Stefano Mummolo

Periodontal disease: The influence of metabolic syndrome

Metabolic syndrome (MetS) is a cluster of cardiovascular risk factors that include obesity, impaired glucose tolerance or diabetes, hyperinsulinemia, hypertension, and dyslipidemia. Recently, more attention has been reserved to the correlation between periodontitis and systemic health. MetS is characterized by oxidative stress, a condition in which the equilibrium between the production and the inactivation of reactive oxygen species (ROS) becomes disrupted. ROS have an essential role in a variety of physiological systems, but under a condition of oxidative stress, they contribute to cellular dysfunction and damage. Oxidative stress may act as a common link to explain the relationship between each component of MetS and periodontitis. All those conditions show increased serum levels of products derived from oxidative damage, promoting a proinflammatory state. Moreover, adipocytokines, produced by the fat cells of fat tissue, might modulate the balance between oxidant and antioxidant activities. An increased caloric intake involves a higher metabolic activity, which results in an increased production of ROS, inducing insulin resistance. At the same time, obese patients require more insulin to maintain blood glucose homeostasis – a state known as hyperinsulinemia, a condition that can evolve into type 2 diabetes. Oxidation products can increase neutrophil adhesion and chemotaxis, thus favoring oxidative damage. Hyperglycemia and an oxidizing state promote the genesis of advanced glycation end-products, which could also be implicated in the degeneration and damage of periodontal tissue. Thus, MetS, the whole of interconnected factors, presents systemic and local manifestations, such as cardiovascular disease and periodontitis, related by a common factor known as oxidative stress.

Efficacy of essential oil mouthwash with and without alcohol: a 3-Day plaque accumulation model

BackgroundThe aim of this study was to evaluate the antiplaque effect of a new alcohol free essential oil mouthwash with respect to a control of an essential oil with alcohol mouthwash, using an in vivo plaque regrowth model of 3-days.MethodsThe study was designed as a double-masked, randomized, crossover clinical trial, involving 30 volunteers to compare two different essential oil containing mouthwashes, during a 3-day plaque accumulation model. After receiving a thorough professional prophylaxis at the baseline, over the next 3-days each volunteer refrained from all oral hygiene measures and had two daily rinses with 20 ml of the test mouthwash (alcohol free essential oil) or the control mouthwash (essential oil with alcohol). At the end of the each experimental period, plaque was assessed and the panelists filled out a questionnaire. Each subject underwent a 14 days washout period and there was a second allocation.ResultsThe essential oil mouthwash with ethanol shows a better inhibitory effect of plaque regrowth in 3-days than the mouthwash test with only essential oil in the whole mouth (plaque index = 2.18 against 2.46, respectively, p < 0.05); for the lower jaw (plaque index = 2.28 against 2.57, respectively, p < 0.05); for the upper jaw (plaque index = 2.08 against 2.35, respectively, p < 0.05); for the incisors (plaque index = 1.93 against 2.27, respectively, p < 0.05); and the canines (plaque index = 1.99 against 2.47, respectively, p < 0.05).ConclusionThe essential oil containing mouthwash without alcohol seems to have a less inhibiting effect on the plaque regrowth than the traditional alcoholic solution.Trial RegistrationClinicalTrials.gov NCT01411618

In-office bacteria test for a microbial monitoring during the conventional and self-ligating orthodontic treatment

This study investigated the microbial level of Streptococcus mutans and Lactobacillus spp. during an orthodontic treatment, and compare the data with untreated control subjects.Sixty young adult subjects were selected (average 20.5, DS 1.62), among which 40 underwent an orthodontic treatment (20 were treated with self-ligating brackets and 20 with conventional brackets) and 20 were controls. Plaque Index, salivary flow and buffering capacity of saliva were assessed before the beginning of the orthodontic treatment. Then the microbial counts were obtained by using an in-office bacteria test.The plaque index (PI) increased over time in each group as well as salivary flow, mostly in subjects treated with self-ligating brackets, suggesting a difference between conventional and self-ligating brackets. S.mutans showed a different trend of colonization in the two treated groups, as for subjects treated with conventional brackets it showed the greater value at the early stage of treatment (T1), followed by a decrease at T2. Lactobacillus spp. showed significant increase over time in the two treated groups, respect to the control group. Linear regression analysis showed no significant predictor for the microbial count at T2.The assortment of the various species of bacteria change over time during the orthodontic treatment, and seems to show different trends, depending on the type of orthodontic device. Consequently a periodical microbial monitoring using in-office bacteria tests, seems indicated.

