Addition of Synthetic Biomaterials to Deproteinized Bovine Bone Mineral (DBBM) for Bone Augmentation-A Preclinical In Vivo Study.

(1) Aim: To investigate the effect of synthetic bone substitutes, α-tricalcium phosphate (α-TCP) or bi-layered biphasic calcium-phosphate (BBCP) combined with deproteinized bovine bone mineral (DBBM), on bone formation. (2) Methods: Thirty critical size defects were randomly treated with the following five different treatment modalities: (1) negative control (NC, empty), (2) DBBM, (3) α-TCP + DBBM (1:1), (4) BBCP 3%HA/97%α-TCP + DBBM (1:1), and (5) BBCP 6%HA/94%α-TCP + DBBM (1:1). The samples, at four weeks post-surgery, were investigated by micro-CT and histological analysis. (3) Results: A similar level of new bone formation was demonstrated in the DBBM with α-TCP bone substitute groups when compared to the negative control by histomorphometry. DBBM alone showed significantly lower new bone area than the negative control (p = 0.0252). In contrast to DBBM, the micro-CT analysis revealed resorption of the α-TCP + DBBM, BBCP 3%HA/97%α-TCP + DBBM and BBCP 6%HA/94%α-TCP + DBBM, as evidenced by a decrease of material density (p = 0.0083, p = 0.0050 and p = 0.0191, respectively), without changing their volume. (4) Conclusions: New bone formation was evident in all defects augmented with biomaterials, proving the osteoconductive properties of the tested material combinations. There was little impact of the HA coating degree on α-TCP in bone augmentation potential and material resorption for four weeks when mixed with DBBM.

Long-term clinical outcomes of periodontal regeneration with enamel matrix derivative: A retrospective cohort study with a mean follow-up of 10 years.

BACKGROUND: Despite the large body of evidence on the efficacy of enamel matrix derivative (EMD) in the treatment of periodontal intrabony defects, few studies reported long-term data (≥10-year). METHODS: Periodontal patients treated with regenerative surgery with EMD between 1999 and 2012 were invited to participate in a clinical examination. The following clinical parameters were recorded and compared at baseline (T0), 6 months after surgery (T1) and after at least 8 years of follow-up (T2): probing depth (PD), gingival recession (GR), clinical attachment level (CAL), plaque and bleeding scores. The primary outcome variable was CAL change. RESULTS: Forty-one patients with 75 treated teeth were available for analysis. Out of these, 68 (tooth survival rate: 90.7%) reached the latest follow-up with a mean observation period of 10.3 years (range: 8.0 to 21.3). The most frequent reason for tooth loss was recurrence of periodontal disease. Tooth survival curves showed a statistically significant difference between smokers and non-smokers (P = 0.028). Mean CAL changed from 8.43 ± 1.86 (T0) to 6.47 ± 1.70 (T1) (P < 0.001) and to 5.91 ± 1.83 (T2) (P < 0.001). At T1, a CAL gain of ≥3 mm was measured in 35% of the defects whereas at T2 it was detected in 51% of cases. CONCLUSIONS: Within their limitations, the present results have shown that in intrabony defects, the clinical improvements obtained following regenerative surgery with EMD can be maintained on a mean period of 10 years. Smoking status and maxillary molars were correlated with an increased risk for tooth and CAL loss, respectively.

Impact of Cross-Linking of Collagen Matrices on Tissue Regeneration in a Rabbit Calvarial Bone Defect.

