Carlo Cafiero

A 10-year retrospective analysis of marginal bone-level changes around implants in periodontally healthy and periodontally compromised tobacco smokers

AIM to compare the 10-year marginal bone loss rates around implants supporting single-unit crowns in tobacco smokers with and without a history of treated periodontitis. MATERIALS AND METHODS in this retrospective controlled study, 40 tobacco smokers were divided into four groups of 10 patients each. Two groups of periodontally compromised (PC) patients and two groups of periodontally healthy (PH) patients were established. PC patients had been treated for their periodontal conditions before implant placement. All patients were enrolled in a regular, individually tailored maintenance care program. For the rehabilitation of PC and PH patients, two different types of implants were used (Nobel Biocare AB; Straumann Dental Implant System). The radiographic bone loss rate was calculated by subtracting the bone levels at the time of crown delivery from the bone levels at the 10-year follow-up. RESULTS the mean age, mean full-mouth plaque score and full-mouth bleeding score and implant location were similar for the four groups. Implant survival rates ranged between 70% and 100%, without statistically significant differences between the four groups (P>0.05). Implants placed in PC patients yielded statistically significantly higher marginal bone loss rates compared with those in PH patients (P<0.05), independent of the implant system used. CONCLUSION after 10 years, implants placed in tobacco smokers with a history of treated periodontitis and enrolled in a supportive therapy program yielded lower survival rates and higher marginal bone loss rates compared with those of implants placed in PH smokers. These outcomes were independent of the implant system installed or the healing modality applied.

Grain reserves and food security in the Middle East and North Africa

Aggregate stocks of major grains declined to minimal feasible levels in 2007–2008, due to high global income growth and biofuel mandates. Given these minimal stocks, prices were very sensitive to shocks, such as the Australian drought, and biofuel demand boosts due to the oil price spike. The effects of these shocks were magnified by a sequence of trade restrictions by key exporters to protect vulnerable consumers. Beginning in the ‘thin’ global rice market in the fall of 2007, these turned market anxiety into panic. Recognizing the unreliability of imports, vulnerable countries, including some in the Middle East and North Africa (MENA), are now considering investing in strategic reserves, pursuing self sufficiency and acquiring foreign land to ensure grain supplies for domestic consumption. The associated expense and negative incentive effects on national reserves may be acceptable if they have quantitative targets related to the needs of the most vulnerable, for distribution only in emergencies. In many MENA countries, heavy subsidies on grain consumption for both rich and poor reduce the stabilizing response of consumption to price, and increase reserves needed to ensure food security. Accumulation of stocks is a more efficient strategy than pursuit of self-sufficiency in most MENA countries, as they have no comparative advantage in expanding agriculture, given restricted water supplies. Acquisition of foreign lands leaves food supplies exposed to sovereign risk and other supply chain problems beyond importers’ control. MENA countries could cooperate and so smooth much of the risk posed by fluctuations in their own harvests.

Immediate transmucosal implant placement in molar extraction sites: a 12‐month prospective multicenter cohort study

AIM To assess the clinical and radiographic outcomes of immediate transmucosal placement of implants into molar extraction sockets. STUDY DESIGN Twelve-month multicenter prospective cohort study. MATERIAL AND METHODS Following molar extraction, tapered implants with an endosseous diameter of 4.8 mm and a shoulder diameter of 6.5 mm were immediately placed into the sockets. Molars with evidence of acute periapical pathology were excluded. After implant placement and achievement of primary stability, flaps were repositioned and sutured allowing a non-submerged, transmucosal healing. Peri-implant marginal defects were treated according to the principles of guided bone regeneration (GBR) by means of deproteinized bovine bone mineral particles in conjunction with a bioresrobable collagen membrane. Standardized radiographs were obtained at baseline and 12 months thereafter. Changes in depth and width of the distance from the implant shoulder (IS) and from the alveolar crest (AC) to the bottom of the defect (BD) were assessed. RESULTS Eighty-two patients (42 males and 40 females) were enrolled and followed for 12 months. They contributed with 82 tapered implants. Extraction sites displayed sufficient residual bone volume to allow primary stability of all implants. Sixty-four percent of the implants were placed in the areas of 36 and 46. GBR was used in conjunction with the placement of all implants. No post-surgical complications were observed. All implants healed uneventfully yielding a survival rate of 100% and healthy soft tissue conditions after 12 months. Radiographically, statistically significant changes (P<0.0001) in mesial and distal crestal bone levels were observed from baseline to the 12-month follow-up. CONCLUSIONS The findings of this 12-month prospective cohort study showed that immediate transmucosal implant placement represented a predictable treatment option for the replacement of mandibular and maxillary molars lost due to reasons other than periodontitis including vertical root fractures, endodontic failures and caries.