Application of a quartz microbalance based gas sensor array for the study of halitosis

Research into the monitoring and control of oral malodor has nowadays received new stimulus from the importance gained by this phenomenon as a medical and social problem. In this paper the performance of an electronic nose to detect this manifestation has been investigated in order to explore the possibility of using this instrument as a complement to those already existing for the assessment of oral malodor. In particular, a breath sampling procedure has been optimized to maximize the transfer to the sensors of those molecules that are known to be associated with the malodor. The sensitivity of electronic nose sensors to hydrogen sulfide, butyric acid and valeric acid-three compounds known to play a major role in halitosis-has been measured and the results indicate that the threshold limits are compatible with halitosis detection. An experiment with real and artificial samples indicates the possibility of identifying halitosis-affected individuals and of discriminating them according to breath composition.

Microleakage of bacteria in different implant-abutment assemblies: an in vitro study

Purpose The aim of the present in vitro study was to evaluate the leakage observed for 2 different microbial species at the level of the implant–abutment (I-A) interface, and the marginal fit and size of microgap at the I-A interface in 2 different implant connections. Methods Ten specimens of each group were tested. The inner parts of 5 implants per group were inoculated with 0.1 μL of a viable Enterococcus faecalis suspension and 5 implants per group with Aggregatibacter actinomycetemcomitans. All of the vials containing the control specimens were incubated at 37°C under aerobic condition for E. faecalis and 37°C in presence of 5% CO2 for A. actinomycetemcomitans. They were maintained for 14 days, and the possible penetration of bacterial suspension into the surrounding solution was determined by the observation of turbidity of the broth. The I-A interface was evaluated for size of microgap and measured under SEM. Five implants of each group were evaluated. The marginal fit between implant and abutment was measured at 8 random locations in each assembly, under different magnifications at the interface. Results No leakages through the I-A interface were demonstrated for either type of connection evaluated. The microgap values of all I-A interfaces ranged from 0.008 to 2.009 μm; the differences between the 2 systems were statistically significant. Conclusions The present study demonstrated that a good marginal fit of implant components seemed to be able to prevent bacterial leakage.

sEMG activity of masticatory, neck, and trunk muscles during the treatment of scoliosis with functional braces. A longitudinal controlled study

BACKGROUND Studies on the relationship between occlusal problems and the spine are of increasing interest. In this study, we monitored the sEMG activity of masticatory, neck, and trunk muscles during the treatment of scoliosis in young patients, and compared the data with a control of untreated group. SUBJECTS AND METHODS Twelve white Caucasian patients (nine males and three females; mean age of 8.0±1.5 years) with scoliosis and Class I occlusion (without crowding) were included in this study (study group). Fifteen healthy subjects (nine males and six females; mean age of 9.5±0.8 years) were recruited as control group. The subjects were visited before they underwent the treatment of scoliosis, as well as after 3 (T1) and 6 months (T2) of their treatment for scoliosis. The patients were instructed to wear the device during sleep and during the day, according to the protocol given by their orthopedic. RESULTS The treated group showed statistically significant changes in the sEMG activity of masticatory, neck, and trunk muscles, both at rest and during MVC of the mandible with respect to T0. The masseter and the anterior temporalis showed a significant improvement in the asymmetry index from T0 to T2. On the other hand, subjects in the control group did not register much change. CONCLUSION Our findings suggest that the use of a functional device for the treatment of scoliosis induces a significant reduction in the asymmetry index of the trunk muscles, as well as a significant increase in the contractility of masticatory muscles.

Evaluation of an Endosseous Oral Implant System According to Uni En Iso 14801 Fatigue Test Protocol

Purpose:The aim of this in vitro study was to evaluate the maximum fracture load and the mechanical performance to cyclic fatigue stress of a dental implant system. Methods:An experimental study according to the international standards (UNI EN ISO 14801: 2008) was carried out using 15 implants (3.80 mm of diameter and 13 mm of length) with applied straight titanium abutment tightened to 30 N. Five samples were subjected to compression stress at break. Based on the mean fracture load value obtained in this test, the levels of dynamic loading range were set that were carried on at a frequency of 15 Hz for 5 × 106 cycles. Results:The compression stress at break mean value of the tested implants was 499.40 N (SD ±50.1 N). In the mechanical fatigue stress test, the fatigue limit for 5 × 106 load cycles for all tested samples was 250 N. Conclusions:The evaluated implant system proved to withstand considerable mechanical loads under the “worst-case” loading situation performed according to UNI EN ISO 14801 standard. The reliability of this test protocol makes it suitable to be accomplished for understanding and comparing mechanical properties of other implant systems.

