We demonstrate full selective control over the constructive or destructive character of fourth-order recurrent interferences in a modified version of a Hong-Ou-Mandel interferometer using comb-like two-photon states. The comb spectral/temporal structure is obtained by inserting an etalon cavity in the signal path of an entangled photon pair obtained by pulsed spontaneous parametric downconversion. Both a simple qualitative discussion and a complete theoretical derivation are used to explain and analyze the experimental data.PACS numbers: 42.50. Dv, 03.65.Ud In the original scheme by Hong, Ou, and Mandel (HOM) [1] two single photons from a spontaneous parametric down-conversion (SPDC) pair are sent to two input ports of a beam-splitter (BS) and coincidences are observed between the detection events on two detectors placed at the BS output ports. While varying the relative phase delay between the two beams, one can observe a dip in the coincidence signal when such a delay is shorter than the coherence time of the downconverted photons. This fourth-order interference effect takes place when two photons in the same mode arrive simultaneously at BS and can also be observed when they are emitted independently by a single-photon device [2]. However, when an entangled two-photon state is considered, it is the indistinguishability between two two-photon amplitudes leading to the same detector "firing scheme" that gives rise to fourth-order interferences, and this may happen even if the two single photons arrive at BS at two different times (with a delay which can be much longer than their coherence time) and follow two distinguishable optical paths to reach the detectors. The interference will be either destructive or constructive, resulting in a dip or a peak in the coincidence signal, depending on the phase difference between these two two-photon amplitudes, as first observed by the group of Shih [3,4,5,6].Here, by using comb-like entangled states in a modified version of the HOM setup, we are able to force the concurrent contribution of both (HOM-and Shih-type) kinds of interferences to the generation of finely controllable dips or peaks in a recurrent pattern. A variable delay line is inserted in the idler path while an etalon cavity is placed in the other beam path and modifies the temporal structure of the signal photon wavepacket. The two photon wavepackets are then mixed at BS and coincidence events between detectors D 1 and D 2 at its output ports are measured while scanning the delay line (see Fig.1 for a simplified scheme of the experiment). We demonstrate a full control over the constructive or destructive character of the recurrent fourth-order interferences by means of a tuning of the etalon cavity in an easy and simply predictable way. This type of measurement has been recently discussed in a theoretical paper by Peřina [7] and a somewhat related experiment with so-called mode-locked two-photon states has also been recently reported by Lu et al. [8].The etalon cavity is characterized by a comb-like spec...