The cross-linking of collagen matrices (Cl_CM) may provide volume-stable enhanced defect regeneration when compared to non-cross-linked matrices (Ncl_CM). The aim of the present study was to investigate the bone forming potential of collagen matrices (CMs) and the effects of cross-linking CMs in a rabbit calvaria defect model. (1) Empty controls (n = 6), (2) Ncl_CM (n = 8), and (3) Cl_CM (n = 8) were selected to be observed for the healing in 10 mm critical-sized calvarial bone defects. The potential for the bone as well as the connective tissue formation were evaluated by micro-CT and histomorphometry at three months post-surgery. There were no statistically significant differences in terms of new bone volume in the defects between the groups. However, the Cl_CM induced significantly greater fibrous tissue regeneration (5.29 ± 1.57 mm2) when compared to the controls (3.51 ± 0.93 mm2) by histomorphometry. The remnants of collagen fibers with immune cells, including macrophages and giant cells, were occasionally observed in the Cl_CM group but not in the Ncl_CM group. In conclusion, the cross-linking of collagen did not influence the potential for bone formation. Nevertheless, Cl_CM might be advantageous for the maintenance of fibrous tissue volume without disturbing bone formation in the defects.

Implant Disease Risk Assessment IDRA-a tool for preventing peri-implant disease.

OBJECTIVE: This treatment concept paper introduces a risk assessment tool, the Implant Disease Risk Assessment, (IDRA) which estimates the risk for a patient to develop peri-implantitis. MATERIALS AND METHODS: The functional risk assessment diagram was constructed incorporating eight parameters, each with documented evidence for an association with peri-implantitis. RESULTS: The eight vectors of the diagram include (1) assessment of a history of periodontitis (2) percentage of sites with bleeding on probing (BOP) (3) number of teeth/implants with probing depths (PD) ≥5 mm (4) the ratio of periodontal bone loss (evaluated from a radiograph) divided by the patient's age (5) periodontitis susceptibility as described by the staging and grading categories from the 2017 World Workshop on the Classification of Periodontal and Peri-implant Diseases (Journal of Periodontology, 89 Suppl 1, S159-S172, 2018) (6) the frequency/compliance with supportive periodontal therapy (7) the distance in mm from the restorative margin of the implant-supported prosthesis to the marginal bone crest and (8) prosthesis-related factors including cleanability and fit of the implant-supported prosthesis. CONCLUSION: The combination of these factors in a risk assessment tool, IDRA, may be useful in identifying individuals at risk for development of peri-implantitis.

The effect of systemic antibiotics on clinical and patient-reported outcome measures of oral implant therapy with simultaneous guided bone regeneration.

OBJECTIVES: The aim of the present superiority study was to determine the effect of systemic antibiotics primarily on patient-reported outcome measures (PROMs) and post-surgical complications in patients undergoing oral implant therapy with simultaneous guided bone regeneration (GBR). MATERIALS AND METHODS: A total of 236 medically and periodontally healthy patients received oral implants with simultaneous GBR at seven centres. Pre-operative antibiotics of 2 g amoxicillin were prescribed to the test group 1 hr prior to surgery and 500 mg thrice daily on days 1-3 after surgery. The control group was given a placebo. Group allocation was performed randomly. Primary outcome variables were PROMs recorded as visual analogue scale scores assessed on days 1-7 and 14 on pain, swelling, haematoma and bleeding. Post-operative complications as secondary outcome variables were examined at 1, 2, 4 and 12 weeks from surgery. Chi-square tests and repeated measures of analysis of variance (ANOVA) were performed for statistical evaluation. RESULTS: No statistically significant differences (p > .05) between the two groups were detected for the evaluated PROMs. The same was noted with respect to post-surgical complications. Four implants were lost-three in the test group and one in the control group. CONCLUSION: In this trial, systemic antibiotics did not provide additional benefits to PROMs, nor the prevention of post-surgical complications in medically and periodontally healthy patients undergoing oral implant therapy with simultaneous GBR. However, further studies with larger sample sizes are still required to support the clinical outcomes of this study.

Tomographic evaluation of the influence of the placement of a collagen membrane subjacent to the sinus mucosa during maxillary sinus floor augmentation: a randomized clinical trial.