Validity and reliability of food security measures.

This paper reviews some of the existing food security indicators, discussing the validity of the underlying concept and the expected reliability of measures under reasonably feasible conditions. The main objective of the paper is to raise awareness on existing trade‐offs between different qualities of possible food security measurement tools that must be taken into account when such tools are proposed for practical application, especially for use within an international monitoring framework. The hope is to provide a timely, useful contribution to the process leading to the definition of a food security goal and the associated monitoring framework within the post‐2015 Development Agenda.

Crestal bone changes at teeth and implants in periodontally healthy and periodontally compromised patients. A 10-year comparative case-series study.

BACKGROUND Limited data exist on the longitudinal crestal bone changes around teeth compared with implants in partially edentulous patients. This study sought to compare the 10-year radiographic crestal bone changes (bone level [BL]) around teeth and implants in periodontally compromised (PCPs) and periodontally healthy (PHPs) patients. METHODS A total of 120 patients were evaluated for the radiographic crestal BL around dental implants and adjacent teeth at time of implant crown insertion and at the 10-year follow-up. Sixty patients had a previous history of periodontitis (PCPs), and the remaining 60 were PHPs. In each category (PCP and PHP), two different implant systems were used. The mean BL change at the implant and at the adjacent tooth at the interproximal area was calculated by subtracting the radiographic crestal BL at the time of crown cementation from the radiographic crestal BL at the 10-year follow-up. RESULTS At 10 years after therapy, the survival rate ranged from 80% to 95% for subgroups for implants, whereas it was 100% for the adjacent teeth. In all eight different patient categories evaluated, teeth demonstrated a significantly more stable radiographic BL compared with adjacent dental implants (teeth BL, 0.44 ± 0.23 mm; implant BL, 2.28 ± 0.72 mm; P <0.05). Radiographic BL changes around teeth seemed not to be influenced by the presence or absence of advanced bone loss (≥3 mm) at the adjacent implants. CONCLUSIONS Natural teeth yielded better long-term results with respect to survival rate and marginal BL changes compared with dental implants. Moreover, these findings also extend to teeth with an initial reduced periodontal attachment level, provided adequate periodontal treatment and maintenance are performed. As a consequence, the decision of tooth extraction attributable to periodontal reasons in favor of a dental implant should be carefully considered in partially edentulous patients.

Dimensional ridge alterations following immediate implant placement in molar extraction sites: a six-month prospective cohort study with surgical re-entry

AIM To assess dimensional ridge alterations following immediate implant placement in molar extraction sites. MATERIAL AND METHODS Twelve subjects received 12 immediate transmucosal implants in molar extraction sites. Peri-implant defects were treated according to the principles of Guided Bone Regeneration by means of a deproteinized bone substitute and a bioresorbable collagen membrane. Changes in vertical (IS-BD, CREST-BD) and horizontal distances (EC-I, IC-I) of alveolar bony walls to the bottom of the defects (BD) and to the implant surfaces (I) were compared between implant placement and surgical re-entry at 6 months. RESULTS The implant survival rate at 6 months was 100%. Statistically significant differences (P<0.01) were observed in the mean changes in vertical distances IS-BD and CREST-BD between baseline and re-entry. At re-entry, all peri-implant marginal defects assessed from the internal socket wall to the implant surface (IC-I) were healed. The residual combined thickness of the buccal wall with the newly formed peri-implant bone at sites with an initial thickness of 1 mm was statistically significantly smaller (P<0.05) compared with that of sites with an initial buccal thickness of 2 mm (2.50 +/- 0.76 vs. 4+/-0 mm). CONCLUSIONS The marginal defects around immediate implants placed in molar extraction sites were completely filled after 6 months of healing through de novo bone formation. Bone resorption was observed from the external aspects of the buccal and oral socket walls. Dimensional changes of the external socket walls were mostly pronounced at the buccal aspects.

Sublingual ranula: a closer look to its surgical management.

Ranulas have been managed by various surgical methods, and the optimal treatment is still controversial. The aim of this study was to analyze a group of 124 surgically treated patients with intraoral ranula to assess 3 different methods: sublingual gland removal combined with the ranula excision, conventional marsupialization, and a variant of the marsupialization technique usually performed in our departments. Recurrence rate was 0% after radical treatment, 25.8% after marsupialization, and 12% after modified marsupialization. We suggest that conservative methods should always be considered as treatment of superficial oral ranulas. The modification of the conventional marsupialization by suturing the edges of the pseudocyst before unroofing of the lesion was demonstrated to be a useful technical strategy that simplifies and accelerates the surgical procedures and probably contributed to preventing recurrences.

