Long-term stability (21-30 years) of root coverage outcomes using sub-epithelial connective tissue grafts at single or multiple gingival recessions: A longitudinal case series.

AIM: To evaluate outcomes and predictive factors for the long-term stability of root coverage using a sub-epithelial connective tissue graft. MATERIALS AND METHODS: One-hundred and two healthy subjects (221 gingival recessions, GRs) were treated from 1987 to 1996. Keratinized tissue width (KTW), GR depth (RD), GR width (RW) and GR area (RA) were evaluated at baseline (M0) and at 1 month (M1), 1 year (M2), 11 years (M3), 21 years (M4) and 27 years (M5) after surgery. Primary outcomes consisted of complete root coverage (cRC) and relative dimensional changes in recession depth (measured in mm [c%-RD]), recession width (measured in mm [c%-RW]) and recession area (measured in mm2 [c%-RA]). RESULTS: cRC was 88.7% at 1 year (M2), 59.8% at M3, 44.4% at M4 and 51.9% at M5. Average c%-RD was 95.2% at 1 year, 81.9% at M3, 71.5% at M4 and 81.7% at M5. KTW increased after surgery and over time and was positively correlated with favourable outcomes. Increased baseline RA was associated with less favourable clinical outcomes. CONCLUSIONS: The sub-epithelial connective tissue graft is effective in the treatment of GRs and facilitates long-term stability of clinical outcomes. Wider baseline RA was a strong predictor of unfavourable short- and long-term RC outcomes.

Maxillary Sinus Elevation by Crestal Window: Influence of 3D Sinus Size on Bone Regeneration-A Retrospective Clinical and Histologic Evaluation.

This evaluation correlates maxillary sinus 3D morphology with bone regeneration. In 39 patients with crestal bone ≤ 2 mm, mineralized human bone allografts were used to augment the sinus floor through the crestal window sinus elevation approach. CBCT was used to measure the buccopalatal diameter (BPD), mesiodistal diameter (MDD), and hemi-ellipsoidal volume (Vh) in all sinuses. A bone core biopsy sample was taken at implant placement (4 to 5 months after sinus augmentation). Microradiographs of methacrylate-embedded sections were used to evaluate the amounts of bone, residual graft, and soft tissue. All 51 implants placed in the 39 patients successfully osseointegrated. A linear regression analysis showed that as BPD, MMD, and Vh increased, the amount of bone gain decreased and the amount of soft tissue increased (P < .05). The amount of residual graft was little affected by sinus morphology. Microradiographic data were grouped into four different sinus types (from small to great) using BPD and Vh medians. The best amount of bone formation was achieved in the narrow and short sinus type, while no great differences were found in the remaining three sinus types. Understanding of 3D sinus cavity morphology, especially the buccopalatal diameter and mesiodistal dimensions, is fundamental for achieving the best possible sinus augmentation outcomes.

Maxillary Sinus Floor Augmentation with Porcine-Apatite Xenograft: A Prospective Case Series Study.

This study clinically and histologically evaluated the outcome of a porcineapatite xenograft used to elevate the maxillary sinus floor in a severely atrophic ridge. A two-stage crestal window sinus elevation protocol was conducted in 24 patients with crestal bone ≤ 2 mm. Highly porous porcine carbonate apatite moistened with saline solution was placed in the elevated sinus cavity as the sole grafting material. Bone core biopsy samples were taken at 6, 9, and 12 months after sinus augmentation surgery (at implant placement). Treatment outcomes were assessed using microCT (µCT) and histologic analysis. Statistical analysis was performed using nonparametric Kruskal-Wallis test, followed by post-hoc Dunn multiple comparison test. At 6 months after implant placement, all implants achieved good primary stability (insertion torque ≥ 30 Ncm) and successfully osseointegrated. The residual graft amount (mean ± SE) was low (11.91% ± 1.99%) at 6 months and further decreased (6.11% ± 2.64%) by 12 months. On the contrary, the amount of new bone detected was 18.94% ± 4.08% at 6 months and was significantly (P < .05) increased (40.16% ± 5.27%) at 12 months. Histologic assessment revealed osteoclasts actively resorbing the graft as well as osteoblasts actively forming new bone. In the severely atrophic maxilla, the porcine-apatite xenograft promotes new bone formation while being slowly absorbed. Within the limited sample size, the porcine-apatite xenograft seems to be a good graft material for crestal window sinus augmentation.