AIM: To study the influence of a collagen membrane placed subjacent to the sinus mucosa on the dimensional changes of augmented maxillary sinus floor. METHODS: Twenty patients were recruited in the study and randomly assigned to two groups. After the elevation of the maxillary sinus mucosa, a collagen membrane with standardized dimensions was placed at the test sites subjacent to the sinus mucosa and the elevated space was filled with a xenograft, both at test and control sites. A collagen membrane was then used to cover the antrostomy at both sites, and sutures were applied to close the wounds. Cone beam computed tomographies (CBCTs) were taken for all patients before surgery (T0), after 1 week from sinus floor augmentation (T1), and after 9 months of healing (T2). Dimensional changes over time of soft and hard tissues were evaluated on the CBCTs. RESULTS: After 1 week of healing, the sinus floor was elevated by 10.0 ± 2.8 mm and 10.6 ± 2.5 mm at the no-membrane and membrane groups, respectively. After 9 months of healing, a similar reduction of the height was observed in both groups, providing a total vertical augmentation of 8.6 ± 2.8 mm at the no-membrane sites and 9.1 ± 3.1 mm at the membrane sites. After 9 months of healing, the hard tissues subjacent to the sinus mucosa appeared to be partially corticalized in three patients in the no-membrane group and in six patients in the membrane group. CONCLUSIONS: The use of collagen membranes subjacent to the sinus mucosa did not influence the dimensional variations of the augmented regions and the clinical outcomes after 9 months of healing also in absence of perforations.

Nonsurgical therapy for teeth and implants-When and why?

As periodontal and peri-implant diseases represent opportunistic infections, antiinfective therapy is the method of choice. Correctly performed, the treatment outcomes will include resolution of the inflammation concomitant with shrinkage of the tissues, reflected in reduced probing depths. Depending on the patient data obtained after initial antiinfective therapy, further - mostly surgical - treatment may be rendered to reach the goals of a healthy periodontium and peri-implant tissues. Patient compliance is as important as operator skills for optimal treatment outcomes. Regenerative therapy may be applied in compliant patients and for appropriate defects. This article depicts the historical development of periodontal therapy during the 20th century and addresses the various outcome parameters to be used in daily decision making. Obviously, nonsurgical therapy has gained clinical relevance, resulting in highly satisfactory treatment outcomes in many cases. The critical probing depth above which positive attachment gain is registered varies from one treatment modality to another. It is a concept that helps facilitate decision making for additional therapeutic measures after initial therapy. Treatment of peri-implant mucositis prevents development of peri-implantitis. Hence, nonsurgical treatment of mucositis is frequently performed during the continuous monitoring of oral implants. This chapter of Periodontology 2000 presents evidence for the prevention and therapy of peri-implant diseases.

How do visual-spatial and psychomotor abilities influence clinical performance in periodontal plastic surgery?

AIM: We want to evaluate the relationship of self-assessed experience and proficiency, manual dexterity and visual-spatial ability with surgical performance. MATERIAL AND METHODS: A total of 26 professionals were included in the study which consisted of four parts: (a) self-assessment by a questionnaire regarding proficiency and experience, (b) evaluation of visual-spatial ability, (c) testing of manual dexterity assessed by validated psychomotor tests and (d) evaluation of surgical performance by Objective Structured Assessment of Technical Skills (OSATS). RESULTS: Self-assessed proficiency and experience levels did not correlate with objectively evaluated surgical performances (OSATS). However, low-level visual-spatial ability tests strongly correlated with OSATS while intermediate- and high-level tests did not. No correlation was found between psychomotor ability and clinical performance. CONCLUSIONS: Self-assessed proficiency is not a good predictor for surgical performance as experts tend to be overconfident. To evaluate and predict surgical performance, visual-spatial ability tests seem to be more appropriate than measuring manual dexterity which failed to correlate with the surgical outcome.

Influence of the height of the antrostomy in sinus floor elevation assessed by cone beam computed tomography- a randomized clinical trial.