Predictive, preventive, personalised and participatory periodontology: 'the 5Ps age' has already started.

An impressive progress in dentistry has been recorded in the last decades. In order to reconsider guidelines in dentistry, it is required to introduce new concepts of personalised patient treatments: the wave of predictive, preventive and personalised medicine is rapidly incoming in dentistry. Worldwide dentists have to make a big cultural effort in changing the actual ‘reactive’ therapeutic point of view, belonging to the last century, into a futuristic ‘predictive’ one. The first cause of tooth loss in industrialised world is periodontitis, a Gram-negative anaerobic infection whose pathogenesis is genetically determined and characterised by complex immune reactions. Chairside diagnostic tests based on saliva, gingival crevicular fluid and cell sampling are going to be routinely used by periodontists for a new approach to the diagnosis, monitoring, prognosis and management of periodontal patients. The futuristic ‘5Ps’ (predictive, preventive, personalised and participatory periodontology) focuses on early integrated diagnosis (genetic, microbiology, host-derived biomarker detection) and on the active role of the patient in which networked patients will shift from being mere passengers to responsible drivers of their health. In this paper, we intend to propose five diagnostic levels (high-tech diagnostic tools, genetic susceptibility, bacterial infection, host response factors and tissue breakdown-derived products) to be evaluated with the intention to obtain a clear picture of the vulnerability of a single individual to periodontitis in order to organise patient stratification in different categories of risk. Lab-on-a-chip (LOC) technology may soon become an important part of efforts to improve worldwide periodontal health in developed nations as well as in the underserved communities, resource-poor areas and poor countries. The use of LOC devices for periodontal inspection will allow patients to be screened for periodontal diseases in settings other than the periodontist practice, such as at general practitioners, general dentists or dental hygienists. Personalised therapy tailored with respect to the particular medical reality of the specific stratified patient will be the ultimate target to be realised by the 5Ps approach. A long distance has to be covered to reach the above targets, but the pathway has already been clearly outlined.

Maximum Likelihood Estimation of the Standard Commodity Storage Model. Evidence from Sugar Prices

We present a Maximum Likelihood estimator for the standard commodity storage model with stockouts, based on prices only. While it imposes no additional assumptions on the model, the Maximum Likelihood estimator has small sample properties superior to those of the Pseudo Maximum Likelihood approach. We provide a proof that is crucial for applying our estimator to the model with normal harvests and possibly unbounded prices, thereby eliminating an inconsistency in the empirical storage model literature. Applying our Maximum Likelihood estimator to a series of annual sugar prices from 1921 to 2009 provides new evidence for the empirical relevance of the standard storage model. Our results imply a cutoff price at which discretionary stocks go to zero, which is higher than the price obtained by applying the Pseudo Maximum Likelihood estimator to the same data. The implied frequency of stockouts is lower, and price correlations, skewness, and kurtosis implied by the model closely match those seen in the annual sugar price data. We find the price of sugar to be highly responsive to small changes in consumption. When inventories are not available to buffer the effects of negative supply shocks on consumption, prices must increase sharply to induce the consumption changes needed to clear the market. Our results show why production shocks are not necessarily aligned with price spikes; the same production shock can give rise to very different price responses, depending on whether or not there are sufficient stocks to buffer its impact.

Does market competitiveness significantly affect public intervention in agricultural insurance: the case in Italy

Analyses of agricultural insurance failures often assume the existence of competitive supply, tracing the reasons for high insurance cost and limited farmer participation to informational problems, and suggesting the need for premium subsidization in order to increase participation. However, in countries such as Spain and Italy, where agricultural insurance is most highly subsidized, it could be that supply is not fully competitive. In this article, we explore the incidence of public subsidies to agricultural insurance premia when supply is noncompetitive. Through the use of a simple empirical model of an insurance market, it is shown that, while in the case of a competitive supply, subsidies to insurance would benefit farmers, a monopolistic supply would capture most of the subsidy, thus eliminating the potential incentive towards wider participation by farmers. The model is applied to a panel of Italian farms for different levels of risk aversion to demonstrate the limited effect that a subsidy to a hypothetical all risk yield insurance would have on farmer participation in the case of monopolistic supply.