Influence of apico-coronal positioning of tissue-level implants on marginal bone stability during supracrestal tissue height establishment: A multi-center prospective study.

INTRODUCTION: Supracrestal tissue height establishment is a crucial factor influencing peri-implant marginal bone modifications prior to prosthesis delivery. If mucosal thickness is insufficient, peri-implant marginal bone resorption occurs to allow appropriate supracrestal tissue height formation. This study evaluates if marginal bone resorption occurring around tissue-level implants before prosthetic loading could be compensated by adapting apico-coronal positioning to mucosal thickness. METHODS: Patients requiring placement of one single implant in the posterior mandible were treated with tissue-level implants with a 3-mm high transmucosal machined component and moderately rough implant body. Based upon vertical mucosal thickness measured after buccal flap reflection, implants were placed with the treated part: (group 1) 2 mm below crestal level in presence of thin mucosa (<2.5 mm); (group 2) 1 mm below the crestal level in presence of medium mucosa (2.5-3.5 mm); (group 3) at equicrestal level in presence of thick mucosa (>3.5 mm). RESULTS: Forty-nine implants, placed in 49 patients were included in final analysis (group 1: 18 implants; group 2: 16 implants; group 3: 15 implants). Mean marginal bone resorption after 5 months of healing was 0.66 ± 0.49 mm, 0.32 ± 0.41 mm, and 0.22 ± 0.52 mm in groups 1, 2, and 3, respectively. Inter-group analysis highlighted significant differences between the three groups after ANOVA test (p = 0.025). However, adaptation of apico-coronal implant positioning in relation to mucosal thickness, allowed to avoid early exposure of the treated surface in 100%, 93.7%, and 53.3% of the implants in groups 1, 2, and 3, respectively. CONCLUSION: During supracrestal tissue height formation, tissue-level implants inserted adapting apico-coronal positioning in relation to mucosal thickness exhibited greater marginal bone resorption at sites with thin mucosa than at sites with medium or thick mucosa. However, anticipating supracrestal tissue height establishment by adapting apico-coronal implant positioning in relation to mucosal thickness may effectively prevent unwanted exposure of treated implant surface.

Cortical Versus Cancellous Solvent-Dehydrated Bone Allograft for Alveolar Ridge Preservation: A Histologic Study.

Allografts have been routinely used for immediate grafting of extraction sites as modalities of alveolar ridge preservation (ARP). Solvent-dehydrated bone allograft (SDBA), which is commonly utilized for socket grafting, exists in the form of cortical and cancellous particles. This study aims to provide a histologic comparison of cortical and cancellous SDBA for ARP. A total of 35 extraction sockets were allocated to receive either a cortical (17 sites) or cancellous (18 sites) SDBA, followed by application of a resorbable collagen wound dressing in both groups. At approximately 4 months, a bone core biopsy sample was obtained during implant placement. Histomorphometric assessment was then conducted to compare the differences between both forms of SDBA. Within its limitations, a higher percentage of vital bone was observed in the cortical bone group compared to the cancellous bone group (28.6% vs 20.1%, respectively, P = .042), while there was a lack of statistically significant differences among other fractions of the bone biopsy sample (residual graft particles and nonmineralized tissues such as connective tissue or other components).

Topographic Assessment of Calcified Material After Sinus Floor Augmentation.