PURPOSE: To evaluate the influence of the height of the antrostomy on dimensional variations of the elevated space after sinus floor elevation. MATERIALS AND METHODS: Twenty-four healthy volunteers planned for sinus floor elevation were included in the study. An antrostomy of either 4 mm (Group A) or 8 mm (Group B) in height was prepared in the lateral wall of the sinus. Cone beam computed tomography (CBCT) scans were taken before surgery (T0) and after 1 week (T1) and 9 months (T2). Dimensional variation analyses were performed. RESULTS: The CBCT scans of 10 patients per group were evaluated. After 1 week (T1), the sinus floor was found elevated in the middle region by 12.0 ± 2.3 mm in Group A, while in Group B, the height was 11.8 ± 2.1 mm. After 9 months (T2), the respective heights were 9.9 ± 2.4 mm and 8.9 ± 2.7 mm, with a reduction of -2.1 ± 2.2 mm in Group A and -3.0 ± 2.6 mm in Group B. The area in a central position was reduced by 25.5% to 34.2%, showing a slightly higher shrinkage in Group B compared with Group A. However, no statistically significant differences were found between the two groups. DISCUSSION: In maxillary sinus floor elevations performed by the lateral approach, the size of the antrostomy did not affect the clinical and radiographic outcomes.

Influence of the position of the antrostomy in sinus floor elevation assessed with cone-beam computed tomography: A randomized clinical trial.

AIM: The aim of the present study was to evaluate dimensional variations of augmented sinus volumes after sinus floor elevation using a lateral approach placing the antrostomy close to the sinus floor or more cranially to it. METHODS: Twenty-four healthy volunteers in need of sinus floor elevation were included in the study. The lateral approach was adopted placing the antrostomy randomly either close to the level of the sinus floor (group A) or approximately 3-4 mm cranially (group B). Cone-beam computed tomography (CBCT) was done before surgery (T0) and after 1 week (T1) and 9 months (T2), and analyses on dimensional variations were performed. RESULTS: CBCT of 10 patients per group were analyzed. At T1, the sinus floor was found to be elevated by 9.8 ± 2.1 mm in group A and 10.9 ± 1.9 mm in group B. At T2, shrinkage of 2.0 ± 1.7 mm in group A and 1.4 ± 2.5 mm in group B was observed. The area was reduced approximately 18-24% between T1 and T2. The sinus mucosa width increased by 4.3-5 mm between T0 and T1, and regained the original dimensions at T2. CONCLUSIONS: The more cranial the antrostomy, the greater the augmentation height after 9 months.

Periodontal health and gingival diseases and conditions on an intact and a reduced periodontium: Consensus report of workgroup 1 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions.

Periodontal health is defined by absence of clinically detectable inflammation. There is a biological level of immune surveillance that is consistent with clinical gingival health and homeostasis. Clinical gingival health may be found in a periodontium that is intact, i.e. without clinical attachment loss or bone loss, and on a reduced periodontium in either a non-periodontitis patient (e.g. in patients with some form of gingival recession or following crown lengthening surgery) or in a patient with a history of periodontitis who is currently periodontally stable. Clinical gingival health can be restored following treatment of gingivitis and periodontitis. However, the treated and stable periodontitis patient with current gingival health remains at increased risk of recurrent periodontitis, and accordingly, must be closely monitored. Two broad categories of gingival diseases include non-dental plaque biofilm-induced gingival diseases and dental plaque-induced gingivitis. Non-dental plaque biofilm-induced gingival diseases include a variety of conditions that are not caused by plaque and usually do not resolve following plaque removal. Such lesions may be manifestations of a systemic condition or may be localized to the oral cavity. Dental plaque-induced gingivitis has a variety of clinical signs and symptoms, and both local predisposing factors and systemic modifying factors can affect its extent, severity, and progression. Dental plaque-induced gingivitis may arise on an intact periodontium or on a reduced periodontium in either a non-periodontitis patient or in a currently stable "periodontitis patient" i.e. successfully treated, in whom clinical inflammation has been eliminated (or substantially reduced). A periodontitis patient with gingival inflammation remains a periodontitis patient (Figure 1), and comprehensive risk assessment and management are imperative to ensure early prevention and/or treatment of recurrent/progressive periodontitis. Precision dental medicine defines a patient-centered approach to care, and therefore, creates differences in the way in which a "case" of gingival health or gingivitis is defined for clinical practice as opposed to epidemiologically in population prevalence surveys. Thus, case definitions of gingival health and gingivitis are presented for both purposes. While gingival health and gingivitis have many clinical features, case definitions are primarily predicated on presence or absence of bleeding on probing. Here we classify gingival health and gingival diseases/conditions, along with a summary table of diagnostic features for defining health and gingivitis in various clinical situations.

