrospective chart review of patients at the HSDM who had one of two types of rough-surface implants (group A or B) placed by periodontology residents from 2003 to 2006 was performed. Demographic, health, and implant data were collected and analyzed by multimodel analyses to determine failure rates and any factors that may have increased the likelihood of an implant failure. RESULTS: The study cohort included 341 dental implants. The odds ratio for an implant failure was most clearly elevated for diabetes (2.59 implant surface group B (7.84), and male groups (4.01). There was no significant difference regarding the resident experience. The success rate for HSDM periodontology residents was 96.48% during the 4-year study period. CONCLUSIONS: This study demonstrates that implant success rates at HSDM fell within accepted published standards, confirmed previously identified risk factors for a failure, and potentially suggested that other acknowledged risk factors could be controlled for. Furthermore, the level of experience of the periodontology resident did not have an impact on survival outcomes.

Histologic evidence of a connective tissue attachment to laser microgrooved abutments: a canine study.

Previous research has demonstrated the effectiveness of laser-ablated microgrooves placed on implant collars to support direct connective tissue attachments to altered implant surfaces. Such a direct connective tissue attachment serves as a physiologic barrier to the apical migration of the junctional epithelium and prevents crestal bone resorption. The current prospective preclinical trial sought to evaluate bone and soft tissue healing patterns when laser-ablated microgrooves were placed on the abutment. A canine model was selected for comparison to previous investigations that examined the negative bone and soft tissue sequelae of the implant-abutment microgap. The results demonstrate significant improvement in peri-implant hard and soft tissue healing compared to traditional machined abutment surfaces.

Parameters defining the potential applicability of Raman spectroscopy as a diagnostic tool for oral disease.

Raman spectroscopy can provide information about the molecular composition of tissues, with potential to be applied as a diagnostic tool in lieu of histopathology. Our objectives are to determine if laser Raman spectra (RS) can be acquired reliably from the oral mucosa of patients, and to determine if the RS signature of normal oral mucosa is reproducible among anatomic oral sites and among subjects of different races and gender. 25 Caucasian and 26 Asian subjects are studied using RS with a signal acquisition time of 1 s at seven specified sites within the mouth. Multivariate analysis is used to determine the variability between tissue types and between races and gender. Unique spectra are defined for various sites in the mouth and are likely related to the degree of keratinization. However, spectral concordance by site is not greatly influenced by subject ethnicity or gender. We demonstrate, for the first time, the potential in-vivo application of RS for oral mucosal disease and demonstrate its specificity for particular mucosal types in the mouth. RS offers the potential to provide a diagnosis of disease using a noninvasive, convenient, sensitive technology that provides immediate results.