Free sugars and gingival inflammation: A systematic review and meta-analysis

AIM

Consumption of free sugars has been associated with chronic non-communicable diseases. The aim of the study was to investigate the effect of free-sugar consumption on gingival inflammation using a systematic review and meta-analysis based on the PICO question 'What impact does the restriction of free sugars have on the inflammation of gingival tissue?'

MATERIALS AND METHODS

Literature review and analyses were based on the Cochrane Handbook for Systematic Reviews of Interventions. Controlled clinical studies reporting on free-sugar interventions and gingival inflammation were included. Risk of bias was performed with ROBINS-I and ROB-2, and effect sizes were estimated with robust variance meta-regressions.

RESULTS

Of the 1777 primarily identified studies, 1768 were excluded, and 9 studies with 209 participants with gingival inflammation measures were included. Six of these studies reported on the dental plaque scores of 113 participants. Restriction of free sugars, when compared with no such restriction, was associated with statistically significantly improved gingival health scores (standard mean difference [SMD] = -0.92; 95% confidence interval [CI]: -1.43 to -0.42, p < .004; I2 [heterogeneity] = 46.8) and a trend towards lower dental plaque scores (SMD = -0.61; 95% CI: -1.28 to 0.05, p < .07; I2  = 41.3). The observed improvement of gingival inflammation scores with restricted consumption of free sugar was robust against various statistical imputations. No meta-regression models were feasible because of the limited number of studies. The median publication year was 1982. Risk-of-bias analysis showed a moderate risk in all studies.

CONCLUSION

Restriction of free sugar was shown to be associated with reduced gingival inflammation. The systematic review was registered at PROSPERO (CRD 42020157914).

Cyclic CD8+ lymphopenia in dogs experimentally infected with Bartonella vinsonii subsp. berkhoffii

Until recently, it was presumed that Bartonella vinsonii only infected voles, a species of North American rodents. In April of 1993, however, our laboratory isolated a novel subspecies of B. vinsonii (B. vinsonii subsp. berkhoffii) from the blood of a dog diagnosed with vegetative valvular endocarditis. Subsequently, based on a seroepidemiologic survey of dogs from North Carolina and Virginia presenting for a variety of medical problems, we found evidence supporting a potentially important association between B. vinsonii and Ehrlichia canis co-infection in dogs. In the following study, eight dogs were infected with B. vinsonii: four specific pathogen free dogs and four dogs that had previously been infected with E. canis. Flow cytometric analysis of peripheral blood lymphocytes revealed a cyclic elevation of the CD4/CD8 T-cell ratio that correlated with cyclic CD8+ lymphopenia in all dogs infected with B. vinsonii, regardless of prior exposure to E. canis.

Thidiazuron-induced plant regeneration from protoplasts of Vicia faba cv. Mythos

Protoplasts of 10 cultivars of V. faba were isolated from etiolated shoot-tips and tested for their regeneration capacity. After purification, protoplasts were embedded in sodium alginate and cultivated in the medium of Kao and Michayluk (1975) containing 0.5 mg·1(-1) of each 2,4-dichlorophenoxyacetic acid, naphthylacetic acid and 6-benzylaminopurine. Depending on cultivar, division frequencies of up to 40% were obtained. Six weeks after embedding, protoplast-derived calluses were transferred to Gelrite-solidified media with different combinations of growth regulators. A two step protocol (auxin high/low) was tested for its ability to induce somatic embryogenesis. The formation of globular structures was observed, but no embryo formation could be achieved. In contrast, cultivation of protocalluses on medium supplemented with thidiazuron resulted in shoot development in cultivar Mythos. To generate mature plants, the shoots were grafted onto young seedlings. In order to optimize the in vitro-conditions, different concentrations of thidiazuron alone or in combination with naphthylacetic acid were tested, showing that an increase of thidiazuron and the addition of naphthylacetic acid positively affects both the viability of protocalluses and the regeneration frequency.