Periodontal health and gingival diseases and conditions on an intact and a reduced periodontium: Consensus report of workgroup 1 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions.

Periodontal health is defined by absence of clinically detectable inflammation. There is a biological level of immune surveillance that is consistent with clinical gingival health and homeostasis. Clinical gingival health may be found in a periodontium that is intact, i.e. without clinical attachment loss or bone loss, and on a reduced periodontium in either a non-periodontitis patient (e.g. in patients with some form of gingival recession or following crown lengthening surgery) or in a patient with a history of periodontitis who is currently periodontally stable. Clinical gingival health can be restored following treatment of gingivitis and periodontitis. However, the treated and stable periodontitis patient with current gingival health remains at increased risk of recurrent periodontitis, and accordingly, must be closely monitored. Two broad categories of gingival diseases include non-dental plaque biofilm-induced gingival diseases and dental plaque-induced gingivitis. Non-dental plaque biofilm-induced gingival diseases include a variety of conditions that are not caused by plaque and usually do not resolve following plaque removal. Such lesions may be manifestations of a systemic condition or may be localized to the oral cavity. Dental plaque-induced gingivitis has a variety of clinical signs and symptoms, and both local predisposing factors and systemic modifying factors can affect its extent, severity, and progression. Dental plaque-induced gingivitis may arise on an intact periodontium or on a reduced periodontium in either a non-periodontitis patient or in a currently stable "periodontitis patient" i.e. successfully treated, in whom clinical inflammation has been eliminated (or substantially reduced). A periodontitis patient with gingival inflammation remains a periodontitis patient (Figure 1), and comprehensive risk assessment and management are imperative to ensure early prevention and/or treatment of recurrent/progressive periodontitis. Precision dental medicine defines a patient-centered approach to care, and therefore, creates differences in the way in which a "case" of gingival health or gingivitis is defined for clinical practice as opposed to epidemiologically in population prevalence surveys. Thus, case definitions of gingival health and gingivitis are presented for both purposes. While gingival health and gingivitis have many clinical features, case definitions are primarily predicated on presence or absence of bleeding on probing. Here we classify gingival health and gingival diseases/conditions, along with a summary table of diagnostic features for defining health and gingivitis in various clinical situations.

Supportive peri-implant therapy following anti-infective surgical peri-implantitis treatment: 5-year survival and success.

OBJECTIVES: To evaluate clinical outcomes of supportive peri-implant therapy (SPIT) following surgical treatment of peri-implantitis. MATERIALS AND METHODS: Twenty-four partially dentate patients with 36 dental implants diagnosed with peri-implantitis were treated by an anti-infective surgical protocol followed by regular supportive therapy. SPIT included removal of supra- and submucosal biofilm at the treated implants using titanium or carbon fibre curettes, or ultrasonic devices. In addition, professional prophylaxis (calculus/biofilm removal) at other implants/teeth and oral hygiene reinforcement was provided. Clinical measurements and radiographs were obtained at 1, 3 and 5 years. A successful treatment outcome was defined as implant survival with the absence of peri-implant probing depths (PD) ≥ 5 mm with concomitant bleeding/suppuration and absence of progression of peri-implant bone loss. RESULTS: Twelve months after treatment, there was 100% survival of the treated implants and 79% of patients (19 of 24) had a successful treatment outcome according to the defined success criteria. At 3 years, 75% of the patients (18 of 24) had a successful treatment outcome, two patients (8%) were lost to follow-up (LTF), while 8% lost an implant, and two patients had recurrence of peri-implantitis. Between 3 and 5 years, an additional two patients were LTF, and an additional two patients each lost one implant. Thus, at 5 years 63% of patients (15 of 24) had a successful treatment outcome. Complete resolution of peri-implantitis, defined as absence of bleeding at all sites, was achieved in 42% of implants (N = 15) at 5 years. CONCLUSION: Five years following regular supportive therapy, the peri-implant conditions established following peri-implantitis surgery were maintained in the majority of patients and implants. Some patients had recurrence of peri-implantitis and some lost implants over the 5-year period.