PURPOSE: This study aimed to topographically examine the healing of mineralized human bone allograft in sinus augmentation. MATERIALS AND METHODS: Thirty-two patients with crestal bone height ≤ 2 mm who required sinus augmentation were recruited for the study. A mixture of 80/20 cortical/cancellous mineralized human bone allografts were used to augment the sinus floor using a crestal window approach. A bone core biopsy specimen was taken at the time of implant placement, 6 months after surgery. Microradiographs of methacrylate-embedded sections were split into five longitudinal sectors (crestal to sinusal) to topographically assess the bone, graft, and fibrous tissue amount. RESULTS: All implants were osseointegrated 3 months later without any adverse effects. The polynomial (degree 2) of results (all with great correlation coefficient, P < .01) gave rise to a polynomial curve of graft percentage with a maximum at sector 4 (presinusal), a bone percentage with a minimum between sectors 3 and 4, and a fibrous tissue percentage with a maximum between sectors 3 and 4. CONCLUSION: Based upon topographic analysis, mineralized human bone allograft is capable of achieving adequate vertical bone height for implant placement. The need for a topographic analysis to assess the outcomes of sinus augmentation is emphasized.

Influence of Tooth-Brushing on Early Healing after Access Flap Surgery: A Randomized Controlled Preliminary Study.

In the present study, the clinical outcomes obtained using three different protocols of post-operative plaque control for the 4 weeks after surgery were compared. Thirty healthy subjects, presenting at least one periodontal pocket requiring resective surgery, were selected and randomly distributed to three different groups corresponding to respective post-surgical protocols: (A) toothbrushes + chlorhexidine + anti-discoloration system (ADS + CHX); (B) toothbrushes + chlorhexidine (CHX); (C) only toothbrushes. The full-mouth plaque score (FMPS), full-mouth bleeding score (FMBS), probing pocket depth (PPD), recession depth (REC), clinical attachment level (CAL), and bleeding on probing (BoP) were measured in six aspects per tooth (mesio-buccal (MB), buccal (B), disto-buccal (DB), disto-lingual (DL), lingual (L), and mesio-lingual (ML)) at baseline, 3 months, and 6 months after surgery. FMPS and FMBS did not significantly change (p > 0.05), whereas PPD and CAL significantly decreased, and REC significantly increased in all groups during the study (p < 0.05). Clinical results were satisfactory in all cases, with no significant differences between groups 3 months after surgery. Six months after surgery, only PPD-MB was significantly different in the three groups (p < 0.05). Nevertheless, this value was not clinically relevant because the value of PPD-B (about 2 mm) in group C was physiologic. The mechanical plaque control was proven to be fundamental and sufficient in all the six aspects per tooth to guarantee an excellent clinical outcome without the need of chemical plaque control.

Influence of abutment height and vertical mucosal thickness on early marginal bone loss around implants: A randomised clinical trial with an 18-month post-loading clinical and radiographic evaluation.

PURPOSE: To investigate the influence of vertical mucosal thickness on marginal bone loss around implants with short and long prosthetic abutments and the marginal bone loss progression rate up to 18 months after prosthetic loading. MATERIALS AND METHODS: Internal hex platform-switched implants were placed equicrestally using a two-stage protocol in the posterior mandible of two groups of patients with different vertical mucosal thickness, thin (≤ 2.0 mm) and thick (> 2.0 mm). Elevated prosthetic abutments of different heights (1 mm or 3 mm) were randomly assigned for single screw-retained crowns in both groups. Mesial and distal marginal bone loss were measured at implant placement (T0) and crown delivery (after 4 months [T1]), and after 6 (T2), 12 (T3) and 18 months (T4) of functional loading. RESULTS: Eighty implants were placed in eighty patients. Three patients dropped out at T2. At T4, 74 out of 77 implants were functioning, resulting in a 96% survival rate. Marginal bone loss (mean ± SE) at T2 was significantly greater in the 1-mm abutment groups (0.61 ± 0.09 mm with thin mucosa; 0.64 ± 0.07 mm with thick mucosa) than in the 3-mm abutment groups (0.32 ± 0.07 mm with thin mucosa; 0.26 ± 0.04 mm with thick mucosa). The marginal bone loss pattern over 18 months of loading showed that the greatest amount of marginal bone loss occurred during the first 6 months of function. CONCLUSIONS: Internal hex platform-switched implants placed equicrestally and restored with 1-mm abutments presented greater marginal bone loss than identical implants with 3-mm abutments, with vertical mucosal thickness having no significant influence.

