Penicillin prophylaxis as an adjunct to the capping of pulps infected with Streptococcus mutans

Dentinogenic Specificity in the Preclinical Evaluation of Vital Pulp Treatment Strategies: A Critical Review

Reviews on the clinical performance of vital pulp treatment strategies and capping materials repeatedly showed an insufficient grade of evidence concerning their therapeutic validity. The biological mechanisms underlying the regenerative potential of pulp-dentin complex have attracted much attention during the last two decades, since new pulp treatment modalities have been designed and tested at the preclinical level. It has been recognized that evaluation should be based on the specific ability of therapeutic interventions to signal recruitment and differentiation of odontoblast-like cells forming a matrix in a predentin-like pattern, rather than uncontrolled hard tissue deposition in a scar-like form. The aim of the present article was to critically review data from histological experimental studies on pulp capping, published during the last 7 decades. A comprehensive literature search covering the period from 1949 to 2015 was done using the Medline/Pubmed database. Inclusion of a study was dependent on having sufficient data regarding the type of capping material used and the unit of observation (human permanent tooth in vivo or animal permanent dentition; primary teeth were excluded). The post-operatively deposited matrix was categorized into three types: unspecified, osteotypic, or dentin-like matrix. One hundred fifty-two studies were included in the final evaluation. Data from the present systematic review have shown that only 30.2% of the 152 experimental histological pulp capping studies described the heterogenic nature of the hard tissue bridge formation, including osteotypic and tubular mineralized tissue. Structural characteristics of the new matrix and the associated formative cells were not provided by the remaining 106 studies. Analysis showed that more careful preclinical evaluation with emphasis on the evidence regarding the dentinogenic specificity of pulp therapies is required. It seems that selection of appropriate vital pulp treatment strategies and pulp capping materials would be further facilitated in terms of their therapeutic validity if international consensus could be reached on a select number of mandatory criteria for tissue-specific dentinogenic events.

Pulp response to and cariogenicity of Lactobacillus casei in monoinfected gnotobiotic rats

The maxillary molar pulps of germ-free rats were mechanically exposed and suspensions of a strain of freshly grown Lactobacillus casei were applied to the pulp wounds. The pulps were left open to the oral environment, and the animals were maintained within the isolator until death. In the majority of teeth, pulp necrosis was evident and apical inflammation was present in 40% of the specimens. The remaining monoinfected animals were bred and the litters were placed on a 46% sucrose diet to determine the cariogenicity of the test strain of L. casei in the mandibular molars. The organism proved to be noncariogenic. The effects of mechanical exposure of the maxillary molars in these animals were similar to those observed in the direct-inoculation study, with the exception of a reduced incidence of apical inflammation.