A multicenter randomized, controlled clinical trial comparing the use of displacement cords, an aluminum chloride paste, and a combination of paste and cords for tissue displacement.

STATEMENT OF PROBLEM: Gingival recession after soft tissue displacement for impression making in fixed prosthodontics may pose a problem for treatment success in the esthetic areas of the mouth. Knowledge about the soft tissue reaction of common gingival displacement methods is limited. PURPOSE: The purpose of this clinical randomized controlled trial (RCT) was to evaluate changes in the marginal soft tissue height with 3 different gingival tissue displacement techniques for definitive impression making of natural teeth. MATERIAL AND METHODS: A total of 67 individuals were randomized to 3 groups. In test group 1 (P; n=22), only aluminum chloride paste was used to displace the gingiva. In test group 2 (CP; n=23), a cord was inserted, and aluminum chloride paste was also used. In the control group (C; n=22), 2 cords were used to displace the gingiva (double-cord technique). Clinical measurements of the gingival position were made before treatment began and at 30 ±10 days after prosthesis delivery. Study casts were fabricated at different stages of the treatment, standardized photographs were made, and changes in the buccal gingival position were measured using graphics editing software. In addition, the participants' perception of the clinical procedure and the technicians' evaluation of the die preparation were recorded. One-way ANOVA models were applied to compare the response variables among the groups: (a) the position of the gingival margin (millimeters), (b) mean probing pocket depth (millimeters), (c) gingival thickness (millimeters), (d) amount of keratinized tissue (millimeters), and (e) mean changes in gingival margin height (millimeters). Unpaired t tests were also used to compare the mean values between groups. For comparisons between different categories, chi-square tests were performed (α=.05 for all tests). RESULTS: In the period between impression and delivery, a minor gain in gingival height of 0.058 mm (±0.13 SD) for P and 0.013 mm (±1.19 SD) for CP. However, a minor gingival recession of 0.049 mm (±0.13 SD) was reported for group C. The results for all groups showed that 21% of abutment teeth gained >0.1 mm in gingival height, 58% had stable gingival height (0 ±0.10 mm), 21% showed minor gingival recession (0.1 to 0.5 mm), and no abutment teeth showed moderate or severe gingival recession (>0.5 mm). The incidence of minor gingival recession was 8% in group P, 23% in group CP, and 32% in group C (P=.015). Fifteen participants (24%) experienced some discomfort after the procedure. The differences between the groups were not significant (P>.05). The laboratory technicians found the definitive die preparation significantly more challenging for group P (visual analog scale [VAS], 79) and CP (VAS, 82) than group C (mean VAS, 93; P=.003). CONCLUSIONS: Minor or moderate gingival recession (<1 mm) is more likely to occur when conventional cords are used during impression making. However, the laboratory technicians found the die preparation significantly less challenging when the double-cord technique was used than when impressions were made using the paste displacement technique.

Natural history of periodontitis: Disease progression and tooth loss over 40 years.