Minimally Invasive Management of Implant-Supported Rehabilitation in the Posterior Maxilla, Part II. Surgical Techniques and Decision Tree.

Insufficient crestal bone is a common feature encountered in the edentulous posterior maxilla due to atrophy of the alveolar ridge and maxillary sinus pneumatization. Numerous surgical techniques, grafting materials, and timing protocols have been proposed for implant-supported rehabilitation of posterior maxillae with limited bone height. In the majority of potential implant sites, residual bone height is less than 8 mm and the clinician has to select either a lateral or transcrestal sinus-elevation technique or placing short implants as the correct surgical option. Nevertheless, guidelines for selecting the best option remains mostly based on the personal experience and skills of the surgeon. The role of sinus anatomy in healing and graft remodeling after sinus floor augmentation is crucial. In addition to the evaluation of residual bone height, the clinician should consider that histologic and clinical outcomes are also influenced by the buccal-palatal bone wall distance. Therefore, three main clinical scenarios may be identified and treated with either a lateral or transcrestal sinus-elevation technique or short implants. This article introduces a new decision tree for a minimally invasive approach based on current evidence to help the clinician safely and predictably manage implant-supported treatment of the atrophic posterior maxilla.

Minimally Invasive Management of Implant-Supported Rehabilitation in the Posterior Maxilla, Part I. Sinus Floor Elevation: Biologic Principles and Materials.

Alveolar bone resorption and maxillary sinus pneumatization occurring after dental extraction in the posterior region of the maxilla may be problematic when planning implant-supported rehabilitation. Various regenerative options are available, including guided bone regeneration, bone block grafts, and lateral sinus augmentation. These procedures are associated with significant complication rates, high morbidity, increased therapy duration, and high cost. Less invasive approaches, such as transcrestal sinus floor elevation, and using short implants have been proposed in an attempt to reduce these drawbacks. The aim of this study is to analyze available evidence to suggest predictable options and identify minimally invasive management of implant-supported rehabilitation in the posterior maxilla. This article concerns biologic mechanisms regulating new bone formation after maxillary sinus augmentation and examines characteristics of available implants and grafting materials to help the clinician select the most rational and convenient surgical approach according to specific situations.

Clinical and histological reaction of periodontal tissues to subgingival resin composite restorations.

OBJECTIVES: To compare the clinical and histological response of supracrestal periodontal tissues to subgingival composite restorations versus natural root surfaces MATERIAL AND METHODS: In 29 subjects with a single tooth requiring subgingival restorations, a deep margin elevation (DME) procedure with composite resin was applied. Full-mouth plaque score (FMPS), full-mouth bleeding score (FMBS), and focal probing depth (PD) were measured at baseline, before DME, and after 3 months. The distance between the coronal marked (CM) point to the apical margin of the composite reconstruction (AMR), at baseline, and to the tip of the periodontal probe inserted to reach the bottom of the sulcus (APP), 3 months later, was measured. An all-around secondary flap, harvested to ensure the subsequent single-crown prosthetic rehabilitation was histologically processed. The histological inflammation degree was evaluated in areas of gingival tissues adjacent to the composite (group B) and adjacent to the natural surface of each single tooth (group A). RESULTS: Significant FMPS, FMBS, and PD decreases were observed (p < 0.05). CM-AMR and CM-APP were significantly different (p < 0.05), suggesting an attachment gain after 3-months. The inflammation level of gingival tissue was similar in groups A and B (p > 0.05). CONCLUSIONS: For the first time, this topic was clinically and histologically studied in humans. Subgingival restorations resulted compatible with gingival health, with levels similar to that of untreated root surfaces. CLINICAL RELEVANCE: Deep margin elevation procedure produces favorable clinical and histological outcomes allowing a routine utilization in reconstructive dentistry.

Biological width establishment around dental implants is influenced by abutment height irrespective of vertical mucosal thickness: A cluster randomized controlled trial.