Orthodontic treatment of an unerupted mandibular canine tooth in a patient with mixed dentition: a case report

BackgroundThe aim of this case report was to describe the surgical–orthodontic treatment of an unerupted mandibular canine tooth in a 9-year-old girl.Case presentationA 9-year-old white girl presented with an unerupted right mandibular canine tooth. Combined surgical–orthodontic treatment was performed to correct dental impaction and to achieve good aesthetic and functional results.ConclusionOrthodontic treatment achieved all of the required objectives.

Mechanical Reliability Evaluation of an Oral Implant-Abutment System According to UNI EN ISO 14801 Fatigue Test Protocol

Purpose:The aim of this in vitro study was to evaluate the mechanical reliability of a dental implant system by testing its maximum fracture load and mechanical performance under cyclic fatigue stress. Methods:An experimental study according to the international standards (UNI EN ISO 14801: 2008) was performed using 13 implants (3.80 mm in diameter and 12 mm in length) with straight titanium abutments tightened to 30 N. Five samples were subjected to compression stress at break. Based on the mean fracture load value obtained in this test, the levels of dynamic loading range were set and were carried on at a frequency of 15 Hz for 5 × 106 cycles. Results:The compression stress at break mean value of the tested implants was 430 N (SD ± 35.66 N). In the mechanical fatigue stress test, the fatigue limit for 5 × 106 load cycles was 172 N. Conclusions:The evaluated implant system proved to withstand considerable mechanical loads under the “worst-case” loading situation performed according to UNI EN ISO 14801 standard. The reliability of this test protocol makes it suitable to be accomplished for understanding and comparing mechanical properties of implant systems.

Frenulectomy of the tongue and the influence of rehabilitation exercises on the sEMG activity of masticatory muscles

This study aimed to assess by surface electromyography (sEMG) the changes in sub-mental, orbicularis oris, and masticatory muscle activity after a lingual frenulectomy. Rehabilitation exercises in subjects with ankyloglossia, characterized by Class I malocclusion, were assessed as well. A total of 24 subjects were selected. Thirteen subjects (mean age 7±2.5years) with Class I malocclusion and ankyloglossia were treated with lingual frenulectomy and rehabilitation exercises, while 11 subjects (mean age 7±0.8years) with normal occlusion and normal lingual frenulum were used as controls. The inclusion criteria for both groups were the presence of mixed dentition and no previous orthodontic treatment. The sEMG recordings were taken at the time of the first visit (T0), and after 1 (T1) and 6months (T2) for the treated group. Recordings were taken at the same time for the control group. Due to the noise inherent with the sEMG recording, special attention was paid to obtain reproducible and standardized recordings. The tested muscles were the masseter, anterior temporalis, upper and lower orbicularis oris, and sub-mental muscles. The sEMG recordings were performed at rest, while kissing, swallowing, opening the mouth, clenching the teeth and during protrusion of the mandible. These recordings were made by placing electrodes in the area of muscle contraction. At T0, the treated group showed different sEMG activity of the muscles with respect to the control group, with significant differences at rest and during some test tasks (p<0.05). In the treated group, an increase in sEMG potentials was observed for the masseter muscle, from T0 to T2, during maximal voluntary clenching. During swallowing and kissing, the masseter and sub-mental muscles showed a significant increase in their sEMG potentials from T0 to T2. During the protrusion of the mandible, the masseter and anterior temporalis significantly decreased their sEMG activity, while the sub-mental area increased significantly. No significant change was observed in the control group during the follow-up. The sEMG potentials of treated patients at T2 reached about the same values as those of the control group at T2. At T0 and T1 the differences between the two groups were more diffused, suggesting a clinical improvement of muscular functions after treatment. Lingual frenulectomy and rehabilitation exercises seem to affect the function of the orofacial muscles. Improvement in muscle sEMG potentials after treatment was demonstrated by sEMG, which can be considered the correct method to monitor this intervention.