OBJECTIVES: To assess long-term attachment and periodontitis-related tooth loss (PTL) in untreated periodontal disease over 40 years. MATERIAL AND METHODS: Data originated from the natural history of periodontitis study in Sri Lankan tea labourers first examined in 1970. In 2010, 75 subjects (15.6%) of the original cohort were re-examined. RESULTS: PTL over 40 years varied between 0 and 28 teeth (mean 13.1). Four subjects presented with no PTL, while 12 were edentulous. Logistic regression revealed attachment loss as a statistically significant covariate for PTL (p < .004). Markov chain analysis showed that smoking and calculus were associated with disease initiation and that calculus, plaque, and gingivitis were associated with loss of attachment and progression to advanced disease. Mean attachment loss <1.81 mm at the age of 30 yielded highest sensitivity and specificity (0.71) to allocate subjects into a cohort with a dentition of at least 20 teeth at 60 years of age. CONCLUSIONS: These results highlight the importance of treating early periodontitis along with smoking cessation, in those under 30 years of age. They further show that calculus removal, plaque control, and the control of gingivitis are essential in preventing disease progression, further loss of attachment and ultimately tooth loss.

Akute Pankreatitis nach nicht chirurgischer Parodontaltherapie in Kombination mit systemischer Antibiotikatherapie.

Non-surgical periodontal therapy is often performed as a combinational approach using supplemental systemic amoxicillin and metronidazole. Better clinical outcomes, less need for periodontal surgery and limited systemic complications are arguments to justify such an approach. However, combination therapy with systemic antibiotic treatment is still a matter of debate due to emerging antibiotic resistance patterns. In this case report, a 61-year-old women suffering from an acute pancreatitis following systemic antibiotic combinational treatment as part of a non-surgical periodontal therapy is described. Following adequate symptomatic treatment during a hospitalization of three days, the patient recovered and periodontal conditions improved significantly thereafter. This case report illustrates a rare, but potentially serious complication when prescribing systemic combinational antibiotics in non-surgical periodontal therapy. Adequate history taking and timely diagnosis of pancreatitis if developing is important to provide relevant treatment and to avoid pancreatitis-associated complications.

Morphometric evaluation of the early stages of healing at cortical and marrow compartments at titanium implants: an experimental study in the dog.

OBJECTIVE: To study the early sequential stages of tissue composition in the cortical and marrow compartments of the alveolar bone crest at implants with a moderately rough surface. MATERIALS AND METHODS: Three month after tooth extraction in 12 Labrador dogs, full-thickness flaps were elevated in the edentulous region of the right side of the mandible and one implant was installed. The flaps were sutured to allow a fully submerged healing. The timing of the installations in the left side of the mandible and of sacrifices were scheduled in such a way to obtained biopsies representing the healing after 5, 10, 20, and 30 days. Ground sections (n = 6 per each healing period) were prepared, and the percentages of osteoid/new bone, old bone, new soft tissues (provisional matrix and primitive marrow), mature bone marrow, vessels, and other tissues (bone debris/particles and clot) were evaluated laterally to the implant surface up to a distance of about 0.4 mm from it. RESULTS: Osteoid/new bone was found after 5 days at percentages of 10.8 ± 4.3% at the marrow and 0.6 ± 0.6% at the cortical compartments. After 30 days, these percentages increased up to 56.4 ± 4.0% and 23.3 ± 6.1%, respectively. Old parent bone was resorbed between 5 and 30 days from 28.7 ± 10.9% to 14.9 ± 3.4% at the marrow (~48% of resorption) and from 81.2 ± 9.4% to 67.6 ± 5.6% at the cortical (~17% of resorption) compartments. All differences were statistically significant. CONCLUSION: Bone apposition to an implant surface followed a significantly different pattern in the compact and the marrow compartments around the implants. While in the compact compartments, bone apposition had to develop through the BMUs following resorption, it developed in very dense layers through an early apposition in the marrow compartments.

Nd:YAG laser radiation (1.064 nm) accelerates differentiation of osteoblasts to osteocytes on smooth and rough titanium surfaces in vitro.