OBJECTIVE: Prosthetic abutment height and peri-implant mucosal thickness are considered factors that influence marginal bone remodeling during biological width establishment around dental implants. However, no clinical studies have evaluated their simultaneous effect on marginal bone loss (MBL). This study analyzes the influence of abutment height on MBL around implants surrounded by both thin and thick mucosa up to 12 months after prosthetic loading. MATERIAL AND METHODS: Seventy platform-switched implants with internal hex were placed equicrestally in two groups of patients with different vertical mucosal thickness: thin (≤2.0 mm) and thick mucosa (>2.0 mm). After three months of submerged healing, prosthetic abutments with a height of 1 mm (short) or 3 mm (long) were randomly assigned for single crown screwed restoration in both groups. MBL was evaluated on radiographs taken at implant placement (T0 ), restoration delivery (T1 ), and after 6 months (T2 ) and 12 months (T3 ) of loading. RESULTS: After 12 months of loading, 66 implants were functioning (two dropouts, two failures), resulting in a 97% survival rate. Compared with T0 , mean MBL at T3 ranged between 0.59 and 0.80 mm in short abutment groups and between 0.28 and 0.37 mm in long abutment groups. Differences resulted statistically significant, irrespective of vertical peri-implant mucosal thickness. The MBL pattern over time showed the greatest amount of bone resorption in the first 6 months after loading, particularly around implants with short abutments. CONCLUSIONS: Platform-switched implants restored with short abutments present greater marginal bone loss than identical implants with long abutments, without significant peri-implant mucosal thickness effects.

Mechanisms of Hydrogen Sulfide against the Progression of Severe Alzheimer's Disease in Transgenic Mice at Different Ages.

Backgroud: Alzheimer disease is an age-related severe neurodegenerative pathology. The level of the third endogenous gas, hydrogen sulfide (H2S), is decreased in the brain of Alzheimer's disease (AD) patients compared with the brain of the age-matched normal individuals; also, plasma H2S levels are negatively correlated with the severity of AD. Recently, we have demonstrated that systemic H2S injections are neuroprotective in an early phase of preclinical AD. OBJECTIVES: This study focuses on the possible neuroprotection of a chronic treatment with an H2S donor and sulfurous water (rich of H2S) in a severe transgenic 3×Tg-AD mice model. METHOD: 3×Tg-AD mice at 2 different ages (6 and 12 months) were daily treated intraperitoneally with an H2S donor and sulfurous water (rich of H2S) for 3 months consecutively. We investigated the cognitive ability, brain morphological alterations, amyloid/tau cascade, excitotoxic, inflammatory and apoptotic responses. RESULTS: Three months of treatments with H2S significantly protected against impairment in learning and memory in a severe 3×Tg-AD mice model, at both ages studied, and reduced the size of Amyloid ß plaques with preservation of the morphological picture. This neuroprotection appeared mainly in the cortex and hippocampus, associated with reduction in activity of c-jun N-terminal kinases, extracellular signal-regulated kinases and p38, which have an established role not only in the phosphorylation of tau protein but also in the inflammatory and excitotoxic response. CONCLUSION: Our findings indicate that appropriate treatments with various sources of H2S, might represent an innovative approach to counteract early and severe AD progression in humans.

Bone Regeneration by Novel Bioactive Glasses Containing Strontium and/or Magnesium: A Preliminary In-Vivo Study.

In this work, a set of novel bioactive glasses have been tested in vivo in an animal model. The new compositions, characterized by an exceptional thermal stability and high in vitro bioactivity, contain strontium and/or magnesium, whose biological benefits are well documented in the literature. To simulate a long-term implant and to study the effect of the complete dissolution of glasses, samples were implanted in the mid-shaft of rabbits' femur and analyzed 60 days after the surgery; such samples were in undersized powder form. The statistical significance with respect to the type of bioactive glass was analyzed by Kruskal⁻Wallis test. The results show high levels of bone remodeling, several new bone formations containing granules of calcium phosphate (sometimes with amounts of strontium and/or magnesium), and the absence of adverse effects on bone processes due to the almost complete glass dissolution. In vivo results confirming the cell culture outcomes of a previous study highlighted that these novel bioglasses had osteostimulative effect without adverse skeletal reaction, thus indicating possible beneficial effects on bone formation processes. The presence of strontium in the glasses seems to be particularly interesting.

Gingival tissue reaction to direct adhesive restoration: A preliminary study.

INTRODUCTION: It is debated whether composite resin marginal/submarginal direct restoration can be usefully performed without inflammatory consequences. This histological study is the first human analysis aimed to compare, in the same tooth, the gingival tissue close to composite resin restorations with gingival tissue close to hard tissue. METHODS: Eight healthy patients with almost a residual strategic tooth needing endodontic therapy, and post-and-core restoration, then indirect prosthetic restoration, were selected. Direct margin relocation with composite resin was necessary to perform endodontic treatment. The crown lengthening with a secondary flap harvested was necessary to perform prosthetic rehabilitation. Three months after marginal relocation, the secondary flap was harvested, embedded in PMMA, 4-µm sectioned, and stained to analyze the inflammation degree. RESULTS: All patients completed post-and-core reconstruction and the planned prosthetic therapy, maintaining the stringent hygienic protocol plan. The inflammation level comparison, slightly lower in gingiva close to the teeth (3.62 ± 0.38) than in gingiva close to the composite (3.75 ± 0.26), results in a p-value of 0.11 after Wilcoxon test. CONCLUSIONS: Results highlight a minimal, statistically not significant difference in the inflammation degree after margin relocation, conceivably due to patients, teeth and cases selection, together with adopted stringent methodological and supportive measures.

Are periodontal outcomes affected by personality patterns? A 18-month follow-up study.

OBJECTIVES: This research aims to study the relationship between personality traits and periodontal clinical outcomes by taking into account the level of anxiety and depression, periodontal health and oral hygiene behaviour of patients affected with gingivitis or moderate periodontitis requiring periodontal therapy. MATERIAL AND METHODS: The periodontal data of 40 systemically healthy patients affected by gingivitis or moderate periodontitis were collected at baseline and 18 months later. The psychological variables, dental awareness and adherence intent of the patients were assessed through questionnaires, and only those patients that exhibited a higher degree of compliance were included in the study. The personality traits (cluster A: paranoid, schizoid, schizotypal; cluster B: borderline, antisocial, narcissistic, and histrionic; cluster C: avoidant, dependent, and obsessive-compulsive) and the level of anxiety and depression of the patients were assessed. Patients were instructed with oral hygiene measures and were treated with periodontal therapy. RESULTS: Clusters A and B showed a consistent tendency for reduced levels of oral hygiene (increased full-mouth plaque score - FMPS). The results from cluster B were found to be significantly related to deep periodontal pockets at baseline. On the contrary, cluster C seemed to be linked to clinically better indices, particularly in terms of full-mouth-bleeding-score and pocket depth, both at baseline and 18 months later. The results collected from clusters B and C were directly correlated with anxiety, depression and FMPS. Moreover, anxiety was directly correlated with the patient's need for professional oral-care. CONCLUSIONS: Personality traits appear to play a significant role in determining the therapeutic outcomes of periodontal therapy in themselves. Thus, it is ideal for several important psychological, affective or behavioural factors to be associated with various personality traits so as to orient the outcome of periodontal therapy.

Minimum Abutment Height to Eliminate Bone Loss: Influence of Implant Neck Design and Platform Switching.