BACKGROUND: A number of studies revealed beneficial effects of low-level laser therapy (LLLT) regarding cell proliferation and differentiation. AIM: To investigate the effect of Nd:YAG (1.064 nm) laser radiation in the proliferation and differentiation potential of MG-63 osteoblast-like cells. Additionally, the effects of the surface configurations were to be evaluated. MATERIAL AND METHODS: MG-63 osteoblast cells were cultured on different surfaces: plastic tissue culture, smooth (polished) titanium-PT and rough titanium-SLA. The effects of both titanium surfaces and low-level laser therapy (LLLT) on cell adhesion were evaluated by the gene expression of molecules involved in cell proliferation and differentiation. In addition, scanning electron microscopy (SEM) and MTT proliferation assays were used to examine cell morphology and proliferation, respectively. RESULTS: Compared to smooth (PT) surfaces, SLA surfaces favoured MG-63 cell differentiation. Following the application of Nd:YAG laser irradiation, cells yielded statistically significantly improved differentiation on both smooth and SLA surfaces compared with non-irradiated surfaces. CONCLUSIONS: The findings of this present study suggest that both surface morphology and Nd:YAG laser irradiation influence the proliferation and differentiation potential of MG-63 cells.

Use of a collagen matrix for recession coverage in patients who received orthodontic therapy: a case series.

AIM: The aim of the present study was to determine the percentage of recession coverage achieved following surgery with a collagen matrix, and patient-reported outcome measures. METHODS: Five healthy adults who had completed orthodontic therapy with a gingival recession defect were recruited. Gingival recession coverage was performed using a two-layer, xenogeneic collagen matrix (Mucograft). During the first 2 weeks, the patients charted their perceptions on bleeding, swelling, pain, and bruising using a visual analog scale (VAS). Post-surgical complications were assessed clinically at 1 week, 2 weeks, and 1 month post-surgery. Recession dimensions were examined at 1, 3, 6, and 12 months. RESULTS: At 1 year, an average of 67% root coverage was achieved. The amount of recession coverage achieved was stable from 3 months. The results were maintained at 1 year. There were no post-surgical complications. All VAS parameters decreased to almost zero by day 14. From day 1, bleeding and pain decreased over time. However, there were peaks on days 2 and 3 for swelling and bruising, respectively, followed by a subsequent decrease. CONCLUSIONS: The use of Mucograft for recession coverage is effective and safe, with low morbidity and no post-surgical complications. Recession coverage achieved at 3 months remained stable in the 1-year follow-up period.

Human Memory B Cells in Healthy Gingiva, Gingivitis, and Periodontitis.

The presence of inflammatory infiltrates with B cells, specifically plasma cells, is the hallmark of periodontitis lesions. The composition of these infiltrates in various stages of homeostasis and disease development is not well documented. Human tissue biopsies from sites with gingival health (n = 29), gingivitis (n = 8), and periodontitis (n = 21) as well as gingival tissue after treated periodontitis (n = 6) were obtained and analyzed for their composition of B cell subsets. Ag specificity, Ig secretion, and expression of receptor activator of NF-κB ligand and granzyme B were performed. Although most of the B cell subsets in healthy gingiva and gingivitis tissues were CD19(+)CD27(+)CD38(-) memory B cells, the major B cell component in periodontitis was CD19(+)CD27(+)CD38(+)CD138(+)HLA-DR(low) plasma cells, not plasmablasts. Plasma cell aggregates were observed at the base of the periodontal pocket and scattered throughout the gingiva, especially apically toward the advancing front of the lesion. High expression of CXCL12, a proliferation-inducing ligand, B cell-activating factor, IL-10, IL-6, and IL-21 molecules involved in local B cell responses was detected in both gingivitis and periodontitis tissues. Periodontitis tissue plasma cells mainly secreted IgG specific to periodontal pathogens and also expressed receptor activator of NF-κB ligand, a bone resorption cytokine. Memory B cells resided in the connective tissue subjacent to the junctional epithelium in healthy gingiva. This suggested a role of memory B cells in maintaining periodontal homeostasis.