PURPOSE: This retrospective study quantitatively analyzed the minimum prosthetic abutment height to eliminate bone loss after 4.7-mm-diameter implant placement in maxillary bone and how grafting techniques can affect the marginal bone loss in implants placed in maxillary areas. MATERIALS AND METHODS: Two different implant types with a similar neck design were singularly placed in two groups of patients: the test group, with platform-switched implants, and the control group, with conventional (non-platform-switched) implants. Patients requiring bone augmentation underwent unilateral sinus augmentation using a transcrestal technique with mineralized xenograft. Radiographs were taken immediately after implant placement, after delivery of the prosthetic restoration, and after 12 months of loading. RESULTS: The average mesial and distal marginal bone loss of the control group (25 patients) was significantly more than twice that of the test group (26 patients), while their average abutment height was similar. Linear regression analysis highlighted a statistically significant inverse relationship between marginal bone loss and abutment height in both groups; however, the intercept of the regression line, both mesially and distally, was 50% lower for the test group than for the control group. The marginal bone loss was annulled with an abutment height of 2.5 mm for the test group and 3.0 mm for the control group. No statistically significant differences were found regarding marginal bone loss of implants placed in native maxillary bone compared with those placed in the grafted areas. CONCLUSION: The results suggest that the shorter the abutment height, the greater the marginal bone loss in cement-retained prostheses. Abutment height showed a greater influence in platform-switched than in non-platform-switched implants on the limitation of marginal bone loss.

How Intraday Index Changes Influence Periodontal Assessment: A Preliminary Study.

It is reputed that periodontal indices remain unchanged over a 24-hour period, with great clinical significance. This preliminary study analyzes daily index changes. In 56 selected patients, full-mouth plaque score (FMPS), full-mouth bleeding score (FMBS), periodontal screening and recording (PSR) indices, and periodontal risk assessment (PRA) were recorded at baseline and three times per day (check-I: 08.30, check-II: 11.30, and check-III: 14.30), after appropriate cause-related therapy. Correlation between variables was statistically analyzed by Stata. All periodontal indices improved at the examination phase. Statistical differences were detected for FMPS comparing all thrice daily checks. Statistical differences were detected for FMBS and PRA comparing check-III with check-I and check-II. PSR showed no significant changes. The worst baseline indices produced the widest daily fluctuation at the examination phase. Significant variation of indices is directly related to clinical severity of periodontal conditions at baseline. Patients affected by severe periodontal disease may show significantly greater index changes. As indices are routinely recorded only once per day, the index daily variation has clinical significance. This greatly affects therapeutic strategy as correct periodontal assessment requires multiple evaluations at standardized times, particularly when baseline conditions are severe.

Hybrid and fully-etched surface implants in periodontally healthy patients: A comparative retrospective study on marginal bone loss.

BACKGROUND: Human studies on implants with the same design but with different surfaces are lacking at the present time. PURPOSE: The aim of this study was to compare the survival rate of and marginal bone loss (MBL) around 2 types of implants with the same design, but with different surfaces: fully "sandblasted and double-etched" (SDE) implants and hybrid (H) implants, with an apical SDE-surface and a coronal machined-surface. MATERIALS AND METHODS: The SDE- and H-surfaces were previously analyzed under SEM and profilometer. Implants were placed in partially edentulous periodontally healthy patients requiring single implant-restoration, in either mandible or maxilla, with cement-retained prosthetic restoration. Twelve months after prosthetic loading, MBL in relation to prosthetic abutment height (AH), calculated radiographically, was statistically analyzed. RESULTS: SEM and profilometer analyses revealed no differences between the SDE-surfaces of either SDE- or H-implants. Transverse ridges and grooves characterized the machined portion of H-implants, clearly influencing the profilometer analysis. In 75 patients, 37 SDE and 38 H-implants were placed and all functioned completely after 12 months. In both SDE- and H-groups, MBL had a significant inverse relationship with AH, with greater intercept and negative slope for SDE-group and intersection of the 2 regression lines at AH = 2 mm. CONCLUSIONS: A 100% survival rate was recorded for SDE- and H-implants placed in pristine bone of periodontally healthy patients; MBL was limited and similar in both SDE- and H-groups; the higher the prosthetic AH, the lesser the MBL around implants; H-implants could reduce bone loss most effectively with abutments lower than 2 mm, realistically exploitable on thin biotypes; SDE-implants could reduce bone loss most effectively with abutments greater than 2 mm, realistically exploitable on thick biotypes.